Lipid delivery particles and uses thereof

Abstract

Disclosed herein, in aspects, are compositions, methods, kits, and systems relating to delivery of payload into cells, for instance, for in vivo delivery via lipid delivery particles that comprise a chimeric envelope protein.

Description

WSGR Docket No.: 62697-751.601LIPID DELIVERY PARTICLES AND USES THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 736,030, filed December 19, 2024, U.S. Provisional Patent Application No. 63 / 767,421, filed March 5, 2025, U.S. Provisional Patent Application No. 63 / 805,072, filed May 13, 2025, and U.S. Provisional Patent Application No. 63 / 857,935, filed August 5, 2025, each of which is incorporated herein by reference in its entirety.BACKGROUND

[0002] Delivery of therapeutic payloads into the cells has been a significant challenge in drug development because payloads, such as proteins, cannot freely diffuse across the cell membrane. Although viral based constructs have been developed to deliver therapeutic payloads, these constructs often have low efficacy and / or create considerable side effects. There is a need for improved delivery of payloads into cells.SUMMARY

[0003] Disclosed herein, in some embodiments, is a lipid delivery particle comprising a lipid membrane encapsulating a cavity and a chimeric envelope protein on the lipid membrane, wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain, wherein the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain, wherein the cytoplasmic domain is heterologous to BaEV envelope protein surface unit and is a retrovirus envelope protein cytoplasmic domain, and wherein the cytoplasmic domain is not a MLV envelope protein cytoplasmic domain.

[0004] Also disclosed herein, in some embodiments, is a lipid delivery particle comprising a lipid membrane encapsulating a cavity and a chimeric envelope protein on the lipid membrane, wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises (i) a cleavage sequence that is recognizable by a Murine Leukemia Virus (MLV) pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit, (ii) a cleavage sequence that is recognizable by a Human Immunodeficiency Virus (HIV) pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit, or (iii) a cleavage sequence that is recognizable by a Feline Leukemia Virus (FeLV) pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit and wherein the R peptide is not a MLV envelope protein R peptide.

[0005] Also disclosed herein, in some embodiments, is a lipid delivery particle comprising: (a) a lipid membrane encapsulating a cavity; (b) a chimeric envelope protein on the lipid membrane; (c) a chimeric protein within the cavity, wherein the chimeric protein comprises a plasma membrane recruitmentWSGR Docket No.: 62697-751.601 element and a payload; wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain, wherein the cytoplasmic domain is heterologous to BaEV envelope protein surface unit and is a retrovirus envelope protein cytoplasmic domain, and wherein the payload comprises a payload protein.

[0006] Also disclosed herein, in some embodiments, is a lipid delivery particle comprising: (a) a lipid membrane encapsulating a cavity; (b) a chimeric envelope protein on the lipid membrane; (c) a chimeric protein within the cavity, wherein the chimeric protein comprises a plasma membrane recruitment element and a payload; wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, and wherein the transmembrane unit comprises a cleavage sequence that is recognizable by a Murine Leukemia Virus (MLV) pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit; and wherein the payload comprises a payload protein.

[0007] In some embodiments, the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide. In some embodiments, the transmembrane unit further comprises a R peptide, wherein the R peptide is not a MLV envelope protein R peptide. In some embodiment, the transmembrane unit further comprises a R peptide, wherein the R peptide is not a HIV envelope protein R peptide.

[0008] In some embodiments, the transmembrane unit further comprises a cleavage sequence that is recognizable by a MLV pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit. In some embodiment, the transmembrane unit further comprises a cleavage sequence that is recognizable by a HIV pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit. In some embodiment, the transmembrane unit further comprises a cleavage sequence that is recognizable by a FeLV pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit. In some embodiment, the cleavage sequence comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 236-243.

[0009] In some embodiments, the R peptide is a retrovirus envelope protein R peptide. In some embodiments, the R peptide is a gamma retrovirus envelope protein R peptide.

[0010] In some embodiments, the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain. In some embodiments, the surface unit and the R peptide are from different species of virus. In some embodiments, the surface unit and the cytoplasmic domain are from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species ofWSGR Docket No.: 62697-751.601 virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species of virus. In some embodiments, the R peptide is an MLV envelope protein R peptide.

[0011] In some embodiments, the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 55.

[0012] In some embodiments, the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 56.

[0013] In some embodiments, the cytoplasmic domain is an MLV envelope protein cytoplasmic domain. In some embodiments, the transmembrane domain comprises an MLV envelope protein transmembrane domain.

[0014] In some embodiments, the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 158.

[0015] In some embodiments, the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 160.

[0016] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 157.

[0017] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 159.

[0018] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 174.

[0019] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 190.WSGR Docket No.: 62697-751.601

[0020] In some embodiments, the R peptide is not an MLV envelope protein R peptide. In some embodiments, the cytoplasmic domain is not an MLV envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain. In some embodiments, the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide.

[0021] In some embodiments, the cytoplasmic domain and the R peptide comprise: a FeLV envelope protein cytoplasmic domain and a FeLV envelope protein R peptide, respectively; a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively; a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively.

[0022] In some embodiments, the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope protein transmembrane domain, a KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or a WMSV envelope protein transmembrane domain.

[0023] In some embodiments, the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

[0024] In some embodiments, the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76.

[0025] In some embodiments, the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 57, 59, 250, 254, 258, 262, 266, 270, and 274.

[0026] In some embodiments, the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 54, 58, and 60.

[0027] In some embodiments, the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%,WSGR Docket No.: 62697-751.601 at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115.

[0028] In some embodiments, the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

[0029] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.

[0030] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

[0031] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, 180, 244, 247, 251, 255, 259, 263, 267, and 271.

[0032] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, 196, 275, 277, 279, 281, 282, 284, 286, 288.

[0033] In some embodiments, the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227.

[0034] In some embodiments, the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.WSGR Docket No.: 62697-751.601

[0035] In some embodiments, the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117.

[0036] In some embodiments, the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118.

[0037] In some embodiments, the lipid delivery particle comprises a viral structural protein. In some embodiments, the viral structural protein comprises a gag protein. In some embodiments, the viral structural protein comprises a gag / pro polyprotein. In some embodiments, the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof. In some embodiments, the gag / pro polyprotein is a gag / pro polyprotein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof. In some embodiments, the gag protein is a MMLV gag protein.

[0038] In some embodiments, the gag / pro polyprotein is a MMLV gag / pro polyprotein.

[0039] In some embodiments, the viral structural protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 or 285-305.

[0040] In some embodiments, the viral structural protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

[0041] In some embodiments, the lipid delivery particle comprises comprising a payload. In some embodiments, the payload comprises a payload protein. In some embodiments, the lipid delivery particle comprises a chimeric protein comprising the plasma membrane recruitment element and the payload protein. In some embodiments, the plasma membrane recruitment element is fused with the payload protein in order from N-terminus to C-terminus. In some embodiments, the lipid delivery particleWSGR Docket No.: 62697-751.601 comprises a plurality of the chimeric proteins. In some embodiments, the chimeric protein further comprises a nuclear export signal (NES).

[0042] In some embodiments, the plasma membrane recruitment element, the NES, and the payload protein are arranged in order from N-terminus to C-terminus. In some embodiments, the chimeric protein further comprises a linker. In some embodiments, the linker is a cleavable linker. In some embodiments, the cleavable linker is positioned between the plasma membrane recruitment element and the payload protein. In some embodiments, the cleavable linker is positioned between the NES and the payload protein. In some embodiments, a nuclear localization signal (NLS) is present at C-terminus of the cleavable linker.

[0043] In some embodiments, the chimeric protein comprises, from N-terminus to C-terminus: [the plasma membrane recruitment element]-[the cleavable linker]-[the payload protein];[the plasma membrane recruitment element]- [n* the NES] -[the cleavable linker]-[the payload protein]; [the plasma membrane recruitment element]-[the cleavable linker]-[the payload protein]-[n* the NES]; [the plasma membrane recruitment element]-[the cleavable linker]-[n* the NES]-[the payload protein]; [the plasma membrane recruitment element]-[a first cleavable linker]-[the payload protein]-[a second cleavable linker]-[n* the NES];[the payload protein]-[the cleavable linker]-[n* the NES]-[the plasma membrane recruitment element]; [the payload protein]-[n* the NES]- [the cleavable linker]-[the plasma membrane recruitment element]; [n* the NES]-[the payload protein]-[the cleavable linker]-[the plasma membrane recruitment element]; [n* the NES]-[a first cleavable linker]-[the payload protein]-[a second cleavable linker]-[the plasma membrane recruitment element]; or[the payload protein]-[a first cleavable linker]-[the plasma membrane recruitment element]; wherein n represents an integer from 1 to 20.

[0044] In some embodiments, at least a plurality of the payload protein present in the lipid delivery particle is free from fusion. In some embodiments, the lipid delivery particle further comprises a cleavage product that comprises the plasma membrane recruitment element but not the payload protein. In some embodiments, the plasma membrane recruitment element comprises a viral structural protein. In some embodiments, the viral structural protein comprises a gag protein. In some embodiments, the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof. In some embodiments, the gag protein is a MMLV gag protein. In some embodiments, the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%,WSGR Docket No.: 62697-751.601 at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 or 285-305.

[0045] In some embodiments, the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

[0046] In some embodiments, the payload protein comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof. In some embodiments, the payload protein comprises a guidable polypeptide. In some embodiments, the guidable polypeptide is capable of binding to a polynucleotide. In some embodiments, the polynucleotide directs the guidable polypeptide to a sequence in a target nucleic acid molecule. In some embodiments, the guidable polypeptide is a Cas protein. In some embodiments, the Cas protein is a Cas9 protein or a Cas 12 protein. In some embodiments, the polynucleotide comprises a spacer sequence, wherein the spacer sequence is complementary to a target sequence in the target nucleic acid molecule and wherein the spacer sequence is capable of hybridizing to the target sequence.

[0047] In some embodiments, the polynucleotide comprises a CRISPR RNA (crRNA), a tracrRNA, or a scoutRNA encoded in a CRISPR system. In some embodiments, the polynucleotide comprises a single RNA guide (sgRNA) comprising the crRNA and the tracrRNA.

[0048] In some embodiments, the lipid delivery particle further comprises a targeting moiety, and wherein the chimeric envelope protein is fused with a targeting moiety or the targeting moiety is anchored to the lipid membrane separately from the chimeric envelope protein. In some embodiments, the targeting moiety recognizes a specific molecule on the surface of a target cell. In some embodiments, the specific molecule is CD 133. In some embodiments, the targeting moiety is an antibody or an antigen-binding fragment thereof, an antigen-binding fibronectin type III (Fn3) scaffold, a ligand, a cytokine, a chemokine, or a T cell receptor (TCRs). In some embodiments, the targeting moiety is the antibody or the antigen-binding fragment thereof, and wherein the antibody or the antigen-binding fragment thereof is a Fab, a Fab', a F(ab')2, Fv fragments, scFv antibody fragments, disulfide -linked Fvs (sdFv), a Fd fragment, a linear antibody, a single domain antibody, a nanobody, or came lid VHH domains.

[0049] Also disclosed herein, in some embodiments, is a composition comprising a first nucleic acid sequence encoding a chimeric envelope protein, wherein the chimeric envelope comprises a Baboon Endogenous Retrovirus (BaEV) surface unit and a transmembrane unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises a cleavage sequence recognizable by a Murine Leukemia Virus (MLV) protease so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit, and wherein the R peptide is not a MLV envelope protein R peptide. In some embodiments, the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide. In some embodiments, the cytoplasmic domain is not a MLV envelope protein cytoplasmic domain. In someWSGR Docket No.: 62697-751.601 embodiments, the R peptide is a retrovirus envelope protein R peptide. In some embodiments, the R peptide is a gamma retrovirus envelope protein R peptide. In some embodiments, the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain. In some embodiments, the surface unit and the R peptide are from different species of virus. In some embodiments, the surface unit and the cytoplasmic domain are from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species of virus. In some embodiments, the surface unit and the cytoplasmic domain are from different species of virus. In some embodiments, the surface unit and the R peptide are from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species of virus. In some embodiments, the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain. In some embodiments, the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide.

[0050] In some embodiments, the cytoplasmic domain and the R peptide comprise: a FeLV envelope protein cytoplasmic domain and a FeLV envelope protein R peptide, respectively; a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively; a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively.

[0051] In some embodiments, the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope protein transmembrane domain, a KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or a WMSV envelope protein transmembrane domain.

[0052] In some embodiments, the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

[0053] In some embodiments, the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76.

[0054] In some embodiments, the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 57, 59, 250, 254, 258, 262, 266, 270, and 274.WSGR Docket No.: 62697-751.601

[0055] In some embodiments, the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 54, 58, and 60.

[0056] In some embodiments, the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117.

[0057] In some embodiments, the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118.

[0058] In some embodiments, the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115.

[0059] In some embodiments, the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

[0060] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.

[0061] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

[0062] In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, 180, 244, 247, 251, 255, 259, 263, 267, and 271.

[0063] In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%,WSGR Docket No.: 62697-751.601 at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, 196, 275, 277, 279, 281, 282, 284, 286, 288.

[0064] In some embodiments, the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227.

[0065] In some embodiments, the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.

[0066] In some embodiments, the composition comprises a second nucleic acid sequence encoding a plasma membrane recruitment element. In some embodiments, the plasma membrane recruitment element comprises a viral structural protein. In some embodiments, the plasma membrane recruitment element comprises a gag protein. In some embodiments, the plasma membrane recruitment element comprises a gag / pro polyprotein. In some embodiments, the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

[0067] In some embodiments, the gag / pro protein is a gag / pro polyprotein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof. In some embodiments, the gag protein is a MMLV gag protein. In some embodiments, the gag / pro polyprotein is a MMLV gag / pro polyprotein.

[0068] In some embodiments, the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 or 285- 305.WSGR Docket No.: 62697-751.601

[0069] In some embodiments, the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

[0070] In some embodiments, the composition further comprising a third nucleic acid sequence encoding a payload. In some embodiments, the payload comprises a payload protein. In some embodiments, the payload protein comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof. In some embodiments, the payload comprises a guidable polypeptide. In some embodiments, the guidable polypeptide is capable of binding to a polynucleotide. In some embodiments, the polynucleotide directs the guidable polypeptide to a sequence in a target nucleic acid molecule. In some embodiments, the guidable polypeptide is a Cas protein. In some embodiments, the Cas protein is a Cas9 protein or a Casl2 protein. In some embodiments, the polynucleotide comprises a spacer sequence, wherein the spacer sequence is complementary to a target sequence in the target nucleic acid molecule and wherein the spacer sequence is capable of hybridizing to the target sequence. In some embodiments, the polynucleotide comprises a CRISPR RNA (crRNA), a tracrRNA, or a scoutRNA encoded in a CRISPR system. In some embodiments, the polynucleotide comprises a single RNA guide (sgRNA) comprising the crRNA and the tracrRNA. In some embodiments, the composition comprises a fourth nucleic acid sequence encoding a nuclear export signal (NES). In some embodiments, the second nucleic acid sequence, the fourth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5 ’ to 3 ’ . In some embodiments, the composition comprises a fifth nucleic acid sequence encoding a linker. In some embodiments, the linker is a cleavable linker. In some embodiments, the second nucleic acid sequence, the fifth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5’ to 3’. In some embodiments, the second nucleic acid sequence, the fourth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5 ’ to 3 ’ .

[0071] In some embodiments, the composition comprises a sixth nucleic acid sequence encoding a nuclear localization signal (NLS). In some embodiments, the fifth nucleic acid sequence and the sixth nucleic acid sequence are arranged in order from 5 ’ to 3 ’ . In some embodiments, the composition comprises a seventh nucleic acid sequence encoding a targeting moiety.

[0072] In some embodiments, the targeting moiety recognizes a specific molecule on the surface of a target cell. In some embodiments, the specific molecule is CD133. In some embodiments, the targeting moiety is an antibody or an antigen-binding fragment thereof, an antigen-binding fibronectin type III (Fn3) scaffold, a ligand, a cytokine, a chemokine, or a T cell receptor (TCRs). In some embodiments, the targeting moiety is the antibody or the antigen-binding fragment thereof, and wherein the antibody or the antigen-binding fragment thereof is a Fab, a Fab', a F(ab')2, Fv fragments, scFv antibody fragments, disulfide-linked Fvs (sdFv), a Fd fragment, a linear antibody, a single domain antibody, a nanobody, or camelid VHH domains.WSGR Docket No.: 62697-751.601

[0073] Also disclosed herein, in some embodiments, is a composition comprising nucleic acid sequences encoding proteins capable of forming the lipid delivery particle of described herein when the nucleic acid sequences are expressed in a producer cell.

[0074] Also disclosed herein, in some embodiments, is a chimeric protein comprising a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises (a) a cleavage sequence recognizable by a Murine Leukemia Virus (MLV) pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit, (b) a cleavage sequence that is recognizable by a Human Immunodeficiency Virus (HIV) pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit, or (c) a cleavage sequence recognizable by a Feline Leukemia Virus (FeLV) pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit; and wherein the R peptide is not a MLV envelope protein R peptide or a HIV envelope protein R peptide.

[0075] In some embodiments, the surface unit and the R peptide are associated by noncovalent interactions or by disulfide bonds. In some embodiment, the cleavage sequence comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 236-243.

[0076] In some embodiments, the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide. In some embodiments, the cytoplasmic domain is not a MLV envelope protein cytoplasmic domain. In some embodiments, the R peptide is a retrovirus envelope protein R peptide. In some embodiments, the R peptide is a gamma retrovirus envelope protein R peptide. In some embodiments, the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain. In some embodiments, the surface unit and the R peptide are from different species of virus. In some embodiments, the surface unit and the cytoplasmic domain are from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species of virus. In some embodiments, the surface unit and the cytoplasmic domain are from different species of virus. In some embodiments, the surface unit and the R peptide are from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are from the same species of virus. In some embodiments, the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain. In some embodiments, the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide. In some embodiments, the cytoplasmic domain and the R peptide comprise: a FeLV envelope protein cytoplasmic domain and aWSGR Docket No.: 62697-751.601FeLV envelope protein R peptide, respectively; a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively; a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively. In some embodiments, the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope protein transmembrane domain, a KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or a WMSV envelope protein transmembrane domain. In some embodiments, the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some embodiments, the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76. In some embodiments, the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51,53, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some embodiments, the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52,54, 58, and 60. In some embodiments, the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117. In some embodiments, the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118. In some embodiments, the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115. In some embodiments, the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, atWSGR Docket No.: 62697-751.601 least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some embodiments, the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, 180, 244, 247, 251, 255, 259, 263, 267, and 271. In some embodiments, the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, 196, 275, 277, 279, 281, 282, 284, 286, 288. In some embodiments, the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227. In some embodiments, the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.

[0077] Also disclosed herein, in some embodiments, is a vector comprising the composition described herein. Also disclosed herein, in some embodiments, is a cell comprising the composition or the vector described herein.

[0078] Also disclosed herein, in some embodiments, is a pharmaceutical composition comprising the lipid delivery particle, the composition, the vector, or the cell described herein, and a pharmaceutically acceptable excipient, diluent, or vehicle.

[0079] Also disclosed herein, in some embodiments, is a kit comprising the lipid delivery particle, the composition, the vector, the cell, or the pharmaceutical composition described herein, and an information material.

[0080] Also disclosed herein, in some embodiments, is a method of producing the lipid delivery particle described herein, the method comprising providing a producer cell comprising a nucleic acid molecule encoding proteins capable of forming the lipid delivery particle, and using the producer cell to produce the lipid delivery particle described herein.WSGR Docket No.: 62697-751.601

[0081] Also disclosed herein, in some embodiments, is a method of producing the lipid delivery particle described herein, the method comprising providing the composition, and using the producer cell to produce the lipid delivery particle described herein.

[0082] Also disclosed herein, in some embodiments, is a method of treating a disease in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of the lipid delivery particle, the composition, the vector, the cell, or the pharmaceutical composition described herein, thereby treating the disease in the subject.

[0083] Also disclosed herein, in some embodiments, is a method of editing a nucleic acid molecule in a cell, the method comprising contacting a cell with the lipid delivery particle described herein.

[0084] Also disclosed herein, in some embodiments, is a method of delivering a payload to a target cell, the method comprising contacting a cell with the lipid delivery particle described herein.

[0085] In some embodiments, the lipid delivery particle substantially avoids fusing with membrane of hepatocytes. In some embodiments, the lipid delivery particle substantially avoids delivering a payload of the lipid delivery particle into hepatocytes.INCORPORATION BY REFERENCE

[0086] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.BRIEF DESCRIPTION OF THE DRAWINGS

[0087] The novel features of the disclosure are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings of which:

[0088] FIG. 1 depicts exemplary constructs of the chimeric envelope proteins described herein.

[0089] FIG. 2 depicts a schematic of chimeric envelope protein screening using a Moloney murine leukemia virus (MMLV) platform.

[0090] FIG. 3A depicts percentage of GFP+ HEK293T cells after delivery of MMLV vectors with envelope protein construct BaEV-VSV C, BaEV-W480 C, BaEV-FeLV C, BaEV-GALV C, BaEV-KRV C, BaEV-ReEV C, BaEV-WMSV C, BaEV WT, BaEV-Rless, BaEV-TR, or VSV-G. FIG. 3B depicts titer (functional units / mL) in HEK293T cells after delivery of lipid delivery particles with envelope protein construct BaEV-VSV C, BaEV-W480 C, BaEV-FeLV C, BaEV-GALV C, BaEV-KRV C, BaEV- ReEV C, BaEV-WMSV C, BaEV WT, BaEV-Rless, BaEV-TR, or VSV-G.

[0091] FIG. 4A depicts percentage of GFP+ HEK293T cells after delivery of MMLV vectors with envelope protein construct BaEV-VSV TM+C, BaEV-W480 TM+C, BaEV-FELV TM+C, BaEV-GALV TM+C, BaEV-KRV TM+C, BaEV-ReEV TM+C, BaEV-WMSV TM+C, BaEV -MMLV TM+C, BaEVWSGR Docket No.: 62697-751.601WT, BaEV-Rless, BaEV-TR, or VSV-G. FIG. 4B depicts titer (functional units / mL) in HEK293T cells after delivery of lipid delivery particles with envelope protein construct BaEV-VSV TM+C, BaEV-W480 TM+C, BaEV-FELV TM+C, BaEV-GALV TM+C, BaEV-KRV TM+C, BaEV-ReEV TM+C, BaEV- WMSV TM+C, BaEV-MMLV TM+C, BaEV WT, BaEV-Rless, BaEV-TR, or VSV-G.

[0092] FIG. 5A-5B depict physical titer (FIG. 5A) and normalized vector potency (FIG. 5B) of MMLV vectors containing envelope protein construct BaEV-VSV C, BaEV-W480 C, BaEV-FeLV C, BaEV- GALV C, BaEV-KRV C, BaEV-ReEV C, BaEV-WMSV C, BaEV WT, BaEV-Rless, BaEV-TR, or VSV-G.

[0093] FIG. 6 depicts Cas9 concentration of lipid delivery particles with chimeric envelope protein.

[0094] FIGs. 7A-7B depict efficiency of B2M knockout of lipid delivery particles with chimeric envelope protein and Cas9 payload in HEK293T and hHSPC cells. FIG. 7A shows percentage of B2M- cells in transduced hHSPC cells treated with Vectofusin-1. FIG. 7B shows percentage of B2M- cells in transduced HEK293T cells.

[0095] FIGs. 8A-8B depict editing at the B2M locus in cells following treatment with lipid delivery particles with chimeric envelope protein and adenine base editor payload. FIG. 8A shows percentage of edited cells in transduced hHSPC cells treated with Vectofusin-1. FIG. 8B shows percentage of edited cells in transduced HEK293T cells.

[0096] FIGs. 9A-9B depict editing at the B2M locus in cells following treatment with lipid delivery particles with chimeric envelope protein and adenine base editor payload in primary human or cynomolgus hepatocytes. FIG. 9A shows percentage of edited cells in transduced primary human hepatocytes. FIG. 9B shows percentage of edited cells in transduced primary cynomolgus hepatocytes.

[0097] FIG. 10. shows multiplex editing efficiency of B2M and BCL11A of lipid delivery particles with chimeric envelope protein and adenine base editor payload in hHSPC cells.

[0098] FIG. 11. shows multiplex editing efficiency of B2M and BCL11A of lipid delivery particles with chimeric envelope protein and adenine base editor payload in HEK293T cells.

[0099] FIGs. 12A-12C depict efficiency of B2M knock-down of lipid delivery particles containing an adenine base editor payload and chimeric envelope protein BaEV-TR, BaEv-FeLV C, or BaEv-KRV C with anti-CD133 scFv in hHSPCs not treated with Vectofiisin-1. FIG. 12A shows percentage of B2M- hHSPCs following transduction lipid delivery particles containing an adenine base editor payload and chimeric envelope protein BaEV-TR with anti-CD133 scFv. FIG. 12B shows percentage of B2M- hHSPCs following transduction lipid delivery particles containing an adenine base editor payload and chimeric envelope protein BaEV-FeLV C with anti-CD133 scFv. FIG. 12C shows percentage of B2M- hHSPCs following transduction lipid delivery particles containing an adenine base editor payload and chimeric envelope protein BaEV-KRV C with anti-CD133 scFv.

[0100] FIGs. 13A-13B depict efficiency of base editing B2M using lipid delivery particles with envelope protein construct BaEV-TR or VSV-G. FIG. 13A shows efficiency of in vitro editing of HEK293T cell. FIG. 13B shows efficiency of in vitro editing of resting human hematopoietic stem andWSGR Docket No.: 62697-751.601 progenitor cells (HSPCs). Lipid delivery particles with the BaEV-TR envelope protein construct showed high tropism for resting human HSPCs.

[0101] FIGs. 14A-14B show results of a complement inactivation assay using lipid delivery particles with envelope protein construct BaEV-TR or VSV-G. Testing was conducted with human serum (FIG. 14A) or cynomolgus serum (FIG. 14B). FIG. 14A shows efficiency of in vitro editing of Huh7 cells with human serum. FIG. 14B shows efficiency of in vitro editing of Huh7 cells with cynomolgus serum. Particles were tested with heat inactivation (“HI”) or no heat inactivation (“Non HI”).

[0102] FIGs. 15A-15C depict in vivo testing of lipid delivery particles in human bone marrow (BM) HSPC upon intravenous (IV) vector dosing. FIG. 15A shows a schematic representation of the experimental design. FIG. 15B shows a graph summarizing the efficiency of B2M knockout measured by flow cytometry. Vector constructs were tested across four conditions (1) on total human BM cells, (2) on human BM lymphoid cells, (3) on human BM myeloid cells, and (4) on human BM HSPC. For each condition, the bars from left to right represent (i) BaEVTR administered at 69 pmol, (ii) BaEVTR administered at 150 pmol, (iii) VSV-G administered at 69 pmol, and (iv) untreated (UT) with no vectors or particles administered. FIG. 15C shows editing efficiency of B2M measured by next-generation sequencing. Editing efficiency was measured on total human BM cells.

[0103] FIGs. 16A-16C depict testing of vector dosing over 1 or 3 days and with or without addition of Vectofusin-1 (VF1), a peptidic viral transduction enhancer. FIG. 16A shows a schematic representation of the experimental design. FIG. 16B shows efficiency of B2M knockout measured by flow cytometry. Vector constructs were tested across the same four conditions as FIG. 15B. For each condition, the bars from left to right represent (i) BaEVTR administered lx with VF1, (ii) BaEVTR administered at lx titer without VF1, (iii) BaEVTR administered at 3x titer with VF1, (iv) BaEVTR administered at 3x titer without VF1, and (v) untreated (UT) with no vectors or particles administered. FIG. 16C shows editing efficiency of B2M knockout measured by next-generation sequencing. Editing efficiency was measured on total human BM cells.

[0104] FIG. 17 depicts efficiency of multiplex editing of resting human HPSC in vitro using lipid delivery particles with envelope protein construct BaEV-TR. Multiplex editing of B2M and BCL11A was tested with Cas9 payload.

[0105] FIG. 18 depicts in vivo multiplex editing efficiency of B2M knockout and BCL11A knockout in bone marrow (BM) huCD45+ cells. Editing was performed using lipid delivery particles with envelope protein construct BaEV-TR and Cas9 payload. The eight bars from left to right represent: (i) B2M single editing (i.e., only B2M gRNA was delivered by the delivery particles), (ii) BCL11A single editing (i.e., only BCL11A gRNA), (iii) B2M single editing, (iv) BCL11A single editing, (v) B2M multiplex editing (i.e., with both B2M and BCL11A gRNAs), (vi) BCL11A multiplex editing (i.e., with B2M and BCL11A gRNAs), (vii) B2M editing in untreated (UT) cells with no vectors or particles administered, and (viii) BCL11A editing in untreated (UT) cells with no vectors or particles administered.WSGR Docket No.: 62697-751.601

[0106] FIGs. 19A-19B depict avoidance of human hepatocytes in vitro by lipid delivery particles with envelope protein construct BaEV-TR or VSV-G. FIG. 19A shows efficiency of in vitro B2M editing of resting HSPC. FIG. 19B shows efficiency of in vitro B2M editing of human hepatocytes.

[0107] FIGs. 20A-20B depict testing of lipid delivery particles comprising envelope protein construct BaEV-TR or VSV-G in the FRG humanized liver model. FIG. 20A shows a schematic representation of the experimental design. FIG. 20B shows in vivo editing efficiency of bulk liver, specifically percentage of B2M edited of GFP+ labeled cells. The bars, from left to right, represent BaEVTR pseudotyped delivery particles administered at 125 pmol, (ii) VSV-G pseudotyped delivery particles administered at 125 pmol, (iii) VSV-G pseudotyped lentiviral vector (LV), and (iv) untreated (UT) with no vectors or particles administered.

[0108] FIGs. 21A-21D depict testing of lipid delivery particles with envelope protein construct BaEV- TR or VSV-G. BaEV-TR particles were tested with or without Vectofiisin-1 (VF). FIG. 21A shows a schematic representation of the experimental design. Particles contained adenine base editor (ABE) and B2M gRNAs. FIG. 21B shows human chimerism as percentage of huCD45 -positive cells (%huCD45+). Human chimerism was measured in BM, spleen (SPL), and peripheral blood (PB). BM was fully humanized and PB and spleen showed high human chimerism at Week 12. FIG. 21C shows bone marrow (BM) HSPC composition at Week 12. HSPC composition was tested for hematopoietic stem cells (HSC), multipotent progenitors (MPP), multi-lymphoid progenitors (MLP), early T cell progenitors (ETP), common myeloid progenitors / megakaryocytes-erythroid progenitors (CMP-MEP), granulocytes / macrophage progenitors (GMP), and pre-B / NK progenitors (preBNK). FIG. 21D shows mature blood cells composition of BM at Week 12. T cells (T), B cells (B), myelocytes (Myelo), monocytes (Mono), and platelets were tested. For FIGs. 21B-21D, for each condition, the bars from left to right represent (i) saline, (ii) BaEVTR with Vectofusin-1 (BaEVTR + VF), (iii) BaEVTR without Vectofusin-1 (BaEVTR), and (iv) VSV-G.

[0109] FIGs. 22A-22C depict B2M editing efficiency of human CD45+ cells in bone marrow (BM; FIG. 22A), peripheral blood (PB; FIG. 22B), and spleen (SPL; FIG. 22C). In vivo editing of cells using lipid delivery particles with envelope protein construct BaEV-TR or VSV-G, or BaEV-TR particles was tested with or without Vectofusin-1 (VF1). For FIGs. 22A-22C, for each condition, the bars from left to right represent (i) BaEVTR with Vectofusin-1 administered 3x at 125 pmol each time (BaEVTR +VF1), (ii) BaEVTR without Vectofusin-1 administered 3x at 125 pmol each time (BaEVTR -VF1), (iii) VSV-G administered 3x at 125 pmol each time, and (iv) untreated (UT) with no vectors or particles administered.

[0110] FIGs. 23A-23B depict efficiency of B2M knockout using lipid delivery particles with envelope protein BaEVTR, chimeric envelope protein BaEV and Feline Leukemia Virus (BaEVX-1), chimeric envelope protein BaEV and Koala Retrovirus (BaEVX-2), or VSV-G. Lipid delivery particles were tested with various concentrations of Cas9 payload. FIG. 23A shows in vitro editing of resting HSPC with Vectofusin-1. FIG. 23B shows in vitro editing efficiency of resting HSPC without Vectofusin-1.

[0111] FIGs. 24A-24C depict testing of lipid delivery particles with chimeric envelope proteins in vivo in a short-term humanization model using NBSGW mice. FIG. 24A shows a schematic representation ofWSGR Docket No.: 62697-751.601 the experimental design. FIG. 24B shows efficiency of B2M knockout in BM huCD45+ cells. Percentage of B2M-negative cells was measured following administration of lipid delivery particles with (i) envelope protein BaEVTR, (ii) chimeric envelope protein BaEV and Feline Leukemia Virus (BaEVX-1), or (iii) chimeric envelope protein BaEV and Koala Retrovirus (BaEVX-2). For reference, the BaEVX-1 particles can be referred to as BaEV-FeLV C particles, and the BaEVX-2 particles can be referred to as BaEV- KRV C particles. Saline was used as a control. FIG. 24C shows B2M editing efficiency in HSPCs. B2M editing was tested for lineage -negative hematopoietic stem and progenitor cells (Lin-), CD34+ HSPC, hematopoietic stem cells (HSC), multipotent progenitors (MPP), multi-lymphoid progenitors (MLP), early T cell progenitors (ETP), common myeloid progenitors / megakaryocytes-erythroid progenitors (CMP-MEP), granulocytes / macrophage progenitors (GMP), and pre-B / NK progenitors (preBNK). For FIGs. 24B-24C, bars from left to right for each condition represent BaEVTR, BaEVX-1, BaEVX-2, and Saline.

[0112] FIGs. 25A-25B depict hepatocyte avoidance using lipid delivery particles with chimeric envelope proteins and Cas9 payload. Particles were tested with or without addition of Vectofusin-1. FIG. 25A shows in vitro editing efficiency of primary human hepatocytes with Vectofiisin-1. FIG. 25B shows in vitro editing efficiency of primary human hepatocytes without Vectofiisin-1. BaEVX-1 represents chimeric envelope protein BaEV and Feline Leukemia Virus (FLV) and BaEVX-2 represents chimeric envelope protein BaEV and Koala Retrovirus (KRV).

[0113] FIGs. 26A-26B depict results measuring the potency and specificity of lipid delivery particles with chimeric envelope proteins in cynomolgus primary cells. Cas9 was used as the payload. FIG. 26A shows in vitro B2M editing of cynomolgus HSPC without Vectofiisin-1. FIG. 26B shows in vitro editing of cynomolgus hepatocytes without Vectofiisin-1. BaEVX-1 represents chimeric envelope protein BaEV and Feline Leukemia Virus (FLV) and BaEVX-2 represents chimeric envelope protein BaEV and Koala Retrovirus (KRV).

[0114] FIGs. 27A-27D depict in vitro editing B2M editing efficiency in resting HSPC using lipid delivery particles with envelope protein BaEVTR, chimeric envelope protein BaEV and Feline Leukemia Virus (BaEVX-1), chimeric envelope protein BaEV and Koala Retrovirus (BaEVX-2), or VSV-G. CD133 was added as a targeting ligand to examine its effects of transduction. FIG. 27A shows efficiency of B2M knockout using lipid delivery particles with envelope protein BaEVTR without CD 133 (BaEVTR), a first run of BaEVTR with CD 133 (BaEVTR_CD133_vl), and a second run of BaEVTR with CD 133 (BaEVTR_CD133_v2). FIG. 27B shows efficiency of B2M knockout using lipid delivery particles with VSV-G envelope construct and no CD 133 ligand (VSV-G), a first run with VSV-G and CD 133 ligand (VSV-GMut_CD133L_vl), and a second run with VSV-G and CD133 ligand (VSV-GMut_CD133L_v2). FIG. 27C shows efficiency of B2M knockout using lipid delivery particles with chimeric envelope protein BaEV and Feline Leukemia Virus without CD133 (BaEVX-1), a first run of BaEVX-1 with CD133 (BaEVX-l_CD133L_vl), and a second run of BaEVX-1 with CD133 (BaEVX-l_CD133L_v2). FIG. 27D shows efficiency of B2M knockout using lipid delivery particles with chimeric envelope protein BaEV and Koala Retrovirus without CD133 (BaEVX-2), a first run of BaEVX-2 with CD133WSGR Docket No.: 62697-751.601(BaEVX-2_CD133L_vl), and a second run of BaEVX-2 with CD133 (BaEVX-2_CD133L_v2). All experiments performed without the addition of Vectofusin-1.

[0115] FIGs. 28A-28D depict in vitro B2M editing in human hepatocytes using lipid delivery particles with envelope protein BaEVTR, chimeric envelope protein BaEV and Feline Leukemia Virus (BaEVX- 1), chimeric envelope protein BaEV and Koala Retrovirus (BaEVX-2), or VSV-G. CD133 was added as a targeting ligand to examine its effects of transduction. FIG. 28A shows efficiency of B2M knockout using lipid delivery particles with envelope protein BaEVTR without CD 133 (BaEVTR), a first run of BaEVTR with CD133 (BaEVTR_CD133_vl), and a second run of BaEVTR with CD133 (BaEVTR_CD133_v2). FIG. 28B shows efficiency of B2M knockout using lipid delivery particles with VSV-G envelope construct and no CD133 ligand (“VSV-G”), a first run with VSV-G and CD133 ligand (“VSV-GMut_CD133L_vl”), and a second run with VSV-G and CD133 ligand (“VSV- GMut_CD133L_v2”). FIG. 28C shows efficiency of B2M knockout using lipid delivery particles with chimeric envelope protein BaEV and Feline Leukemia Virus without CD133 (BaEVX-1), a first run of BaEVX-1 with CD133 (BaEVX-l_CD133L_vl), and a second run of BaEVX-1 with CD133 (BaEVX- l_CD133L_v2). FIG. 28D shows efficiency of B2M knockout using lipid delivery particles with chimeric envelope protein BaEV and Koala Retrovirus without CD 133 (BaEVX-2), a first run of BaEVX- 2 with CD133 (BaEVX-2_CD133L_vl), and a second run of BaEVX-2 with CD133 (BaEVX- 2_CD133L_v2). All experiments performed without the addition of Vectofiisin-1.

[0116] FIGs. 29-30 depict testing of lipid delivery particles with chimeric envelope proteins in vivo in a long-term humanization model using NBSGW mice. FIG. 29 shows the HSPC composition in BM. HSPC composition was tested for hematopoietic stem cells (HSC), multipotent progenitors (MPP), multilymphoid progenitors (MLP), early T cell progenitors (ETP), common myeloid progenitors / megakaryocytes-erythroid progenitors (CMP-MEP), granulocytes / macrophage progenitors (GMP), and pre-B / NK progenitors (preBNK). Human chimerism was measured as percentage of huCD45 -positive cells (%huCD45+) and was measured in BM, spleen (SPL), and peripheral blood (PB). FIG. 30 shows B2M editing efficiency in HSPCs. For reference, the BaEVX-1 particles can be referred to as BaEV-FeLV C particles, and the BaEVX-2 particles can be referred to as BaEV-KRV C particles. Saline was used as a control. B2M editing was tested for lineage-negative hematopoietic stem and progenitor cells (Lin-), CD34+ HSPC, hematopoietic stem cells (HSC), multipotent progenitors (MPP), multi-lymphoid progenitors (MLP), early T cell progenitors (ETP), common myeloid progenitors / megakaryocytes-erythroid progenitors (CMP-MEP), granulocytes / macrophage progenitors (GMP), and pre-B / NK progenitors (preBNK). From left to right in each group of FIG. 30, BaEVTR, BaEVX-1, BaEVX-2, and saline. LT = Long-Term humanization (Week 11) BNK = PreB / NK progenitors. MEP = Megakaryocytes-Erythroid Progenitors. CMP = Common Myeloid Progenitors. GMP = Granulocytes / Macrophage Progenitors.

[0117] FIGs. 31A-31C depict the amino acid sequences and residue positions of cut sites within the envelope protein surface units.WSGR Docket No.: 62697-751.601

[0118] FIGs. 32A-32B show the editing efficiency of B2M in HEK293T cells (FIG. 32A) and Hematopoietic Stem and Progenitor Cells (HSPCs; FIG. 32B) transduced with the following chimeric BaEV-FeLV eVLPs: 1) Standard BaEV-FeLV eVLPs, 2) BaEV- FeLV eVLPs with Gag-MLV-Pro, 3) BaEV- FeLV eVLPs with Gag-MLV-Pro and MLV protease cleavage site (PR / RT), 4) BaEV- FeLV eVLPs with Gag-MLV-Pro and MLV protease cleavage site (RT / IN), 5) BaEV- FeLV eVLPs with Gag- HlV-Pro and HIV protease cleavage site (RT / IN), 6) BaEV- FeLV eVLPs with Gag-HIV-Pro and HIV protease cleavage site (CA / NC), or 7) BaEV- FeLV with Gag-HIV-Pro. Each figure shows dose responses in HEK293T cells (FIG. 32A) and HSPCs (FIG. 32B).

[0119] FIGs. 33A-33D show the in vivo editing efficiency in Lineage-negative (Lin-) (FIG. 33A), Lineage-positive (Lin+) (FIG. 33B), and NGS (FIG. 33C) Hematopoietic Stem Cells (HSCs) in a mice model transduced using BaEV-FeLV eVLPs containing an ABE base editor targeting the B2M gene and comprising standard delivery particles without CC (FeLV-ABE-B2M), standard coiled-coil (FeLV-ABE- B2M-C-C), or the coiled-coil Pro (FeLV-ABE-C-C-Pro). Editing efficiency was measured as percentage of B2M negative targets (% B2M negative). FIG. 33D shows the production volume for each BaEV- FeLV eVLP tested.DETAILED DESCRIPTION

[0120] Provided herein, in some embodiments, is a lipid delivery particle comprising a chimeric envelope protein. In some embodiments, the chimeric envelope protein comprises a surface unit, a cytoplasmic domain, and a R peptide. The retroviral envelope glycoprotein is encoded by the env gene. The retroviral env gene can be expressed as two subunits, surface (SU) and transmembrane (TM), which can form an retroviral envelope protein (also known as a retroviral glycoprotein). SU can mediate receptor binding. TM can mediate membrane fusion. The TM has a cytoplasmic tail referred to as R peptide. The R peptide on TM can inhibit fusion during budding. During retroviral replication cycle, upon viral particle maturation, the R peptide can be cleaved by retroviral protease. In some embodiments of the present disclosure, the R peptide of the envelope protein of the lipid delivery particle is not an MLV envelope protein R peptide. In some embodiments, the cytoplasmic domain of the envelope protein of the lipid delivery particle is not an MLV envelope protein cytoplasmic domain.

[0121] In some embodiments, the surface unit and the cytoplasmic domain are derived from different species of virus. In some embodiments, the surface unit and the R peptide are derived from different species of virus. In some embodiments, the cytoplasmic domain and the R peptide are derived from different species of virus. In some embodiments, the surface unit and the cytoplasmic domain are derived from the same species of virus. In some embodiments, the surface unit and the R peptide are derived from the same species of virus. In some embodiments, the cytoplasmic domain and the R peptide are derived from the same species of virus. In some embodiments, the R peptide is cleavable by a protease. In some embodiments, the protease is a retroviral protease. In some embodiments, the protease is a MLV protease.DefinitionsWSGR Docket No.: 62697-751.601

[0122] As used in the present disclosure, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, the term "a chimeric transmembrane receptor polypeptide" includes a plurality of chimeric transmembrane receptor polypeptides.

[0123] The term "about" or "approximately" means within an acceptable error range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, "about" can mean within 1 or more than 1 standard deviation, per the practice in the art. Alternatively, "about" can mean a range of up to 20%, up to 10%, up to 5%, or up to 1% of a given value. Alternatively, particularly with respect to biological systems or processes, the term can mean within an order of magnitude, preferably within 5-fold, and more preferably within 2-fold, of a value. Where particular values are described in the application, unless otherwise stated, the term "about" meaning within an acceptable error range for the particular value should be assumed.

[0124] As used herein, a "cell" can generally refer to a biological cell. A cell can be the basic structural, functional and / or biological unit of a living organism. A cell can originate from any organism having one or more cells. Some examples include: a prokaryotic cell, eukaryotic cell, a bacterial cell, an archaeal cell, a cell of a single-cell eukaryotic organism, a protozoa cell, a cell from a plant (e.g., cells from plant crops, fruits, vegetables, grains, soy bean, com, maize, wheat, seeds, tomatoes, rice, cassava, sugarcane, pumpkin, hay, potatoes, cotton, cannabis, tobacco, flowering plants, conifers, gymnosperms, fems, clubmosses, homworts, liverworts, mosses), an algal cell, (e.g., Botryococcus braunii, Chlamydomonas reinhardtii, Nannochloropsis gaditana, Chlorella pyrenoidosa, Sargassum patens C. Agardh, and the like), seaweeds (e.g., kelp), a fungal cell (e.g., a yeast cell, a cell from a mushroom), an animal cell, a cell from an invertebrate animal (e.g., fruit fly, cnidarian, echinoderm, nematode, etc.), a cell from a vertebrate animal (e.g., fish, amphibian, reptile, bird, mammal), a cell from a mammal (e.g., a pig, a cow, a goat, a sheep, a rodent, a rat, a mouse, a non-human primate, a human, etc.), and etcetera. Sometimes a cell is not originating from a natural organism (e.g., a cell can be a synthetically made, sometimes termed an artificial cell).

[0125] The term "antibody," as used herein, refers to a proteinaceous binding molecule with immunoglobulin-like functions. The term antibody includes antibodies (e.g., monoclonal and polyclonal antibodies), as well as derivatives, variants, and fragments thereof. Antibodies include immunoglobulins (Ig's) of different classes (i.e. IgA, IgG, IgM, IgD and IgE) and subclasses (such as IgGl, IgG2, etc.). A derivative, variant or fragment thereof can refer to a functional derivative or fragment which retains the binding specificity (e.g., complete and / or partial) of the corresponding antibody. Antigen-binding fragments include Fab, Fab', F(ab')2, variable fragment (Fv), single chain variable fragment (scFv), minibodies, diabodies, and single-domain antibodies ("sdAb" or "nanobodies" or "camelids"). The term antibody includes antibodies and antigen-binding fragments of antibodies that have been optimized, engineered or chemically conjugated. Examples of antibodies that have been optimized include affinity- matured antibodies. Examples of antibodies that have been engineered include Fc optimized antibodiesWSGR Docket No.: 62697-751.601(e.g., antibodies optimized in the fragment crystallizable region) and multispecific antibodies (e.g., bispecific antibodies).

[0126] The term "nucleotide," as used herein, generally refers to a base-sugar-phosphate combination. A nucleotide can comprise a synthetic nucleotide. A nucleotide can comprise a synthetic nucleotide analog. Nucleotides can be monomeric units of a nucleic acid sequence (e.g. deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)). The term nucleotide can include ribonucleoside triphosphates adenosine triphosphate (ATP), uridine triphosphate (UTP), cytosine triphosphate (CTP), guanosine triphosphate (GTP) and deoxyribonucleoside triphosphates such as dATP, dCTP, diTP, dUTP, dGTP, dTTP, or derivatives thereof. Such derivatives can include, for example, [aS]dATP, 7-deaza-dGTP and 7-deaza- dATP, and nucleotide derivatives that confer nuclease resistance on the nucleic acid molecule containing them. The term nucleotide as used herein can refer to dideoxyribonucleoside triphosphates (ddNTPs) and their derivatives. Illustrative examples of dideoxyribonucleoside triphosphates can include ddATP, ddCTP, ddGTP, ddITP, and ddTTP.

[0127] The terms "polynucleotide," "oligonucleotide," "nucleic acid", and "nucleic acid molecule" are used interchangeably to refer to a polymeric form of nucleotides of any length, either deoxyribonucleotides or ribonucleotides, or analogs thereof, either in single-, double-, or multi-stranded form. A polynucleotide can be exogenous or endogenous to a cell. A polynucleotide can exist in a cell- free environment. A polynucleotide can be a gene or fragment thereof. A polynucleotide can be DNA. A polynucleotide can be RNA. A polynucleotide can have any three-dimensional structure, and can perform any function, known or unknown. A polynucleotide can comprise one or more analogs (e.g. altered backbone, sugar, or nucleobase). If present, modifications to the nucleotide structure can be imparted before or after assembly of the polymer. Some examples of analogs include: 5 -bromouracil, peptide nucleic acid, xeno nucleic acid, morpholines, locked nucleic acids, glycol nucleic acids, threose nucleic acids, dideoxynucleotides, cordycepin, 7-deaza-GTP, fluorophores (e.g. rhodamine or fluorescein linked to the sugar), thiol containing nucleotides, biotin linked nucleotides, fluorescent base analogs, CpG islands, methyl-7-guanosine, methylated nucleotides, inosine, thiouridine, pseudourdine, dihydrouridine, queuosine, and wyosine. Examples of polynucleotides include coding or non-coding regions of a gene or gene fragment, loci (locus) defined from linkage analysis, exons, introns, messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), short interfering RNA (siRNA), short-hairpin RNA (shRNA), micro-RNA (miRNA), ribozymes, cDNA, recombinant polynucleotides, branched polynucleotides, plasmids, vectors, isolated DNA of any sequence, isolated RNA of any sequence, cell- free polynucleotides including cell-free DNA (cfDNA) and cell-free RNA (cfRNA), nucleic acid probes, and primers. The sequence of nucleotides can be interrupted by non-nucleotide components.

[0128] The term "gene," as used herein, refers to a nucleic acid (e.g., DNA such as genomic DNA and cDNA) and its corresponding nucleotide sequence that is involved in encoding an RNA transcript. The term as used herein with reference to genomic DNA includes intervening, non-coding regions as well as regulatory regions and can include 5' and 3' ends. In some uses, the term encompasses the transcribed sequences, including 5' and 3' untranslated regions (5'-UTR and 3'-UTR), exons and introns. In someWSGR Docket No.: 62697-751.601 genes, the transcribed region will contain "open reading frames" that encode polypeptides. In some uses of the term, a "gene" comprises only the coding sequences (e.g., an "open reading frame" or "coding region") for encoding a polypeptide. In some cases, genes do not encode a polypeptide, for example, ribosomal RNA genes (rRNA) and transfer RNA (tRNA) genes. In some cases, the term "gene" includes not only the transcribed sequences, but in addition, also includes non-transcribed regions including upstream and downstream regulatory regions, enhancers and promoters. A gene can refer to an "endogenous gene" or a native gene in its natural location in the genome of an organism. A gene can refer to an "exogenous gene" or a non-native gene. A non-native gene can refer to a gene not normally found in the host organism, but which is introduced into the host organism by gene transfer. A non-native gene can also refer to a gene not in its natural location in the genome of an organism. A non-native gene can also refer to a naturally occurring nucleic acid or polypeptide sequence that comprises mutations, insertions and / or deletions (e.g., non-native sequence).

[0129] The terms "target polynucleotide," "target nucleic acid," and "target sequence," as used herein, refer to a nucleic acid or polynucleotide which is targeted by a payload of the present disclosure. A target polynucleotide can be DNA (e.g., endogenous or exogenous). DNA can refer to template to generate mRNA transcripts and / or the various regulatory regions which regulate transcription of mRNA from a DNA template. A target polynucleotide can be a portion of a larger polynucleotide, for example a chromosome or a region of a chromosome. A target polynucleotide can refer to an extrachromosomal sequence (e.g., an episomal sequence, a minicircle sequence, a mitochondrial sequence, a chloroplast sequence, etc.) or a region of an extrachromosomal sequence. A target polynucleotide can be RNA. RNA can be, for example, mRNA which can serve as template encoding for proteins. A target polynucleotide comprising RNA can include the various regulatory regions which regulate translation of protein from an mRNA template. A target polynucleotide can encode for a gene product (e.g., DNA encoding for an RNA transcript or RNA encoding for a protein product) or comprise a regulatory sequence which regulates expression of a gene product. In general, the term "target sequence" refers to a nucleic acid sequence on a single strand of a target nucleic acid. The target sequence can be a portion of a gene, a regulatory sequence, genomic DNA, cell free nucleic acid including cfDNA and / or cfRNA, cDNA, a chimeric gene, and RNA including mRNA, miRNA, rRNA, and others. A target polynucleotide, when targeted by a payload, can result in altered gene expression and / or activity. A target polynucleotide, when targeted by a payload, can result in an edited nucleic acid sequence. A target nucleic acid can comprise a nucleic acid sequence that may not be related to any other sequence in a nucleic acid sample by a single nucleotide substitution. A target nucleic acid can comprise a nucleic acid sequence that may not be related to any other sequence in a nucleic acid sample by a 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide substitutions. In some embodiments, the substitution does not occur within 5, 10, 15, 20, 25, 30, or 35 nucleotides of the 5' end of a target nucleic acid. In some embodiments, the substitution does not occur within 5, 10, 15, 20, 25, 30, 35 nucleotides of the 3' end of a target nucleic acid.

[0130] The term "expression" refers to one or more processes by which a polynucleotide is transcribed from a DNA template (such as into an mRNA or other RNA transcript) and / or the process by which aWSGR Docket No.: 62697-751.601 transcribed mRNA is subsequently translated into peptides, polypeptides, or proteins. Transcripts and encoded polypeptides can be collectively referred to as "gene product." If the polynucleotide is derived from genomic DNA, expression can include splicing of the mRNA in a eukaryotic cell. "Up-regulated," with reference to expression, generally refers to an increased expression level of a polynucleotide (e.g., RNA such as mRNA) and / or polypeptide sequence relative to its expression level in a wild type state while "down-regulated" generally refers to a decreased expression level of a polynucleotide (e.g., RNA such as mRNA) and / or polypeptide sequence relative to its expression in a wild type state.

[0131] The terms "complement," "complements," "complementary," and "complementarity," as used herein, generally refer to a sequence that is fully complementary to and hybridizable to the given sequence. In some cases, a sequence hybridized with a given nucleic acid is referred to as the "complement" or "reverse-complement" of the given molecule if its sequence of bases over a given region is capable of complementarily binding those of its binding partner, such that, for example, A-T, AU, G-C, and G-U base pairs are formed. In general, a first sequence that is hybridizable to a second sequence is specifically or selectively hybridizable to the second sequence, such that hybridization to the second sequence or set of second sequences is preferred (e.g. thermodynamically more stable under a given set of conditions, such as stringent conditions commonly used in the art) to hybridization with non-target sequences during a hybridization reaction. Hybridizable sequences can share a degree of sequence complementarity over all or a portion of their respective lengths, such as between 25%-100% complementarity, including at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, and 100% sequence complementarity. Sequence identity, such as for the purpose of assessing percent complementarity, can be measured by any suitable alignment algorithm, including the Needleman-Wunsch algorithm (see e.g. the EMBOSS Needle aligner available at www.ebi.ac.uk / Tools / psa / emboss_needle / nucleotide.html, optionally with default settings), the BEAST algorithm (see e.g. the BLAST alignment tool available at blast.ncbi.nlm.nih.gov / Blast.cgi, optionally with default settings), or the Smith-Waterman algorithm (see e.g. the EMBOSS Water aligner available at www.ebi.ac.uk / Tools / psa / emboss_water / nucleotide.html, optionally with default settings). Optimal alignment can be assessed using any suitable parameters of a chosen algorithm, including default parameters.

[0132] Complementarity can be perfect or substantial / sufficient. Perfect complementarity between two nucleic acids can mean that the two nucleic acids can form a duplex in which every base in the duplex is bonded to a complementary base by Watson-Crick pairing. Substantial or sufficient complementary can mean that a sequence in one strand is not completely and / or perfectly complementary to a sequence in an opposing strand, but that sufficient bonding occurs between bases on the two strands to form a stable hybrid complex in set of hybridization conditions (e.g., salt concentration and temperature). Such conditions can be predicted by using the sequences and standard mathematical calculations to predict the Tm of hybridized strands, or by empirical determination of Tm by using routine methods.WSGR Docket No.: 62697-751.601

[0133] The term "regulating" with reference to expression or activity, as used herein, refers to altering the level of expression or activity. Regulation can occur at the transcriptional level, post-transcriptional level, translational level, and / or post-translational level.

[0134] The terms "peptide," "polypeptide," and "protein" are used interchangeably herein to refer to a polymer of at least two amino acid residues joined by peptide bond(s). This term does not connote a specific length of polymer, nor is it intended to imply or distinguish whether the peptide is produced using recombinant techniques, chemical or enzymatic synthesis, or is naturally occurring. The terms apply to naturally occurring amino acid polymers as well as amino acid polymers comprising at least one modified amino acid. In some cases, the polymer can be interrupted by non-amino acids. The terms include amino acid chains of any length, including full length proteins, and proteins with or without secondary and / or tertiary structure (e.g., domains). The terms also encompass an amino acid polymer that has been modified, for example, by disulfide bond formation, glycosylation, lipidation, acetylation, phosphorylation, oxidation, and any other manipulation such as conjugation with a labeling component. The terms "amino acid" and "amino acids," as used herein, generally refer to natural and non-natural amino acids, including modified amino acids and amino acid analogues. Modified amino acids can include natural amino acids and non-natural amino acids, which have been chemically modified to include a group or a chemical moiety not naturally present on the amino acid. Amino acid analogues can refer to amino acid derivatives. The term "amino acid" includes both D-amino acids and L-amino acids.

[0135] The term "variant," when used herein with reference to a polypeptide, refers to a polypeptide related, but not identical, to a wild type polypeptide, for example either by amino acid sequence, structure (e.g., secondary and / or tertiary), activity (e.g., enzymatic activity) and / or function. Variants include polypeptides comprising one or more amino acid variations (e.g., mutations, insertions, and deletions), truncations, modifications, or combinations thereof compared to a wild type polypeptide. Variants also include derivatives of the wild type polypeptide and fragments of the wild type polypeptide.

[0136] The term "percent (%) identity," as used herein, refers to the percentage of amino acid (or nucleic acid) residues of a candidate sequence that are identical to the amino acid (or nucleic acid) residues of a reference sequence after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent identity (i.e., gaps can be introduced in one or both of the candidate and reference sequences for optimal alignment and non-homologous sequences can be disregarded for comparison purposes). Alignment, for purposes of determining percent identity, can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, ALIGN, or Megalign (DNASTAR) software. Percent identity of two sequences can be calculated by aligning a test sequence with a comparison sequence using BLAST, determining the number of amino acids or nucleotides in the aligned test sequence that are identical to amino acids or nucleotides in the same position of the comparison sequence, and dividing the number of identical amino acids or nucleotides by the number of amino acids or nucleotides in the comparison sequence.

[0137] A Cas protein referred to herein can be a type of protein or polypeptide. A Cas protein can refer to a nuclease. A Cas protein can refer to an endoribonuclease. A Cas protein can refer to any modifiedWSGR Docket No.: 62697-751.601(e.g., shortened, mutated, lengthened) polypeptide sequence or homologue of the Cas protein. A Cas protein can be codon optimized. A Cas protein can be a codon-optimized homologue of a Cas protein. A Cas protein can be enzymatically inactive, partially active, constitutively active, fully active, inducible active and / or more active, (e.g. more than the wild type homologue of the protein or polypeptide.). A Cas protein can be a Type II Cas protein. A Cas protein can be Cas9. A Cas protein can be a Type V Cas protein. A Cas protein can be Cpfl or Cas 12a. A Cas protein can be C2cl. A Cas protein can be C2c3. A Cas protein can be a Type VI Cas protein. A Cas protein can be C2c2 or Cas 13a. A Cas protein can be Casl3b. A Cas protein can be Casl3c. A Cas protein can be Casl3d. A Cas protein can be Casl4. A Cas protein (e.g., variant, mutated, enzymatically inactive and / or conditionally enzymatically inactive site- directed polypeptide) can bind to a target nucleic acid. A Cas protein (e.g., variant, mutated, enzymatically inactive and / or conditionally enzymatically inactive endoribonuclease) can bind to a target RNA or DNA.

[0138] The term "crRNA," as used herein, can generally refer to a nucleic acid with at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% sequence identity and / or sequence similarity to a wild type exemplary crRNA (e.g., a crRNA from .S', pyogenes). crRNA can generally refer to a nucleic acid with at most about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% sequence identity and / or sequence similarity to a wild type exemplary crRNA (e.g., a crRNA from .S'. pyogenes, S. aureus, etc). crRNA can refer to a modified form of a crRNA that can comprise a nucleotide change such as a deletion, insertion, or substitution, variant, mutation, or chimera. A crRNA can be a nucleic acid having at least about 60% sequence identity to a wild type exemplary crRNA (e.g., a crRNA from .S', pyogenes, S. aureus, etc) sequence over a stretch of at least 6 contiguous nucleotides. For example, a crRNA sequence can be at least about 60% identical, at least about 65% identical, at least about 70% identical, at least about 75% identical, at least about 80% identical, at least about 85% identical, at least about 90% identical, at least about 95% identical, at least about 98% identical, at least about 99% identical, or 100 % identical to a wild type exemplary crRNA sequence (e.g., a crRNA from .S'. pyogenes, S. aureus, etc) over a stretch of at least 6 contiguous nucleotides.

[0139] The term "tracrRNA," as used herein, can generally refer to a nucleic acid with at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% sequence identity and / or sequence similarity to a wild type exemplary tracrRNA sequence (e.g., a tracrRNA from .S', pyogenes). tracrRNA can refer to a nucleic acid with at most about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% sequence identity and / or sequence similarity to a wild type exemplary tracrRNA sequence (e.g., a tracrRNA from .S', pyogenes, S. aureus, etc). tracrRNA can refer to a modified form of a tracrRNA that can comprise a nucleotide change such as a deletion, insertion, or substitution, variant, mutation, or chimera. A tracrRNA can refer to a nucleic acid that can be at least about 60% identical to a wild type exemplary tracrRNA (e.g., a tracrRNA from .S', pyogenes, S. aureus, etc) sequence over a stretch of at least 6 contiguous nucleotides. For example, a tracrRNA sequence can be at least about 60% identical, at least about 65% identical, at least about 70% identical, at least about 75% identical, at least about 80% identical, at least about 85% identical, at least about 90% identical, at least about 95% identical, at leastWSGR Docket No.: 62697-751.601 about 98% identical, at least about 99% identical, or 100 % identical to a wild type exemplary tracrRNA (e.g., a tracrRNA from .S' pyogenes, S. aureus, etc.) sequence over a stretch of at least 6 contiguous nucleotides.

[0140] As used herein, a "guide nucleic acid" can refer to a nucleic acid that can hybridize to another nucleic acid. A guide nucleic acid can be RNA. A guide nucleic acid can be DNA. The guide nucleic acid can be programmed to bind to a sequence of nucleic acid site-specifically. The nucleic acid to be targeted, or the target nucleic acid, can comprise nucleotides. The guide nucleic acid can comprise nucleotides. A portion of the target nucleic acid can be complementary to a portion of the guide nucleic acid. The strand of a double-stranded target polynucleotide that is complementary to and hybridizes with the guide nucleic acid can be called the complementary strand. The strand of the double-stranded target polynucleotide that is complementary to the complementary strand, and therefore may not be complementary to the guide nucleic acid can be called noncomplementary strand. A guide nucleic acid can comprise a polynucleotide chain and can be called a "single guide nucleic acid." A single guide nucleic acid can comprise a crRNA. A single guide nucleic acid can comprise a crRNA and a tracrRNA. A guide nucleic acid can comprise two polynucleotide chains and can be called a "double guide nucleic acid." A double guide nucleic acid can comprise a crRNA and a tracrRNA. If not otherwise specified, the term "guide nucleic acid" can be inclusive, referring to both single guide nucleic acids and double guide nucleic acids.

[0141] A guide nucleic acid can comprise a segment that can be referred to as a "nucleic acid-targeting segment" or a "nucleic acid-targeting sequence." A nucleic acid -targeting segment can comprise a subsegment that can be referred to as a "protein binding segment" or "protein binding sequence" or "Cas protein binding segment".

[0142] The term "targeting sequence," as used herein, refers to a nucleotide sequence and the corresponding amino acid sequence which encodes a targeting polypeptide which mediates the localization (or retention) of a protein to a sub-cellular location, e.g., plasma membrane or membrane of a given organelle, nucleus, cytosol, mitochondria, endoplasmic reticulum (ER), Golgi, chloroplast, apoplast, peroxisome or another organelle. For example, a targeting sequence can direct a protein (e.g., a receptor polypeptide or an adaptor polypeptide) to a nucleus utilizing a nuclear localization signal (NLS); outside of a nucleus of a cell, for example to the cytoplasm, utilizing a nuclear export signal (NES); mitochondria utilizing a mitochondrial targeting signal; the endoplasmic reticulum (ER) utilizing an ER- retention signal; a peroxisome utilizing a peroxisomal targeting signal; plasma membrane utilizing a membrane localization signal; or combinations thereof.

[0143] As used herein, "nuclear localization domain" can refer to a nuclear localization signal or other sequence or domain capable of traversing a nuclear membrane, thereby entering the nucleus. A nuclear localization domain can be fused in-frame with a polypeptide, in which case the nuclear localization domain can be referred to as a "heterologous nuclear localization domain."

[0144] As used herein, "nuclear export domain" can refer to a nuclear export signal or other sequence or domain that is present in a protein and capable of targeting the protein for export from the cell nucleus to the cytoplasm through the nuclear pore complex using nuclear transport. A nuclear export domain can beWSGR Docket No.: 62697-751.601 fused in-frame with a polypeptide, in which case the nuclear export domain can be referred to as a "heterologous nuclear export domain."

[0145] As used herein, "fusion" or "chimera" can refer to a protein and / or nucleic acid comprising one or more non-native sequences (e.g., moieties). A chimera or fusion can comprise one or more of the same non-native sequences. A chimera or fusion can comprise one or more of different non-native sequences. A chimera or fusion can be a chimera. A chimera or fusion can comprise a nucleic acid affinity tag. A chimera or fusion can comprise a barcode. A fusion can comprise a peptide affinity tag. A chimera or fusion can provide for subcellular localization of the site-directed polypeptide (e.g., a nuclear localization signal (NLS) for targeting to the nucleus, a mitochondrial localization signal for targeting to the mitochondria, a chloroplast localization signal for targeting to a chloroplast, an endoplasmic reticulum (ER) retention signal, and the like). A chimera or fusion can provide a non-native sequence (e.g., affinity tag) that can be used to track or purify.

[0146] A fusion or chimera can refer to any protein with a functional effect. For example, a chimeric protein can comprise methyltransferase activity, demethylase activity, dismutase activity, alkylation activity, depurination activity, oxidation activity, pyrimidine dimer forming activity, integrase activity, transposase activity, recombinase activity, polymerase activity, ligase activity, helicase activity, photolyase activity or glycosylase activity, acetyltransferase activity, deacetylase activity, kinase activity, phosphatase activity, ubiquitin ligase activity, deubiquitinating activity, adenylation activity, deadenylation activity, SUMOylating activity, deSUMOylating activity, ribosylation activity, deribosylation activity, myristoylation activity, remodeling activity, protease activity, oxidoreductase activity, transferase activity, hydrolase activity, lyase activity, isomerase activity, synthase activity, synthetase activity, or demyristoylation activity. An effector protein can modify a genomic locus.

[0147] As used herein, "non-native" can refer to a nucleic acid or polypeptide sequence that is not found in a native nucleic acid or protein. Non-native can refer to affinity tags. Non-native can refer to chimeras or fusions, e.g., chimeric proteins or chimeric nucleic acids. Non-native can refer to a naturally occurring nucleic acid or polypeptide sequence that comprises mutations, insertions and / or deletions. A non-native sequence can exhibit and / or encode for an activity (e.g., enzymatic activity, methyltransferase activity, acetyltransferase activity, kinase activity, ubiquitinating activity, etc.) that can also be exhibited by the nucleic acid and / or polypeptide sequence to which the non-native sequence is fused. A non-native nucleic acid or polypeptide sequence can be linked to a naturally-occurring nucleic acid or polypeptide sequence (or a variant thereof) by genetic engineering to generate a chimeric nucleic acid and / or polypeptide sequence encoding a chimeric nucleic acid and / or polypeptide.

[0148] The terms "subject," "individual," and "patient" are used interchangeably herein to refer to a vertebrate, preferably a mammal such as a human. Mammals include murines, simians, humans, farm animals, sport animals, and pets. Tissues, cells and their progeny of a biological entity obtained in vivo or cultured in vitro are also encompassed.

[0149] The terms "treatment" and "treating," as used herein, refer to an approach for obtaining beneficial or desired results including a therapeutic benefit and / or a prophylactic benefit. For example, a treatmentWSGR Docket No.: 62697-751.601 can comprise administering a system or cell population disclosed herein. By therapeutic benefit is meant any therapeutically relevant improvement in or effect on one or more diseases, conditions, or symptoms under treatment. For prophylactic benefit, a composition can be administered to a subject at risk of developing a particular disease, condition, or symptom, or to a subject reporting one or more of the physiological symptoms of a disease, even though the disease, condition, or symptom may not have yet been manifested.

[0150] The term "effective amount" or "therapeutically effective amount" are used interchangeably herein, and refer to an amount of a compound, formulation, material, or composition, as described herein effective to achieve a particular biological or therapeutic result. As used herein, the term "recombinase," refers to a site-specific enzyme that can mediate the recombination of DNA between recombinase recognition sequences. It can cause DNA excision, integration, inversion, or exchange, such as translocation between two recombinase recognition sequences.

[0151] The term "recombine," or "recombination," is used herein in the context of a nucleic acid modification (e.g., a genomic modification) to refer to the process by which two or more nucleic acid molecules, or two or more regions of a single nucleic acid molecule, are modified by the action of a protein, e.g., a recombinase. Recombination can result in insertion, inversion, excision, or translocation of nucleic acids, e.g., in or between one or more nucleic acid molecules.PROTEIN CORE

[0152] In some cases, the lipid delivery particle disclosed herein comprises a protein core that is composed of at least a structural protein of a viral origin, for instance, a retroviral gag protein. In some of these cases, the lipid delivery particle comprises a retroviral gag-pro-pol polyprotein, e.g., a gag-pro-pol poly protein from HIV, MLV (e.g., MMLV, or Friend murine leukemia virus (FMLV)), which can help assemble a protein core of the lipid delivery particle. In some of these cases, some of the gag-pro-pol polyprotein is cleaved, e.g., by pro (protease) present freely or in the gag-pro-pol polyprotein. Without wishing to be bound by any particular theory, the cleavage by pro can be inefficient, and the resultant cleavage products can include gag polyprotein, gag -pro polyprotein, free pro, and free pol (polymerase). In some cases, a retroviral gag polyprotein can be further cleaved into MA, CA, NC, and other small fragments, if any. In some other cases, the lipid delivery particle comprises a retroviral gag-pro polyprotein without the pol component, and the gag-pro polyprotein can help form a protein core of the lipid delivery particle. The gag-pro can also be cleaved by pro, in some cases, inefficiently, into separate gag and pro proteins. In some cases, there can be different plasma membrane recruitment elements in a lipid delivery particle. For instance, a gag-pro or gag-pro-pol polyprotein from one species of virus (e.g., a retrovirus, e.g., a HIV) can help assemble form a protein core of the lipid delivery particle, while a chimeric protein in the lipid delivery particle, discussed infra, can comprise a payload fused with a gag protein from a different species of virus (e.g., an MMLV), or from a HERV, or a PH domain or transmembrane domain of a huma protein (e.g., a PH domain of human Akl with E17K substitution).

[0153] In some embodiments, the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murineWSGR Docket No.: 62697-751.601 leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (Re EV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

[0154] In some embodiments, the gag-pro polyprotein is a gag-pro polyprotein from human immunodeficiency virus (HIV), murine leukemia virus (MLV) (e.g., MMLV, or FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.ENVELOPE PROTEIN

[0155] In some aspects, the lipid delivery particle provided herein comprises an envelope protein. The envelope protein can be associated with the outside boundary or the surface of the lipid delivery particle, for example, the membrane or envelope of the lipid delivery particle.

[0156] The membrane of the lipid delivery particle can comprise a lipid layer, such as a single layer or a lipid bilayer. In some cases, the membrane of the lipid delivery particle is from plasma membrane, endoplasmic reticulum, or a combination thereof. In some cases, the membrane of the lipid delivery particle is from Golgi complex, ER Golgi intermediate compartment, or nuclear envelope. In some cases, the membrane of the lipid delivery particle is from plasma membrane. In some cases, the membrane of the lipid delivery particle is a phospholipid bilayer.

[0157] The envelope protein can be associated with the membrane of the lipid delivery particle in various manners. For example, the envelope protein can be anchored or attached to the external membrane of the particle or anchored or attached to the internal membrane of the particle. The envelope protein can be embedded or inserted in the membrane, spanning through the membrane, with certain portions located at the outside of the membrane, or certain portions extending to the inside of the particle, or both. The envelope protein within the lipid delivery particle described herein can be overexpressed from an exogenous source, such as plasmids or stably integrated transgenes, in the production cells.

[0158] The envelope protein can play a role in the delivery of the lipid delivery particle to a target cell and release of the components of the lipid delivery particle within the target cell. The envelope protein can contact with the surface of a target cell and participate in the fusion of the lipid delivery particle and the membrane of the target cell. The envelope protein can participate in the fusion of the lipid delivery particle with the membrane of the target cell via any appropriate mechanism, such as those described in White et al. Crit Rev Biochem Mol Biol. 2008; 43(3): 189-219. One example of the fusion mechanisms is unifying Trimer-of-Hairpins Fusion Mechanism. Membrane fusion can occur after allosteric priming by binding to a target receptor. In some cases, membrane fusion occurs after proteolysis. In some cases, membrane fusion occurs after isomerization of disulfide bridges. In some cases, membrane fusion occursWSGR Docket No.: 62697-751.601 by internalization and then priming of fusion via (i) cathepsin-mediated proteolysis, or (ii) low pH / acidification. The cathepsin-mediated proteolysis can be pH dependent or pH independent. Other fusion triggering mechanisms can include low PH, binding to target cell receptors, and a receptor followed by low pH. The envelope protein can also play a role in the formation of the lipid delivery particle. The envelope protein can interact with another component within the lipid delivery particle and participate in the assembly of the lipid delivery particle, for example, in a producer cell. The envelope protein can make contact with another envelope protein and form an oligomer embedded within the membrane. The envelope protein can be a glycoprotein, for example, a transmembrane glycoprotein. In some cases, envelope protein comprises multiple membrane-spanning regions. These multiple membranespanning regions can oligomerize and form channels in the membrane.

[0159] In some cases, the envelope protein is fused with a targeting moiety. In some cases, the targeting moiety recognizes a specific molecule (e.g., antigen, receptor, or other membrane protein) on the surface of a target cell to allow targeted cell entry with more specificity. In some cases, the targeting moiety is specific for a certain cell type or is specific for a certain target cell. In some cases, the specific molecule is CD 133. In some cases, the specific molecule is C7 or AC 133. The targeting moiety can be fused to the envelope protein at a position that is located at an outside of the lipid delivery particle. For example, the targeting moiety includes scFvs, antibody variable regions, nanobodies, T-cell receptor variable regions, other antigen-binding fragments or their mimetics, such as DARPins. In some cases, the targeting moiety is a protein ligand from the human ligandome. The targeting moiety can be a natural peptide or a synthetic peptide. In some cases, the targeting moiety is not fused with the envelope protein and is attached to the membrane of the lipid delivery particle from the outside, for example, via a transmembrane domain.

[0160] A targeting moiety can include, e.g., an antibody or an antigen-binding fragment thereof (e.g., Fab, Fab', F(ab')2, Fv fragments, scFv antibody fragments, disulfide-linked Fvs (sdFv), a Fd fragment consisting of the VH and CHI domains, linear antibodies, single domain antibodies such as sdAb (either VL or VH), nanobodies, or camelid VHH domains), an antigen-binding fibronectin type III (Fn3) scaffold such as a fibronectin polypeptide minibody, a ligand, a cytokine, a chemokine, or a T cell receptor (TCRs). Membrane-fusion proteins can be re-targeted by non-covalently conjugating a targeting moiety to the membrane -fusion protein or targeting protein (e.g. the hemagglutinin protein). For example, the membrane -fusion protein can be engineered to bind the Fc region of an antibody that targets an antigen on a target cell, redirecting the membrane fusion activity towards cells that display the antibody’s target.

[0161] In some cases, the targeting moiety linked to the membrane-fusion protein binds a cell surface marker on the target cell, e.g., a protein, glycoprotein, receptor, cell surface ligand, agonist, lipid, sugar, class I transmembrane protein, class II transmembrane protein, or class III transmembrane protein.

[0162] In some cases, the lipid delivery particles disclosed herein display targeting moieties that are not conjugated to the membrane -fusion protein or other proteins in order to redirect the fusion activity of the lipid delivery particle towards a cell that is bound by the targeting moiety, or to affect tropism of the lipid delivery particle toward the target cell.WSGR Docket No.: 62697-751.601Coiled-coil

[0163] In some aspects, the lipid delivery particles described herein may comprise a coiled-coil peptide pair, such as E4 / K4 coiled-coil peptides. In some aspects of the present disclosure, the lipid delivery particle utilizes coiled-coil peptide interaction to package / load payload into the particle. Coiled-coil (CC) peptides are small peptides that can tether together like Velcro. They can be attracted to each other due to hydrophobic effect and the interaction is stabilized by electrostatic interactions, causing two alpha helical domains to wind around each other.

[0164] In some aspects of the present disclosure, a lipid delivery particle provided herein comprises a first chimeric protein, e.g., a first coiled-coil peptide fused with a plasma membrane recruitment element, and a second chimeric protein comprising a second coiled-coil peptide fused with a payload protein, and the first coiled-coil peptide and the second coiled-coil peptide form a coiled-coil peptide pair in that they can be attracted to each other. In such configuration, the payload protein can thus be packaged into the lipid delivery particle via the interaction of the second coiled-coil peptide and the first coiled-coil peptide that is fused with the plasma membrane recruitment element. In some such embodiments, the first chimeric protein and / or the second chimeric protein comprise a cleavable linker as disclosed herein. In some cases, the first coiled-coil peptide is fused to the C-terminus of the plasma membrane recruitment element. In some cases, the first coiled-coil peptide is fused to the N-terminus of the plasma membrane recruitment element. In some cases, the second coiled-coil peptide is fused to the C-terminus of the payload protein. In some cases, the second coiled-coil peptide is fused to the N-terminus of the payload protein. In some aspects, the coiled-coil design used herein is E4-K4 design. Using an E4-K4 CC domain can improve loading compared to other domains. In some aspects, the coiled-coil pair design used is one of E4-K4, EE12RR345L-RR12EE345L, EE1234L-RR1234L, EE12345L-RR12345L, AcidPl -BasePl, P3(x3)-P4, SynZip2-SynZipl9, SynZip2-SynZipl, and N5-N6. Coiled-coil peptide pairs suitable for use in the context of the present disclosure are known in the art and any suitable coiled-coil peptides and peptide pairs can be used in some embodiments of this disclosure, including, without limitation the coiled-coil peptides and peptide pairs disclosed in U.S. Provisional Patent Application Nos. 63 / 730,837 filed December 11, 2024, and 63 / 805,885, filed May 14, 2025, each of which is incorporated herein by reference in their entirety.Envelope protein of viral origin

[0165] In some cases, an envelope protein has a viral origin. For example, a suitable envelope protein is from a DNA virus, an RNA virus, or a retrovirus. The envelope protein can be envelope protein from Herpesviruses, Avian sarcoma leukosis virus, Poxviruses, Hepadnaviruses, Asfarviridae, Flaviviruses, Alphaviruses, Togaviruses, Coronaviruses, Hepatitis D, Orthomyxoviruses, Rhabdovirus, Bunyaviruses, Filoviruses, Oncoretroviruses, lentiviruses, Spumaviruses. In some cases, envelope protein can be envelope protein from lentiviruses, for example, human immunodeficiency virus (HIV), simian immunodeficiency virus (SIV), feline immunodeficiency virus (FIV) and equine infectious anemia virus (EIAV). In some cases, an envelope protein is a fusion of two different envelope proteins, wherein eachWSGR Docket No.: 62697-751.601 comes from a different virus. Additional suitable envelope proteins that are from viral origins and their functions are described in White JM et al., Crit Rev Biochem Mol Biol. 2008 May-Jun;43(3): 189-219.

[0166] In some cases, the envelope protein is a vesicular stomatitis virus glycoprotein (VSVG) or a biologically active mutant thereof. A “biologically active mutant” disclosed herein in connection with a reference protein can refer to a mutant of the reference protein that remains displaying one or more biological activities that are of same nature as the reference protein, which are relevant to the context in which the reference protein is used in the lipid delivery particle disclosed herein, while the level of the one or more biological activities of the biologically active mutant can be either similar as or different than the reference protein. For instance, the biologically active mutant of a VSVG in the context of an envelope protein remains displaying the biological activities of an envelope protein, e.g., mediating membrane fusion, tropism of the lipid delivery particle toward a target cell, or both. Unless otherwise noted, a mutant as described in the present disclosure is equivalent to a biologically active mutant. In some cases, the envelope protein is a Human immunodeficiency virus GP160 or a biologically active mutant thereof. In some cases, the envelope protein is a modified Baboon Endogenous Retrovirus glycoprotein with its cytoplasmic domain swapped with cytoplasmic domain of MLV envelope protein (BaEVTR) or a biologically active mutant thereof. In some cases, the envelope protein is a modified Baboon Endogenous Retrovirus (BaEV-Rless) glycoprotein or a biologically active mutant thereof. In some cases, the envelope protein is the fusion protein of Vesicular stomatitis Indiana virus and Rabies virus Glycoproteins (FuG-E) or a biologically active mutant thereof. In some cases, the envelope protein pantropic murine leukemia virus envelope protein (MLV) or a biologically active mutant thereof. In some cases, the envelope protein is a modified Fusion protein of Vesicular stomatitis Indiana virus and Rabies virus Glycoproteins (FuG-E P440E) or a biologically active mutant thereof. In some cases, the envelope protein is an ecotropic Murine Leukemia Virus envelope protein (MLV ENV ecotropic) or a biologically active mutant thereof. In some cases, the envelope protein is an amphotrophic Murine Leukemia Virus envelope protein (MLV ENV amphotropic) or a biologically active mutant thereof. In some cases, the envelope protein is a Moloney murine leukemia virus envelope protein (MMLV) or a biologically active mutant thereof. In some cases, the envelope protein is a Moloney murine sarcoma virus envelope protein (MoMSVg) or a biologically active mutant thereof. In some cases, the envelope protein is a moloney murine leukemia virus 10A1 strain Glycoprotein (MLV 10A1) or a biologically active mutant thereof. In some cases, the envelope protein is a xenotropic murine leukemia virus envelope protein (MLV ENV xenotropic) or a biologically active mutant thereof. In some cases, the envelope protein is a xenotropic murine leukemia virus-related envelope protein (XMRV) or a biologically active mutant thereof. In some cases, the envelope protein is a Baculovirus envelope glycoprotein (GP64) or a biologically active mutant thereof. In some cases, the envelope protein is an endogenous feline virus envelope protein (RD114 ENV) or a biologically active mutant thereof. In some cases, the envelope protein is a mammalian endogenous retrovirus protein, or a biologically active mutant thereof. The mammalian endogenous retrovirus protein can be a koala retrovirus protein (KoRV) or a Jaagsiekte sheep retrovirus protein (enJSRV), or a biologically active mutant thereof.WSGR Docket No.: 62697-751.601

[0167] In some cases, the envelope protein is a simian endogenous type D retrovirus protein (RD-114) or a biologically active mutant thereof. In some cases, the envelope protein is a gibbon ape leukemia virus envelope protein (GALV) or a biologically active mutant thereof. In some cases, the envelope protein is a feline leukemia virus envelope protein (FLV) or a biologically active mutant thereof. In some cases, the envelope protein is a mouse mammary tumor virus envelope protein (MMTV) or a biologically active mutant thereof. In some cases, the envelope protein is an avian leukosis virus envelope protein or a biologically active mutant thereof. In some cases, the envelope protein is a rous sarcoma virus envelope protein or a biologically active mutant thereof.

[0168] In some cases, the envelope protein can direct the lipid delivery particles to fuse with a certain type of target cells rather than other cells. For example, based on the specific type of envelope protein associated with the membrane of the lipid delivery particle, the lipid delivery particle can preferentially target different cell types (i.e., tropisms of the lipid delivery particles), such as liver cells, ocular cells, nerve cells, lung cells, immune cells, muscle cells, and any other cell types of interest. For example, to fuse with a target liver cells, the envelope protein can be a glycoprotein from human hepatitis viruses or a biologically active mutant thereof, e.g., Hepatitis B virus (HBV) or hepatitis C virus (HCV), VSV-G glycoprotein or a biologically active mutant thereof, a Marburg virus glycoprotein or a biologically active mutant thereof, an Ebola virus glycoprotein or a biologically active mutant thereof. To fuse with a target muscle cell, for example, a skeletal muscle cell, the envelope protein can be a Ross River virus glycoprotein or a biologically active mutant thereof, or a VSV-G or a biologically active mutant thereof. To fuse with a target ocular cell, for example, a photoreceptor cell or a retinal cell, the envelope protein can be an Ebola virus glycoprotein or a biologically active mutant thereof, a Marburg virus glycoprotein or a biologically active mutant thereof, or a VSV-G or a biologically active mutant thereof. To fuse with a target immune cell, for example, CD8+ T cell, an HTLV-1 glycoprotein or a biologically active mutant thereof, or a VSV- G glycoprotein or a biologically active mutant thereof. To fuse with a target immune cell, for example, CD4+ T cell, the envelope protein can be a HIV-1 envelope or a biologically active mutant thereof, a HTLV-1 glycoprotein or a biologically active mutant thereof, or a VSV-G glycoprotein or a biologically active mutant thereof. To fuse with a target lung cells, the envelope protein can be a respiratory syncytial virus glycoprotein or a biologically active mutant thereof, or a SARS-CoV glycoprotein or a biologically active mutant thereof. To fuse with a target nerve cell, such as a cell from the central nervous system cell (e.g., neurons, glial cells including oligodendrocytes, astrocytes and microglia), the envelope protein can be a rabies glycoprotein or a biologically active mutant thereof, a Mokola virus glycoprotein or a biologically active mutant thereof, a Semliki Forest virus glycoprotein or a biologically active mutant thereof, a Venezuelan equine encephalitis virus glycoprotein or a biologically active mutant thereof, or a VSV-G or a biologically active mutant thereof. To fuse with a target sensory cell, such as an auditory cell, including hair cells, cochlear cells, etc., the envelope protein can be an Ebola virus glycoprotein or a biologically active mutant thereof, a Marburg virus glycoprotein or a biologically active mutant thereof, or a VSV-G or a biologically active mutant thereof.WSGR Docket No.: 62697-751.601Chimeric Envelope Protein

[0169] The compositions of the present disclosure can include engineered envelope proteins. In some embodiments, the envelope protein is a chimeric envelope protein. In some embodiments, the engineered envelope protein is a chimeric envelope protein. In some embodiments, the chimeric envelope protein comprises a surface unit and a transmembrane unit. In some embodiments, the transmembrane unit comprises a cytoplasmic domain. In some embodiments, the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain. In some embodiments, the cytoplasmic domain is heterologous to BaEV envelope protein surface unit. In some embodiments, the surface unit comprises a BaEv envelope protein surface unit. In some embodiments, the transmembrane unit comprises a transmembrane domain and a R peptide. In some embodiments, the transmembrane unit comprises a cleavage sequence that is recognizable by a MMLV pro protein. In some embodiments, cleavage catalyzed by the MMLV pro protein releases the R peptide from the transmembrane unit. In some embodiments, the R cleavable sequence is cleavable by a MMLV protease. In some embodiment, the R cleavable sequence is cleavable by a HIV protease. In some embodiments, the R peptide is not an MLV envelope protein R peptide. In some embodiment, the cleavable sequence comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 236-243.

[0170] In some embodiments, the cytoplasmic domain is not an MLV envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain. In some embodiments, the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain.

[0171] In some embodiments, the transmembrane domain and the cytoplasmic domain are operably linked in a direction from N-terminus to C-terminus. In some embodiments, the cytoplasmic domain and the R peptide are operably linked in a direction from N-terminus to C-terminus.

[0172] In some embodiments, the surface unit is a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit or a biologically active mutant thereof, a Feline Leukemia Virus (FeLV) envelope protein surface unit or a biologically active mutant thereof, a Koala Retrovirus (KRV) envelope protein surface unit or a biologically active mutant thereof, a Reticuloendotheliosis Virus (ReEV) envelope protein surface unit or a biologically active mutant thereof, a Wooly Monkey Sarcoma Virus (WMSV) envelope protein surface unit or a biologically active mutant thereof, a Vesicular Stomatitis (VSV) envelope protein surface unit or a biologically active mutant thereof, a Human Endogenous Retrovirus (HERV) W480 envelope protein surface unit or a biologically active mutant thereof, a Gibbon Ape Leukemia Virus (GaLV) envelope protein surface unit or a biologically active mutant thereof.

[0173] In some embodiments, the transmembrane unit is a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit or a biologically active mutant thereof, a Feline Leukemia Virus (FeLV) envelope protein surface unit or a biologically active mutant thereof, a Koala Retrovirus (KRV) envelope protein surface unit or a biologically active mutant thereof, a Reticuloendotheliosis Virus (ReEV)WSGR Docket No.: 62697-751.601 envelope protein surface unit or a biologically active mutant thereof, a Wooly Monkey Sarcoma Virus (WMSV) envelope protein surface unit or a biologically active mutant thereof, a Vesicular Stomatitis (VSV) envelope protein surface unit or a biologically active mutant thereof, a Human Endogenous Retrovirus (HERV) W480 envelope protein surface unit or a biologically active mutant thereof, a Gibbon Ape Leukemia Virus (GaLV) envelope protein surface unit or a biologically active mutant thereof.

[0174] In some embodiments, the cytoplasmic domain is a Baboon Endogenous Retrovirus (BaEV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Feline Leukemia Vims (FeLV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Reticuloendotheliosis Vims (Re EV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Wooly Monkey Sarcoma Vims (WMSV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Vesicular Stomatitis (VSV) envelope protein cytoplasmic domain or a biologically active mutant thereof, a Human Endogenous Retrovims (HERV) W480 envelope protein cytoplasmic domain or a biologically active mutant thereof, a Gibbon Ape Leukemia Vims (GaLV) envelope protein cytoplasmic domain or a biologically active mutant thereof.

[0175] In some embodiments, the R peptide is a FeLV envelope protein R peptide or a biologically active mutant thereof, a KRV envelope protein R peptide or a biologically active mutant thereof, a ReEV envelope protein R peptide or a biologically active mutant thereof, a WMSV envelope protein R peptide or a biologically active mutant thereof, a VSV envelope protein R peptide or a biologically active mutant thereof, a HERV W480 envelope protein R peptide or a biologically active mutant thereof, a GaLV envelope protein R peptide or a biologically active mutant thereof.

[0176] In some embodiments, the chimeric envelope protein comprises a transmembrane domain. In some embodiments, the transmembrane domain is a BaEV envelope protein transmembrane domain or a biologically active mutant thereof, a FeLV envelope protein transmembrane domain or a biologically active mutant thereof, a KRV envelope protein transmembrane domain or a biologically active mutant thereof, a ReEV envelope protein transmembrane domain or a biologically active mutant thereof, a WMSV envelope protein transmembrane domain or a biologically active mutant thereof, a VSV envelope protein transmembrane domain or a biologically active mutant thereof, a HERV W480 envelope protein transmembrane domain or a biologically active mutant thereof, a GaLV envelope protein transmembrane domain or a biologically active mutant thereof.

[0177] In some embodiments, the transmembrane unit comprises a protease cleavage site. In some embodiments, the protease cleavage site is a BaEV protease cleavage site or a biologically active mutant thereof, a FeLV protease cleavage site or a biologically active mutant thereof, a HIV protease cleavage site or a biologically active mutant thereof, or a MLV envelope protein protease cleavage site or a biologically active mutant thereof. In some embodiment, the protease cleavage site comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 16.WSGR Docket No.: 62697-751.601

[0178] In some embodiments, the transmembrane domain, the cytoplasmic domain, and the R peptide are operably linked in a direction from N-terminus to C-terminus.

[0179] In some cases, the envelope protein comprises the sequences set forth in Table 1. In some cases, the envelope protein comprises the sequences set forth in Table 1 with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the envelope protein of the lipid delivery particle provided herein relative to the wild-type viral envelope protein. In some cases, the envelope protein comprises the sequences set forth in Table 1 and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0180] In some cases, the envelope protein comprises one or more of the sequences set forth in Table 1 with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the envelope protein of the lipid delivery particle provided herein relative to the wild-type viral envelope protein. In some cases, the envelope protein comprises one or more of the sequences set forth in Table 1 and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0181] In some cases, the envelope protein comprises any one of the sequences set forth in Table 1 with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the envelope protein of the lipid delivery particle provided herein relative to the wild-type viral envelope protein. In some cases, the envelope protein comprises any one of the sequences set forth in Table 1 and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0182] In some cases, the envelope protein comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 1. In some cases, the envelope protein comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104 In some cases, the envelope protein comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104 In some cases, the envelope protein comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope proteinWSGR Docket No.: 62697-751.601 comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104. In some cases, the envelope protein comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 83-104.

[0183] In some embodiments, the R peptide comprises any one of the sequences set forth in Table 2 with at least one substitution, deletion, or insertion. In some cases, the R peptide comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 2. In some cases, the R peptide comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In someWSGR Docket No.: 62697-751.601 cases, the R peptide comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274. In some cases, the R peptide comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 55, 57, 59, 250, 254, 258, 262, 266, 270, and 274.

[0184] In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 2. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60. In some cases, the R peptide is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 24, 56, 58, and 60.WSGR Docket No.: 62697-751.601

[0185] In some embodiments, the cytoplasmic domain comprises any one of the sequences set forth in Table 3 with at least one substitution, deletion, or insertion. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 3. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273. In some cases, the cytoplasmic domain comprises anWSGR Docket No.: 62697-751.601 amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 65, 67, 69, 71, 73, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

[0186] In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 3. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76. In some cases, the cytoplasmic domain is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 66, 68, 70, 72, 74, and 76.

[0187] In some embodiments, the transmembrane domain comprises any one of the sequences set forth in Table 8 with at least one substitution, deletion, or insertion. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%,WSGR Docket No.: 62697-751.60194%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 8. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115. In some cases, the transmembrane domain comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 77, 79, 81, 105, 107, 111, 113, and 115.

[0188] In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 8. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78,WSGR Docket No.: 62697-751.60180, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106,108. 112. 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80,82. 106. 108. 112. 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116. In some cases, the transmembrane domain is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

[0189] In some embodiments, the surface unit comprises any one of the sequences set forth in Table 9 with at least one substitution, deletion, or insertion. In some cases, the surface unit comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 9. In some cases, the surface unit comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 50% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 60%WSGR Docket No.: 62697-751.601 sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 70% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 75% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 80% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 85% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 90% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 95% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 96% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 97% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 98% sequence identity to SEQ ID NO: 117. In some cases, the surface unit comprises an amino acid sequence that has at least about 99% sequence identity to SEQ ID NO: 117.

[0190] In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 9. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 50% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 60% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 70% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 75% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to SEQ ID NO: 118 In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 80% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 85% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 90% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 95% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 96% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 97% sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 98%WSGR Docket No.: 62697-751.601 sequence identity to SEQ ID NO: 118. In some cases, the surface unit is encoded by a nucleic acid sequence that has at least about 99% sequence identity to SEQ ID NO: 118.

[0191] In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.WSGR Docket No.: 62697-751.601

[0192] In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 152, 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

[0193] In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequenceWSGR Docket No.: 62697-751.601 identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180. In some cases, the transmembrane unit comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166-173 and 175-180.

[0194] In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, theWSGR Docket No.: 62697-751.601 transmembrane unit is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196. In some cases, the transmembrane unit is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181-189 and 191-196.

[0195] In some embodiments, the chimeric envelope protein comprises any one of the sequences set forth in Table 10 or Table 14 with at least one substitution, deletion, or insertion. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 10 or Table 14. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125,127. 129. 131. 133. 135. 139. 141. 143. 145. 147. 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143,145. 147. 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139,141. 143. 145. 147. 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 80%, 81%, 82%,WSGR Docket No.: 62697-751.60183%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131,133. 135. 139. 141. 143. 145. 147. 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220- 227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129,131. 133. 135. 139. 141. 143. 145. 147. 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220- 227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220- 227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220-227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220- 227. In some cases, the chimeric envelope protein comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 125, 127, 129, 131, 133, 135, 139, 141, 143, 145, 147, 149, and 220-227.

[0196] In some embodiments, the chimeric envelope protein comprises any one of the sequences set forth in Table 11 with at least one substitution, deletion, or insertion. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 11. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132,134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148, 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128,130. 132. 134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148,WSGR Docket No.: 62697-751.601150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122,124. 126. 128. 130. 132. 134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134,136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148, 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132,134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148, 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128,130. 132. 134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148, 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122,124. 126. 128. 130. 132. 134. 136. 140. 142. 144. 146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144,146. 148. 150 and 228-235. In some cases, the chimeric envelope protein is encoded by a nucleic acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 126, 128, 130, 132, 134, 136, 140, 142, 144, 146, 148, 150 and 228-235.

[0197] For instance, N-terminal methionine can be absent from the envelope protein of the lipid delivery particle provided herein relative to the wild-type viral envelope protein.Table 1. Exemplary envelope proteins from virus originWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601Table 2. Exemplary envelope protein R peptides from virus originTable 3. Exemplary envelope protein cytoplasmic domains from virus originWSGR Docket No.: 62697-751.601Table 8. Exemplary envelope protein transmembrane domains from virus originWSGR Docket No.: 62697-751.601Table 9. Exemplary surface unit from virus originWSGR Docket No.: 62697-751.601Table 10. Exemplary full length envelope protein amino acid constructsWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601Table 11. Exemplary full length envelope protein nucleic acid constructsWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601

[0198] The present disclosure contemplates the use of the herein disclosed engineered chimeric envelope proteins in viral-like particles and lipid delivery particles known in the art.

[0199] In some cases, a site (e.g., a cut site) in the cytoplasmic tail may be substituted. The substitution of the cut site may affect a cutting efficiency of a protease (e.g., a MLV protease and / or a HIV protease). For example, a native QALILT cut site may be replaced in a FeLV cytoplasmic tail. In some cases, the cytoplasmic tail of the envelope protein or unit of the envelope protein described herein may comprise 1 cut site, 2 cut sites, 3 cut sites, 4 cut sites, 5 cut sites, or greater than about 5 cut sites. FIGs. 31A-31C show the residue positions in the amino acid sequence of the cut sites described herein.

[0200] In some cases, an amino acid sequence of an envelope protein unit (e.g., surface unit) described herein may comprise an amino acid sequence as set forth in Table 14. In some cases, an amino acid sequence of an envelope protein unit (e.g., surface unit) described herein may comprise an amino acid sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in Table 14. In some cases, an amino acid sequence of an envelope protein unit (e.g., surface unit) described herein may comprise an amino acid sequence with at most about 99%, at most about 98%, at most about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in Table 14. In some cases, an amino acid sequence of an envelope protein unit (e.g., surface unit) described herein may comprise an amino acid sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 220-227. In some cases, an amino acidWSGR Docket No.: 62697-751.601 sequence of an envelope protein unit (e.g., surface unit) described herein may comprise an amino acid sequence with at most about 99%, at most about 98%, at most about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 220-227.

[0201] In some cases, a nucleotide sequence of an envelope protein unit (e.g., surface unit) described herein may comprise a nucleotide sequence as set forth in Table 15. In some cases, a nucleotide sequence of an envelope protein unit (e.g., surface unit) described herein may comprise a nucleotide sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in Table 15. In some cases, a nucleotide sequence of an envelope protein unit (e.g., surface unit) described herein may comprise a nucleotide sequence with at most about 99%, at most about 98%, at most about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in Table 15. In some cases, a nucleotide sequence of an envelope protein unit (e.g., surface unit) described herein may comprise a nucleotide sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 228-235. In some cases, a nucleotide sequence of an envelope protein unit (e.g., surface unit) described herein may comprise a nucleotide sequence with at most about 99%, at most about 98%, at most about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 228-235.

[0202] In some cases, the cytoplasmic tail of the envelope protein (e.g., envelope protein surface unit) may comprise a cut site with an amino acid sequence as set forth in Table 14. In some cases, the cytoplasmic tail of the envelope protein (e.g., envelope protein surface unit) may comprise a cut site with an amino acid sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in Table 15. In some cases, the cytoplasmic tail of the envelope protein (e.g., envelope protein surface unit) may comprise a cut site with an amino acid sequence with at most about 99%, at most about 98%, at mostWSGR Docket No.: 62697-751.601 about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in Table 15. In some cases, the cytoplasmic tail of the envelope protein (e.g., envelope protein surface unit) may comprise a cut site with an amino acid sequence with at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or greater than about 99% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 236-242. In some cases, the cytoplasmic tail of the envelope protein (e.g., envelope protein surface unit) may comprise a cut site with an amino acid sequence with at most about 99%, at most about 98%, at most about 97%, at most about 96%, at most about 95%, at most about 94%, at most about 93%, at most about 92%, at most about 91%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, at most about 65%, at most about 60%, or less than about 60% sequence identity to a sequence as set forth in any one of SEQ ID NOs.: 236-242.

[0203] Without wishing to be bound by theory, the cut sites or cleavage sites comprising an amino acid sequence as set forth in any one of SEQ ID NOs.: 236-242 may enhance a cutting efficiency of a protease (e.g., a MLV protease and / or a HIV protease) compared to a cutting efficiency of the protease at a cut site that does not comprise an amino acid sequence as set forth in any one of SEQ ID NOs.: 236-242. In some embodiment, the cut site or cleavage site is heterologous to the transmembrane domain. In some embodiment, the cut site or cleavage site is heterologous to the cytoplasmic tail.Table 14. Exemplary full length envelope protein amino acid constructsWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601Table 15. Exemplary full length envelope protein nucleic acid constructsWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601Table 16. Exemplary sequence of protease cleavage siteWSGR Docket No.: 62697-751.601PLASMA MEMBRANE RECRUITMENT ELEMENT

[0204] In some aspects, the lipid delivery particle provided herein comprises a plasma membrane recruitment element. The lipid delivery particle disclosed herein can comprise a membrane. In some cases, the membrane encapsulates a payload. In some cases, the lipid delivery particle comprises a plasma membrane recruitment element, for example, inside the cavity of the lipid delivery particle. The plasma membrane recruitment element can localize itself to the membrane of the lipid delivery particles. The plasma membrane recruitment element can be utilized to recruit a component (e.g., a payload) to the membrane of the lipid delivery particles via forming a chimeric protein of the plasma membrane recruitment element and a component to be localized to the membrane or other mechanisms of attachment. In some cases, the membrane encapsulates a protein core. In some cases, at least a portion of the plasma membrane recruitment element forms the basic structure of the lipid delivery particle, such as a portion of the protein core inside the lipid delivery particle. In some cases, at least a portion of the plasma membrane recruitment element binds to the membrane of the lipid delivery particle from the inside.

[0205] The plasma membrane recruitment element can play a role in the assembly of the lipid delivery particle, such as packing various components (e.g., a payload) into the lipid delivery particles. The plasma membrane recruitment element can direct budding of the lipid delivery particles from a producer cell. In some cases, expressing plasma membrane recruitment element alone or together with an envelope protein disclosed herein in a producer cell can lead to formation of the lipid delivery particle.

[0206] In some cases, the plasma membrane recruitment element has a viral origin. For instance, the plasma membrane recruitment element comprises a retroviral gag protein, e.g., a retroviral polyprotein that comprises one or more of a matrix (MA) polypeptide, an RNA-binding phosphoprotein polypeptide, a capsid (CA) polypeptide, or a nucleocapsid (NC) polypeptide. The plasma membrane recruitment element can comprise HIV gag or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a gag from murine leukemia virus (MLV) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a gag from Moloney murine leukemia virus (MMLV) or a biologically active mutant thereof. In some cases, the plasma membrane recruitment element forms structural protein that forms the protein core of the lipid delivery particles described herein. The plasma membrane recruitment element can comprise Respiratory syncytial virus (RSV) M or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Human Papillomavirus (HPV) L 1 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise HPV L2 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Hepatitis B virus (HBV) core protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Hepatitis C virus (HCV) core protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise hepatitis E virus (HeV) M protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Chikungunya virus (CHIKV) C-E3-E2-6k-El or a biologically active mutant thereof. The plasma membrane recruitment element can comprise RSV NP or a biologically active mutant thereof. The plasma membrane recruitment element can comprise HumanWSGR Docket No.: 62697-751.601 metapneumovirus (HMPV) M or a biologically active mutant thereof. The plasma membrane can comprise a glycoprotein from a flavivirus. The flavivirus can comprise Chikungunya virus, Zika virus, Dengue virus, or West Niles virus. The plasma membrane recruitment element can comprise Zika virus (ZIKV) C or a biologically active mutant thereof. The plasma membrane recruitment element can comprise ZIKV prM / M or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Dengaue virus (DENV) C-prM or a biologically active mutant thereof. The plasma membrane recruitment element can comprise West Nile Virus (WNV) prME protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise WNV CprME protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Filovirus VP40 or Z protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Baculovirus Pl protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Rotavirus VP7 or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Rotavirus VP2 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Rotavirus VP6 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Porcine Circovirus Type 2 (PCV2) capsid or a biologically active mutant thereof. The plasma membrane recruitment element can comprise baculovirus VP2 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise baculovirus VP5 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise baculovirus VP3 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise or baculovirus VP7 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Ebola nucleocapsid or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Parovirus VP 1 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Parovirus VP2 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Newcastle disease virus (NDV) M protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Human polyomavirus 2 (JCPyV) VP1 protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise Human parainfluenza virus type 3 (HPIV3) M protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise HPIV3N protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise or Mumps virus (MuV) M proteins or a biologically active mutant thereof. The plasma membrane recruitment element can comprise SARS M protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise SARS E protein or a biologically active mutant thereof. The plasma membrane recruitment element can comprise SARS N protein or a biologically active mutant thereof.

[0207] In some cases, the plasma membrane recruitment element is a mammalian protein or part thereof. For example, the plasma membrane recruitment element can include a pleckstrin homology (PH) domain or a transmembrane domain of a mammalian protein, such as a mouse protein or a human protein. In some cases, the plasma membrane recruitment element has a human origin. Utilizing the plasmaWSGR Docket No.: 62697-751.601 membrane recruitment element of a human origin in the lipid delivery particle can give rise to reduced immunogenicity for administration to a human subject. The plasma membrane recruitment element can include a gag from human endogenous retrovirus, such as Human Endogenous Retrovirus K (e.g., HERV- K113, HERV-K101, HERV-K102, HERV-K104, HERV-K107, HERV-K108, HERV-K109, HERV- K115, HERV- KI lp22, and HERV-K12ql3) and Human Endogenous Retrovirus-W (HERV-W) or a biologically active mutant thereof. The plasma membrane recruitment element can include a hGAGKcon or a biologically active mutant thereof. The plasma membrane recruitment element can include an endogenous gag of a mammal (e.g., human) from retrotransposons (e.g., Arc from vertebrate lineage of Ty3 / gypsy retrotransposon), which are also ancestral to retroviruses. In some cases, the plasma membrane recruitment element comprises a portion from human Arc.

[0208] The plasma membrane recruitment element can include a pleckstrin homology (PH) domain from a mammalian protein or a biologically active mutant thereof. The plasma membrane recruitment element can include a pleckstrin homology (PH) domain from a human protein or a biologically active mutant thereof. The PH domains can play a role in protein-membrane interactions via binding to phosphatidylinositol phosphate (PIP), for example PIP2 or PIP3, or other lipids or proteins within the membrane of the lipid delivery particles. PH domains with different sequences can have varied affinities and selectivity when binding different PIPs. The plasma membrane recruitment element can include a PH domain of phospholipase C51 (e.g., human phospholipase C51) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of Aktl (e.g., human Aktl) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a mutant PH domain of human Aktl with E17K substitution or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of 3 -phosphoinositide-dependent protein kinase 1 (e.g. , human 3 -phosphoinositide-dependent protein kinase 1) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of Dappl (e.g, human Dappl) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of Grpl (e.g., mouse Grpl) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of human Grpl or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of OSBP (e.g., human OSBP) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of Btkl (e.g. , human Btkl) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of FAPP1 (e.g., human FAPP1) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of CERT (e.g., human CERT) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of PKD (e.g. , human PKD) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of PHLPP1 (e.g., human PHLPP1) or a biologically active mutant thereof. The plasma membrane recruitment element can comprise a PH domain of SWAP70 (e.g., human SWAP70) or a biologically active mutant thereof. The plasma membrane recruitmentWSGR Docket No.: 62697-751.601 element can comprise a PH domain of MAPKAP1 (e.g., human MAPKAP1) or a biologically active mutant thereof.

[0209] The plasma membrane recruitment element can also include a membrane protein (e.g., a human membrane protein), a transmembrane domain thereof, or a biologically active mutant thereof. For example, the transmembrane domain of a human protein can be a tetraspanin or a biologically active mutant thereof. In some cases, the plasma membrane recruitment element comprises a transmembrane domain of human CD9 or a biologically active mutant thereof. In some cases, the plasma membrane recruitment element comprises a transmembrane domain of human CD47 or a biologically active mutant thereof. In some cases, the plasma membrane recruitment element comprises a transmembrane domain of human CD63 or a biologically active mutant thereof. In some cases, the plasma membrane recruitment element comprises a transmembrane domain of human CD81, or a biologically active mutant thereof.

[0210] The plasma membrane recruitment element can comprise a retroviral gag or a biologically active mutant thereof. The mutant of a retroviral gag can include only a portion of the retroviral gag. The plasma membrane recruitment element can include a gag of an alpha retrovirus or a biologically active mutant thereof. The plasma membrane recruitment element can a beta retrovirus or biologically active mutant thereof. The plasma membrane recruitment element can include a gamma retrovirus or biologically active mutant thereof. The plasma membrane recruitment element can include a delta retrovirus or biologically active mutant thereof. The plasma membrane recruitment element can include or biologically active mutant thereof. The plasma membrane recruitment element can include an epsilon retrovirus or biologically active mutant thereof. The plasma membrane recruitment element can include a spumavirus or biologically active mutant thereof. The retroviral gag can include a gag of HIV (e.g., HIV-1), a gag of murine leukemia virus (MLV), a gag of Moloney murine leukemia virus (MMLV), a gag of Simian immunodeficiency virus (SIV), a gag of Rous sarcoma virus (RSV), a gag of human T-cell leukemia virus type-1 (HTLV), or a gag of bovine leukemia virus (BLV), or a biologically active mutant thereof. The plasma membrane recruitment element can include a gag of HIV (e.g., HIV-1) or a biologically active mutant thereof. The plasma membrane recruitment element can include a gag of MLV or a biologically active mutant thereof. The plasma membrane recruitment element can include a gag of RSV or a biologically active mutant thereof. The plasma membrane recruitment element can include a gag of Friend murine leukemia virus (FMLV) or biologically active mutant thereof.

[0211] In some cases, the plasma membrane recruitment element comprises an amino acid sequence having at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 4A.

[0212] In some cases, the plasma membrane recruitment element comprises one or more of the sequences set forth in Table 4A with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the plasma membrane recruitment element of the lipid delivery particle provided herein relative to the wild-type plasma membrane recruitment element. In some cases, the plasma membrane recruitment element comprises one orWSGR Docket No.: 62697-751.601 more of the sequences set forth in Table 4A and a heterologous peptide sequence fused to the N- terminal or C-terminal.

[0213] In some cases, the plasma membrane recruitment element comprises any one of the sequences set forth in Table 4A with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the plasma membrane recruitment element of the lipid delivery particle provided herein relative to the wild-type plasma membrane recruitment element. In some cases, the plasma membrane recruitment element comprises any one of the sequences set forth in Table 4A and a heterologous peptide sequence fused to the N- terminal or C-terminal.

[0214] In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4A with a further truncation on the N-terminus. For example, for those amino acid sequences start with a N-terminal methionine, the N-terminal methionine can be absent. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4A with a further truncation on the C-terminus. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4A with one amino acid substitution. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4A with two or more amino acid substitutions. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4A and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0215] In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 4A. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305 In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%,WSGR Docket No.: 62697-751.60186%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 90% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305 In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 285-305.Table 4A. Exemplary wild type gag polyprotein and the corresponding amino acid sequencesWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601

[0216] In some cases, the plasma membrane recruitment element comprises one or more of the sequences set forth in Table 4B with at least one amino acid substitution, deletion, or insertion. For instance, N-terminal methionine can be absent from the plasma membrane recruitment element of the lipid delivery particle provided herein relative to the wild-type viral plasma membrane recruitment element. In some cases, the plasma membrane recruitment element comprises one or more of theWSGR Docket No.: 62697-751.601 sequences set forth in Table 4B and a heterologous peptide sequence fused to the N-terminal or C- terminal.

[0217] In some cases, the plasma membrane recruitment element comprises any one of the sequences set forth in Table 4B with at least one amino acid substitution, deletion, or insertion. For instance, N- terminal methionine can be absent from the plasma membrane recruitment element of the lipid delivery particle provided herein relative to the wild-type viral plasma membrane recruitment element. In some cases, the plasma membrane recruitment element comprises any one of the sequences set forth in Table 4B and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0218] In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4B with a further truncation on the N-terminus. For example, forthose amino acid sequences start with a N-terminal methionine, the N-terminal methionine can be absent. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4B with a further truncation on the C-terminus. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4B with one amino acid substitution. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4B with two or more amino acid substitutions. In some cases, the plasma membrane recruitment element comprises the sequences set forth in Table 4B and a heterologous peptide sequence fused to the N-terminal or C-terminal.

[0219] In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 4B. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 50% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 60% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 70% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 75% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 80% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 85% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 90% sequenceWSGR Docket No.: 62697-751.601 identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 95% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 96% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 97% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48. In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 98% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 In some cases, the plasma membrane recruitment element comprises an amino acid sequence that has at least about 99% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48.Table 4B. Exemplary plasma membrane recruitment elements and their sequencesWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601*hGAGKCOn is a consensus sequence derived from ten proviral GAG sequences encoded by human genomic sequences. The GAG sequences used to derive this consensus GAG sequence are from the following HERVs: HERV-K113, HERV-K101, HERV-K102, HERV-K104, HERV-K107, HERVK108, HERV-K109, HERV-K115, HERV- KI lp22, and HERV-K12ql3.

[0220] In some cases, the lipid delivery particle disclosed herein comprises a protein core that is composed of at least a structural protein of a viral origin, for instance, a retroviral gag protein. In some of these cases, the lipid delivery particle comprises a retroviral gag-pro-pol polyprotein, e.g., a gag-pro-pol poly protein from HIV, MMLV, or FMLV, which can help assemble a protein core of the lipid delivery particle. In some of these cases, some of the gag-pro-pol polyprotein is cleaved, e.g., by pro (protease) present freely or in the gag-pro-pol polyprotein. Without wishing to be bound by any particular theory, the cleavage by pro can be inefficient, and the resultant cleavage products can include gag polyprotein, gag -pro polyprotein, free pro, and free pol (polymerase). In some cases, a retroviral gag polyp rotein can be further cleaved into MA, CA, NC, and other small fragments, if any. In some other cases, the lipid delivery particle comprises a retroviral gag -pro polyprotein without the pol component, and the gag-pro polyprotein can help form a protein core of the lipid delivery particle. The gag -pro can also be cleaved by pro, in some cases, inefficiently, into separate gag and pro proteins. In some cases, there can be different plasma membrane recruitment elements in a lipid delivery particle. For instance, a gag-pro or gag-pro-pol polyprotein from one species of virus (e.g., a retrovirus, e.g., a HIV) can help assemble form a protein core of the lipid delivery particle, while a chimeric protein in the lipid delivery particle, discussed infra, can comprise a payload fused with a gag protein from a different species of virus (e.g., an MMLV), or from a HERV, or a PH domain or transmembrane domain of a huma protein (e.g., a PH domain of human Aktl with E17K substitution).CHIMERIC PROTEIN

[0221] In aspects, the present disclosure provides a chimeric protein comprising a plasma membrane recruitment element and a payload that is a protein or a fragment thereof. In some aspects, the lipid delivery particle comprises a chimeric protein comprising a plasma membrane recruitment element and a payload that is a protein or a fragment thereof. In some cases, the plasma membrane recruitment element and the payload are fused directly in the chimeric protein. In other cases, the plasma membrane recruitment element and the payload are fused indirectly via a linker. In some cases, the linker between the plasma membrane recruitment element and the payload is a cleavable linker that is recognized by a protease.

[0222] The chimeric protein (e.g., comprising a gag protein) can form at least part of a protein core of the lipid delivery particle. A lipid delivery particle can comprise two or more chimeric proteins. The chimeric protein can include a structural protein. The structural protein can comprise a plasma membrane recruitment element (e.g., retroviral gag protein). The plasma membrane recruitment element can be fused to a payload. In some cases, the two or more chimeric proteins comprise the same structural protein. In some cases, the two or more chimeric proteins comprise different structural proteins. In some cases, theWSGR Docket No.: 62697-751.601 two or more chimeric proteins comprise different payloads. In some cases, the chimeric protein comprises a payload that comprises a nucleic acid-binding moiety. In some cases, the payload further comprises a guide nucleic acid molecule that forms a ribonucleoprotein complex with the nucleic acid-binding moiety. In some cases, the chimeric protein is suitable for delivery by a lipid delivery particle disclosed herein.

[0223] In some cases, the lipid delivery particle of the present disclosure further comprises a protease that recognizes the cleavable linker in the chimeric protein and cuts the chimeric protein at the cleavable linker. As a result of the cleavage at the cleavable linker by the protease, the payload can be separated from the plasma membrane recruitment element. In some cases, the payload is present as a "free" entity separate from the plasma membrane recruitment element. For instance, the payload can be free and present within an inside of the protein core of the lipid delivery particle. In some cases, the protease is part of a second chimeric protein comprising a second plasma membrane recruitment element and the protease, where the second plasma membrane recruitment element can be either different from or same as the plasma membrane recruitment element that is fused with the payload.

[0224] In some cases, the chimeric protein disclosed herein also comprises one or more non-cleavable linkers that operably link components together. The non-cleavable linker can be any suitable linker sequence that is used for chimeric protein construction, such as peptide linkers that consist of glycine (Gly) and serine (Ser) residues. In some embodiments, the non-cleavable linker comprises an amino acid sequence selected from the group consisting of: (GS)x (SEQ ID NO: 564), (GGS)x (SEQ ID NO: 565), (GGGGS)x (SEQ ID NO: 566), (GGSG)x (SEQ ID NO: 567), and (SGGG)x (SEQ ID NO: 568), and wherein x is an integer from 1 to 50.

[0225] In some cases, the chimeric protein of the present disclosure comprises a nuclear export signal (NES) sequence that can direct transport of the chimeric protein out of the nucleus of a cell, e.g. , a producer cell.

[0226] In some cases, the chimeric protein disclosed herein has one of the following configurations of components positioned in an order from N-terminus to C-terminus:[plasma membrane recruitment element] -[cleavable linker] -[payload];[plasma membrane recruitment element]-[n * NES]-[cleavable linker] -[payload]; [plasma membrane recruitment element] -[cleavable linker] -[payload]-[n * NES]; [plasma membrane recruitment element] -[cleavable linker]-[n * NES]-[payload];[plasma membrane recruitment element] -[cleavable linker l]-[payload] -[cleavable linker 2]-[n * NES]; [payload] -[cleavable linker]-[n * NES]-[plasma membrane recruitment element];[payload]-[n * NES]-[cleavable linker] -[plasma membrane recruitment element]; [n * NES]-[payload]- [cleavable linker] -[plasma membrane recruitment element];[n * NES] -[cleavable linker l]-[payload]-[cleavable linker 2] -[plasma membrane recruitment element]; and[payload] -[cleavable linker] -[plasma membrane recruitment element]; wherein n is an integer in the range of from 1 to 10, and denotes the number of repeats of the NES sequence. Non-cleavable linker sequence can be present or absent in any of the foregoing configurationsWSGR Docket No.: 62697-751.601 between any two neighboring components. As provided herein, the payload sequence in the chimeric protein can have one or more NLS sequences, at its N-terminus, C-terminus, or both.[n * NES] -[cleavable linker l]-[payload]-[cleavable linker 2] -[plasma membrane recruitment element]; and[payload] -[cleavable linker] -[plasma membrane recruitment element]; wherein n is an integer in the range of from 1 to 10, and denotes the number of repeats of the NES sequence. Non-cleavable linker sequence can be present or absent in any of the foregoing configurations between any two neighboring components. As provided herein, the payload sequence in the chimeric protein can have one or more NLS sequences, at its N-terminus, C-terminus, or both.Nuclear Export Signal

[0227] Direction of nuclear transport within the cell can be governed by nuclear targeting signals within payload proteins or coupled to (e.g., fused with) the payload proteins. As used herein, the term “nuclear export signal” refers to a sequence of amino acids that targets a payload protein for export from the nucleus. In some cases, a nuclear export signal (NES) is a short target peptide sequence containing four hydrophobic residues. These residues target the protein for export from the nucleus to the cytoplasm through the nuclear pore complex. A chimeric protein provided herein can comprise 1 NES, 2 NESs, 3 NESs, 4 NESs, 5 NESs, 6 NESs, 7 NESs, 8 NESs, 9 NESs, or 10 NESs. In some cases, the NES is located at the N-terminus, C-terminus, or in an internal region of the chimeric protein. In some cases, a NES is coupled between the plasma membrane recruitment element and the payload in the chimeric protein. In some cases, there is a cleavable linker between the plasma membrane recruitment element and the payload in the chimeric protein, and one or more NESs present on the same of the cleavable linker as the plasma membrane recruitment element.

[0228] In some cases, the NES sequence that is used in the chimeric protein comprises LQLPPLERLTL (SEQ ID NO: 403) derived from HIV-1 Rev protein, or any of the sequences having at least 80% identity thereto. In some cases, the NES sequence comprises LALKLAGLDI (SEQ ID NO: 416) derived from PKIa, or any of the sequences having at least 80% identity thereto. In some cases, the NES sequence that is used in the chimeric protein comprises an amino acid sequence as set forth in Table 5. In some cases, the NES sequence comprises any one of the sequences set forth in Table 5. In some cases, the NES sequence comprises one or more of the sequences set forth in Table 5. In some cases, the NES sequence comprises more than one, more than two, more than three, more than four, more than five, more than six, more than seven, more than eight, more than nine, or more than ten of the sequences set forth in Table 5. In some cases, the NES sequences comprises multiple sequences set forth in Table 5.

[0229] In some cases, the NES sequence comprises an amino acid sequence having 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any sequence listed in Table 5. In some cases, the NES sequence comprises an amino acid sequence having 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any sequence set forth in SEQ ID NOs: 353-453. In some cases, the NES sequence described herein comprises a sequence with greater thanWSGR Docket No.: 62697-751.60180% sequence identity to any sequence listed in Table 5. The transport of payload proteins within a cell is enabled through both NES and nuclear export receptors. In some cases, the NES described herein is associated with a nuclear export receptor (e.g., CRM-1). In some cases, the NES may be conditionally active or inactive. In some cases, the NES sequence disclosed herein comprises a sequence such as those described in T la Cour, et al., Nucleic Acids Res. 2003;31 ( 1 ) : 393 -396; and Xu D, et al. Mol Biol Cell. 2012 Sep;23(18):3673-6, each of which is incorporated herein by reference in its entirety. Any of the NES sequences described in the NES sequence database (NESdb®; prodata.swmed.edu / LRNes) or (NESbase; services.healthtech.dtu.dk / datasets / NESbase-1.0) can be used in a chimeric protein disclosed herein, e.g., for the purpose of packaging a payload into the molecular assembly, e.g., the lipid delivery particle.

[0230] In some cases, a chimeric protein disclosed herein include a nuclear export sequence (NES). In some cases, the NES facilitates localization of the chimeric protein in the cytosol of a target cell relative to the nucleus.

[0231] In some cases, a chimeric protein disclosed herein includes at least one NES sequences, such as, 2 or more, 3 or more, 4 or more, or 5 or more NES sequences. In some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) the N-terminus and / or the C- terminus of the chimeric protein. In some cases, the chimeric protein disclosed herein comprises only one NES sequence. In some cases, the chimeric protein disclosed herein comprises two NES sequences. In some cases, the chimeric protein disclosed herein comprises three NES sequences. In some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) the N- terminus of the chimeric protein. In some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) the C- terminus of the chimeric protein. In some cases, one or more NES sequences (3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) both the N-terminus and the C-terminus of the chimeric protein. In some cases, an NES sequence is positioned at the N- terminus and an NES sequence is positioned at the C-terminus of the chimeric protein.

[0232] In some cases, a payload is a protein that is delivered as part of the chimeric protein disclosed herein, e.g., operably linked to a structural protein (e.g., human endogenous retroviral structural protein or a Plasma membrane recruitment element). In some embodiments, the one or more NES sequences are positioned at or near the one or both ends of the payload protein sequence inside the chimeric protein. For example, in some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) the N-terminus and / or the C- terminus of the payload protein sequence. In some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) the N-terminus of the payload protein sequence. In some cases, one or more NES sequences (2 or more, 3 or more, 4 or more, or 5 or more NES sequences) are positioned at or near (e.g. , within 50 amino acids of) the C-terminus of the payload protein sequence. In some cases, one or more NES sequences (3 or more, 4WSGR Docket No.: 62697-751.601 or more, or 5 or more NES sequences) are positioned at or near (e.g., within 50 amino acids of) both the N-terminus and the C-terminus of the payload protein sequence. In some cases, an NES sequence is positioned at the N-terminus and an NES sequence is positioned at the C-terminus of the payload protein sequence. In some cases, the chimeric protein disclosed herein comprises only one NES sequence. In some cases, the chimeric protein comprises only one NES sequence, and the NES sequence is positioned at or near (e.g., within 50 amino acids of) the N-terminus of the payload protein.

[0233] In eukaryotic cells, transport of proteins between the nucleus and the cytoplasm can be mediated by transport factors in the karyopherin-[3 family, which are also known as importins and exportins. The direction of nuclear-cytoplasmic transport can be dictated by nuclear targeting signals within the payload proteins. Nuclear export sequences (NESs) can direct export of proteins from the nucleus to the cytoplasm. NESs can bind directly to the export karyopherin CRM1 (also known as exportin 1), which can escort payload proteins through the nuclear pore complex.Table 5. Exemplary NES sequencesWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601Nuclear Localization Signal

[0234] In some instances, a payload described herein comprises one or more nuclear localization sequences (NLS). As used herein, the term “nuclear localization signal” refers to a sequence of amino acids that targets a payload (e.g., a protein or a short polypeptide), which the NLS is present within or coupled to, to localize to the nucleus. In some cases, an NLS facilitates the import of a polypeptide comprising an NLS into the cell nucleus. A polypeptide can comprise 1 NLS, 2 NLSs, 3 NLSs, 4 NLSs, 5 NLSs, 6 NLSs, 7 NLSs, 8 NLSs, 9 NLSs, or 10 NLSs. In some cases, the NLS is located at the N- terminus, C-terminus, or in an internal region of the polypeptide. In some cases, a NLS is coupled to a nucleic acid binding domain described elsewhere herein. In some cases, a NLS is coupled to a nucleic acid modifying domain described elsewhere herein. In some cases, a NLS is coupled to a guidable polypeptide domain, a deaminase domain, or a reverse transcriptase domain. In some cases, a NLS is covalently linked to a nucleic acid binding domain described elsewhere herein. In some cases, a NLS is covalently linked to a nucleic acid modifying domain described elsewhere herein. In some cases, a NLS is covalently linked to a guidable polypeptide domain, a deaminase domain, or a reverse transcriptase domain. In some cases, a nucleic acid binding domain does not comprise an NLS. In some cases, a nucleic acid binding domain does not comprise an NLS. In some cases, a guidable polypeptide domain, a deaminase domain, or a reverse transcriptase domain does not comprise an NLS. Examples of NLS are provided in Table 6 below.

[0235] In some cases, the NLS comprises an amino acid sequence as set forth in Table 6. In some cases, the NLS comprises any one of the sequences set forth in Table 6. In some cases, the NLS comprises one or more of the sequences set forth in Table 6. In some cases, the NLS comprises more than one of the sequences set forth in Table 6. In some cases, the NLS comprises multiple sequences set forth in Table 6.WSGR Docket No.: 62697-751.601In some cases, NLS sequence can comprise an amino acid sequence having 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any sequence listed in Table 6. In some cases, the NLS sequence described herein can comprise a sequence with greater than 80% sequence identity to any sequence listed in Table 6. In some cases, NLS sequence can comprise an amino acid sequence having 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any sequence set forth in SEQ ID NOs: 454-477.

[0236] In some cases, a chimeric protein disclosed herein includes a nuclear localization sequence (NLS). In some cases, the NLS facilitates delivery of the chimeric protein, or a payload released from the chimeric protein (for instance, released from the chimeric protein following cleavage of a cleavable linker), into the nucleus of a target cell.

[0237] In some cases, a payload is a protein and is delivered as part of the chimeric protein disclosed herein, e.g., operably linked to a structural protein (e.g, plasma membrane recruitment element). In some embodiments, the one or more NLS sequences are positioned at or near the one or both ends of the payload protein sequence of the chimeric protein. In some cases, a chimeric protein includes (e.g., is fused to) between 2 and 5 NLS sequences (e.g., 2-4, or 2-3 NLSs). Examples of NLS sequences include an NLS sequence derived from: the NLS of the SV40 virus large T-antigen, having the amino acid sequence PKKKRKV (SEQ ID NO: 468); the NLS from nucleoplasmin (e.g., the nucleoplasmin bipartite NLS with the sequence KRPAATKKAGQAKKKK (SEQ ID NO: 460); the c-myc NLS having the amino acid sequence PAAKRVKLD (SEQ ID NO: 467) or RQRRNELKRSP (SEQ ID NO: 541); the hRNPAl M9 NLS having the sequence NQSSNFGPMKGGNFGGRSSGPYGGGGQYFAKPRNQGGY (SEQ ID NO: 542); the sequence RMRIZFKNKGKDTAELRRRRVEVSVELRKAKKDEQILKRRNV (SEQ ID NO: 543) of the IBB domain from importin-alpha; the sequences VSRKRPRP (SEQ ID NO: 477) and PPKKARED (SEQ ID NO: 544) of the myoma T protein; the sequence PQPKKKPL (SEQ ID NO: 545) of human p53; the sequence SALIKKKKKMAP (SEQ ID NO: 546) of mouse c-abl IV; the sequences DRLRR (SEQ ID NO: 547) and PKQKKRK (SEQ ID NO: 548) of the influenza virus NS1; the sequence RKLKKKIKKL (SEQ ID NO: 549) of the Hepatitis virus delta antigen; the sequence REKKKFLKRR (SEQ ID NO: 550) of the mouse Mxl protein; the sequence KRKGDE VDGVDEV AKKKS KK (SEQ ID NO: 551) of the human poly(ADP-ribose) polymerase; and the sequence RKCLQAGMNLEARKTKK (SEQ ID NO: 552) of the steroid hormone receptors (human) glucocorticoid, and sequences having at least 80% identity to the foregoing. In some cases, an NLS comprises the amino acid sequence MDSLLMNRRKFLY QFKNVRWAKGRRETYLC (SEQ ID NO: 553).

[0238] Other examples of an NLS sequence include KRTADGSEFESPKKKRKV (SEQ ID NO: 462), KKTELQTTNAENKTKKL (SEQ ID NO: 554), KRGINDRNFWRGENGRKTR (SEQ ID NO: 555), RKSGKIAAIVVKRPRK (SEQ ID NO: 556), and MDSLLMNRRKFLY QFKNVRWAKGRRETYLC (SEQ ID NO: 463), SPKKKRKVEAS (SEQ ID NO: 557), encoded by AGCCCCAAGAAgAAGAGaAAGGTGGAGGCCAGC (SEQ ID NO: 558), GPKKKRKVAAA (SEQ ID NO: 559), as well as any of those described in Cokol et al., EMBO Rep., 2000, 1(5): 411-415 and Freitas et al., Current Genomics, 2009, 10(8): 550-7; Lu, J., et la., Cell Commun Signal 19, 60 (2021);WSGR Docket No.: 62697-751.601 international publication no. WO / 2001 / 038547, each of which is incorporated herein by reference in its entirety, and sequences having at least 80% identity to the foregoing.

[0239] In some embodiments, the chimeric protein comprises one NES sequence and two NLS sequences. In some cases of these embodiments, the NES sequence, NLS sequences, and the payload protein sequence are positioned in an order from N-terminus to C-terminus as follows: NES-NLS-payload protein-NLS. In some embodiments, the chimeric protein comprises two or more NES sequences and two NLS sequences. In some cases of these embodiments, the NES sequences, NLS sequences, and the payload protein sequence are positioned in an order from N-terminus to C-terminus as follows: n X NES(n >=2)-NLS-payload protein-NLS.Table 6. Exemplary NLS sequencesWSGR Docket No.: 62697-751.601Cleavable Linker

[0240] In some cases, the chimeric protein comprises a cleavable linker in between two or more components. For instance, the chimeric protein can comprise a cleavable linker between a payload protein sequence and a plasma membrane recruitment element sequence (e.g., retroviral gag protein sequence). In some cases, the cleavable linker separates the plasma membrane recruitment element sequence from a NLS sequence, and / or a NES sequence at its N-terminus or C-terminus. The cleavable linker can separate the payload protein sequence from the plasma membrane recruitment element sequence, NLS sequence, and / or NES sequence at its N-terminus or C-terminus. Examples of cleavable linker sequences that can be used in the chimeric protein include TSTLLMENSS (SEQ ID NO: 560), PRSSLYPALTP (SEQ ID NO: 561), VQALVLTQ (SEQ ID NO: 562), and PLQVLTLNIERR (SEQ ID NO: 563), and sequences having at least 80% identity to any one of the foregoing. Cleavable linkers suitable for use in the context of the present disclosure are known in the art and any suitable cleavable linker can be used in some embodiments of this disclosure, including, without limitation the cleavable linkers disclosed in U.S. Provisional Application No. 63 / 730,840, fded December 11, 2024 and U.S. Provisional Application No. 63 / 805,929, filed May 14, 2025, the entire contents of which are incorporated herein by reference.

[0241] The cleavable linker sequence provided herein can be a cleavable sequence that is recognized and cleaved by any applicable protease, such as a viral protease, a bacterial protease, or a eukaryotic protease (e.g., a protease derived from a plant, an animal, or a fungus). In some cases, the cleavable sequence is recognized by a retroviral protease (pro), such as pro protein derived from Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), HIV-1, HIV-2, EIAV, FIV, MAV, MMTV, MPMV, HFV, WDSV, HTLV-1, or BLV. In some cases, the viral protease disclosed herein comprises a viral protease described in Reynolds et al., “The SARS-CoV-2 SSHHPS Recognized by the Papain-like Protease.” ACS infectious diseases 2021: 7(6): 1483-1502; Farsani et al., “Identification of a Novel Human Rhinovirus C Type by Antibody Capture VIDISCA-454.” Viruses 2015: 7( l):239-251; and Kolykhalov et al., “Specificity of the hepatitis C virus NS3 serine protease: effects of substitutions at the 3 / 4A, 4A / 4B, 4B / 5A, and 5A / 5B cleavage sites on polyprotein processing.” Journal of Virology 1994: 68(11): 7525-33, each of which is incorporated herein by reference in its entirety. In some cases, the viral protease is the tobacco etch virus (TEV) protease, the hepatitis C (HCV) NS3 protease, adenovirus protease, alphavirus protease, flavivirus protease, herpesvirus protease, picomavirus protease, or the Moloney Murine Leukemia Virus (MMLV) protease. In some cases, the viral protease comprises an amino acid sequence at least 70%, 75%, 80%, 85%, 90%, 95% or 99% sequence identity to an amino acidWSGR Docket No.: 62697-751.601 sequence set forth in Table 13. In some cases, the viral protease comprises an amino acid sequence set forth in Table 13. In some cases, the viral protease comprises an amino acid sequence at least 70%, 75%, 80%, 85%, 90%, 95% or 99% sequence identity to any one of SEQ ID NOs: 197-219. In some cases, the viral protease comprises the amino acid sequence of any one of SEQ ID NOs: 197-219.Table 13: Exemplary amino acid sequence of the viral proteasesWSGR Docket No.: 62697-751.601WSGR Docket No.: 62697-751.601PAYLOAD

[0242] A payload in a lipid delivery particle of the present disclosure can comprise a protein, a polypeptide, a nucleic acid (e.g. , DNA or RNA), or any combinations thereof. In some embodiments, the lipid delivery particle comprises a payload protein. In some embodiments, the payload protein is a therapeutic protein. In some embodiments, the therapeutic protein comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof. In some embodiments, the therapeutic protein comprises a guidable polypeptide.

[0243] The payload can be a part of the chimeric protein disclosed herein or can comprise a part of the chimeric protein disclosed herein. Alternatively or additionally, the payload can include an entity in the lipid delivery particle separate from the chimeric protein disclosed herein. For instance, in some cases, the payload is a protein or polypeptide coupled to a plasma membrane recruitment element. In some cases, the payload comprises a first moiety (e.g., a nucleic acid-binding protein) that is fused to a plasma membrane recruitment element, and further comprises a second moiety that is coupled to the first moiety via covalent or non-co valent interaction. For instance, the first moiety can be a nucleic acid bindingWSGR Docket No.: 62697-751.601 protein that is fused with the plasma membrane recruitment element, and the second moiety can be a nucleic acid molecule that binds to the nucleic acid binding protein.

[0244] In some cases, a payload is directly packaged within the lipid delivery particles and delivered into a target cell in its free form. In some cases, a payload can be fused to a plasma membrane recruitment element (e.g., pleckstrin homology domain) and form a chimeric protein as part of the lipid delivery particles, and then delivered into the target cell. In some cases, the plasma membrane recruitment element (e.g. , pleckstrin homology domain) forms at least part of a protein core of the lipid delivery particle. In some embodiments, the payload in its free form or as part of a chimeric protein is within the inside cavity of the protein core of the lipid delivery particles disclosed herein. In some cases, the payload in its free form derives from a cleavage of the chimeric protein comprising the payload.

[0245] In some cases, a lipid delivery particle can deliver more than one payload. Each of the payloads can independently comprise nucleic acid-binding moiety, a nucleic acid-modifying moiety, a fusion protein, or a nucleic acid, or any combinations thereof.

[0246] In some embodiments, the plasma membrane recruitment element and the payload are coupled via any suitable method. Covalent coupling between the plasma membrane recruitment element and a payload peptide can include inteins that can form peptide bonds, direct protein-protein chimeras generated from a single reading frame. In some cases, nucleic acids base pairing to other nucleic acids via hydrogen bonding interactions (e.g., DNA / RNA, DNA / DNA, or RNA / RNA hybrids), protein-protein binding, or protein-nucleic acid molecule binding can be involved for the coupling between the plasma membrane recruitment element and the payload. Examples of protein-nucleic acid molecule binding include an RNA binding protein (RBP) and an RBP binding sequence (e.g., an RNA) that binds to the RBP. In some embodiments, each of the plasma membrane recruitment element and the payload is fused to a heterologous sequence, and the two heterologous sequences dimerize or multimerize with or without the need for a chemical compound to induce the protein-protein binding, such as a single-stranded nucleic acid sequence or protein dimerization domains). In some embodiments, each of the plasma membrane recruitment element and the payload is fused to one member of a pair of binding partners (e.g., antibody and its target antigen). In some embodiments, the plasma membrane recruitment element is fused to an RBP, and the payload is fused to a RBP binding sequence. Examples of suitable protein domains or nucleic acid molecules for forming the non-covalent connections include single chain variable fragments, nanobodies, affibodies, DmrA / DmrB / DmrC, FKBP / FRB, dDZFs, Leucine zippers, proteins that bind to DNA and / or RNA, optogenetic protein domains that can dimerize or multimerize in the presence of certain light wavelengths, proteins with quaternary structural interactions, and / or naturally reconstituting split proteins. Examples of RBPs and their RBP binding sequences that can be used include a sequence having at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in Table 7. Examples of RBPs and their RBP binding sequences that can be used include a sequence having at least about 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 478-WSGR Docket No.: 62697-751.601513. In some cases, the RBP comprises an amino acid sequence as set forth in Table 7. In some cases, the RBP comprises any one of the sequences set forth in Table 7. In some cases, the RBP comprises one or more of the sequences set forth in Table 7. In some cases, the RBP comprises more than one of the sequences set forth in Table 7. In some cases, the RBP comprises multiple sequences set forth in Table 7. In some cases, the RBP binding sequence comprises an amino acid sequence as set forth in Table 7. In some cases, the RBP binding sequence comprises any one of the sequences set forth in Table 7. In some cases, the RBP binding sequence comprises one or more of the sequences set forth in Table 7. In some cases, the RBP binding sequence comprises more than one of the sequences set forth in Table 7. In some cases, the RBP binding sequence comprises multiple sequences set forth in Table 7.Table 7. Exemplary RNA binding proteins (RBP) and corresponding RBP binding sequencesWSGR Docket No.: 62697-751.601Nucleic acid binding domains and nucleic acid modifying domains

[0247] In some cases, the payload comprises a nucleic acid-binding moiety, a nucleic acid-modifying moiety, a fusion protein, or a nucleic acid. In some cases, the payload comprises a nucleic acid-binding domain, e.g., a DNA-binding protein domain or polypeptide or an RNA-binding domain or polypeptide e.g., an RNA-binding protein (RBP). A nucleic acid-binding moiety can be capable of binding a nucleic acid. A nucleic acid-binding domain can bind to a nucleic acid in a nonspecific or a site-specific manner.

[0248] In some cases, the nucleic acid-binding moiety binds to a nucleic acid in a site-specific manner. For example, a nucleic acid-binding moiety can comprise an aptamer binding domain that selectively binds to a specific target. In some cases, a nucleic acid-binding moiety recognizes a specific recognition sequence in the target nucleic acid. In some cases, a nucleic acid-binding moiety comprises an aptamer binding domain. In some cases, a nucleic acid binding moiety selectively binds to a sequence or a structural element in a nucleic acid molecule. In some cases, an RNA-binding domain selectively binds to a specific sequence motif in an RNA molecule. In some cases, a nucleic acid-binding moiety selectivelyWSGR Docket No.: 62697-751.601 binds to a structural element in a nucleic acid molecule. For example, a nucleic acid-binding domain can bind to a stem -loop in a nucleic acid molecule.

[0249] In some cases, a nucleic acid-binding moiety is or comprises a guidable polypeptide domain, a transcriptional regulatory domain, or a nucleic acid-modifying domain. A guidable polypeptide domain can be capable of binding to a polynucleotide (e.g. an RNA guide) that can direct the guidable polypeptide domain a target site. In some cases, the guidable polypeptide domain forms a complex with the RNA guide and recognizes the target sequence through DNA-RNA base pairing. In some cases, a nucleic-acid binding moiety is or comprises a transcriptional regulatory domain. In other cases, a nucleic- binding moiety can help recruit a transcriptional repressor or activator to a target site. In some cases, a nucleic acid-binding moiety is or comprises a nucleic acid-modifying moiety. In some cases, the present disclosure uses nucleic acid-binding moieties to recruit a nucleic acid-modifying moiety to a target site. In some cases, a nucleic-acid binding moiety comprises catalytic activity. In other cases, a nucleic acidbinding moiety is catalytically inactive. In some cases, a nucleic-acid binding moiety comprising catalytic activity is modified to have a reduced level of activity compared to its wild-type counterpart.

[0250] In some cases, the payload in the present disclosure comprises a nucleic acid modifying domain. A nucleic acid-modifying domain can comprise a polypeptide domain, a nucleic acid or a combination thereof (e.g., a ribonucleoprotein complex). A nucleic acid-modifying domain can be capable of modifying nucleic acid, such as cleaving double -stranded nucleic acid; nicking a single-stranded nucleic acid; introducing a mutation, deletion, or insertion in a nucleic acid; methylating or demethylating a nucleic acid, or altering the structure of DNA (e.g., changing chromatin structure through modifying histones). For example, a nucleic acid modifying domain can comprise a nuclease domain, a nickase domain, a deaminase domain, a polymerase, reverse transcriptase domain, a recombinase domain, a transposase domain, or an epigenetic modifying domain. A nuclease domain can be capable of cleaving phosphodiester bonds between nucleotides in nucleic acids. A nuclease domain can comprise an exonuclease (e.g., a nuclease capable of cleaving nucleic acids from the ends) or an endonuclease (e.g., a nuclease capable of cleaving nucleic acids in the middle). In some cases, a nucleic acid modifying effector or nucleic acid binding domain is a nickase, which can be capable of cleaving a single-strand in a double-stranded DNA. Nucleic acid modifying domains can be useful for gene editing, or for regulating, activating, or inhibiting gene expression.

[0251] In some cases, the payload in the present disclosure comprises a guidable polypeptide domain (e.g., a CRISPR-Cas protein domain). In some cases, a guidable polypeptide domain is capable of binding to a polynucleotide (e.g. , a RNA guide) that directs it to a target site. In some cases, the guidable polypeptide domain forms a complex with the polynucleotide and recognizes the target sequence through DNA-RNA base pairing. In some cases, a guidable polypeptide domain is a CRISPR / CRISPR-associated (Cas) domain. A CRISPR domain can be a natural or an engineered domain. A Cas protein or domain can be derived from a CRISPR system or share structural and / or functional similarities to a protein involved in a CRISPR system. A CRISPR system is a system encoding DNA sequence arrays known as clustered regularly interspaced short palindromic repeats (CRISPRs), which can be found in microbial genomes orWSGR Docket No.: 62697-751.601 phage genomes. In some cases, CRISPR systems comprise genes encoding CRISPR-associated (Cas) proteins and / or small RNA guide molecules (e.g., crRNA or tracrRNA) that assemble with the CRISPR domain. In some cases, the CRISPR-Cas domain forms a complex with one or more RNA guide molecules to form an effector ribonucleoprotein complex. The effector ribonucleoprotein complex can recognize a target sequence through sequence specific DNA-RNA base pairing with a spacer sequence in the RNA guide. In some cases, target recognition activates one or more nuclease domains (e.g., a RuvC domain or HNH domain) in the CRISPR domain to make a double-stranded cut at the target DNA. A CRISPR-Cas domain complexed with an RNA guide can be capable of inactivating target gene through a gene knockout. In some cases, the CRISPR domain is used to enable gene insertion and / or deletion, which can inactivate, modify, or restore the gene’s function.

[0252] A CRISPR system can comprise single subunit or multi-subunit effectors. In some cases, a CRISPR system is a Class 1 CRISPR system. A Class 1 CRISPR system can be a type I, type III, or a type IV system. A Class 1 type I CRISPR system can comprise a multi-subunit effector. In some cases, a Class 1 type I CRISPR system comprises a protein or domain in the Cascade-Cas3 protein complex. A Class 1 type I CRISPR system can comprise a Cas6, Cas7, Cas5, Casl l, Cas8, or Cas3 domain. A Class 1 type III CRISPR system can comprise a multi-subunit effector. In some cases, a Class 1 type III CRISPR system comprises a Csm complex or a Cmr complex. In some cases, a Class 1 type III CRISPR system comprises a Cas6, a Cas7 (Csm3 or Cmr4), a Cas7-related (Csm5, Cmrl, or Cmr6), a Cas5 (e.g., Csm4 or Cmr5), a Casl 1 (e.g., Csm2 or Cmr3), or a CaslO (e.g., Csml or Cmr2) domain. A Class 1 type IV CRISPR system can comprise a Cas6, a Cas7, a Cas5, a Casl 1, a Cas8 (e.g., Csfl), or a DinG or CysH domain.

[0253] In some cases, a CRISPR system is a Class 2 CRISPR system. A Class 2 CRISPR system can be a Class 2 type II CRISPR system, a Class 2 type V CRISPR system, or a Class 2 type VI CRISPR system. A Class 2 type II CRISPR system can comprise a Cas9 domain. A Cas9 domain can be a SpyCas9, a GeoCas9, a SauCas9, a KhuCas9, a AinCas9, an FmaCas9, a SgaCas9, a ScCas9, a SauriCas9 domain. A Cas9 domain can be a hyperactive Cas9 domain. A Class 2 type V CRISPR system can comprise a Casl2 domain. A Casl2 domain can be a Casl2a, a Casl2b, a Casl2c, a Casl2d, a Casl2e, a Casl2f, a Casl2g, a Casl2h, a Casl2i, a Casl2j, a Cas 12k, a Cas 121, or a Cas 12m domain. A Class 2 type VI CRISPR system can comprise a Cas 13 domain.

[0254] In some cases, a CRISPR-Cas domain comprises one or more subdomains. For example, a Cas9 domain can comprise a Reel, a Rec2, a Rec3, a RuvC, an HNH, or a Wedge / PAM-interacting domain. A Casl2 domain can comprise a Reel, Rec2, a crRNA oligonucleotide binding domain (OBD), a Nuc domain, a PAM-interacting (PI) domain, or a RuvC domain. In some cases, the RuvC domain comprises nuclease activity. In some cases, the HNH domain comprises nuclease activity. The PAM-interacting domain can bind to a protospacer adjacent motif (PAM) sequence that is next to a target sequence in a target nucleic acid molecule. PAM recognition can help activate a nuclease domain to make a cut at the target sequence. In some cases, a CRISPR protein or domain is an engineered or mutated variant of a protein involved in a CRISPR system. An engineered or mutated CRISPR domain can comprise aWSGR Docket No.: 62697-751.601 truncation, a deletion of a part of one or more domains or subdomains, or a mutation of an active site (e.g., a RuvC active site or HNH active site). In some cases, a CRISPR domain with a mutation of one or more active sites is catalytically inactive (e.g., dCas9). In some cases, a CRISPR domain with one or more mutated active sites comprises less than 90%, less than 80%, less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, less than 5%, or less than 1% of the nuclease activity of its wildtype counterpart. For example, a dCas9 can result from the point mutations D10A in the RuvC domain and the point mutation H840A in the HNH domain. In other cases, a mutation can result in a CRISPR nickase. A nickase can generate nick or a single-stranded cut. A nickase can generate a nick in the strand complementary to the RNA guide (e.g., the targeting strand) or in the strand on the non-targeting strand. For example, a RuvC mutation D10A in a Cas9 domain can produce a Cas9 nickase domain that nicks the targeting strand. An HNH mutation H840A in a Cas9 domain can produce a Cas9 nickase domain that nicks the non-targeting strand.

[0255] In some cases, the payload in the present disclosure comprises a deaminase domain. The deaminase domain can be a natural or an engineered domain. A deaminase domain can be capable of carrying out deamination reactions in DNA. A deaminase domain can be capable of enabling the generation of base conversions or point mutations in a target nucleic acid. For example, a deaminase domain can be a cytidine deaminase domain or an adenosine deaminase domain. A cytidine deaminase domain can be capable of converting cytosine to uracil. A cytidine deaminase domain can be capable of enabling the conversion of a C-G base pair to a T-A base pair. For example, a cytidine deaminase can be or comprise a APOBEC1 cytidine deaminase. An adenosine deaminase domain can be capable of converting an adenosine to hypoxanthine. An adenosine deaminase domain can be capable of converting an adenosine to an inosine. An adenosine deaminase can comprise TadA or a TadA mutant. An adenosine deaminase domain can be capable of enabling the conversion of an A-T base pair to a G-C base pair. A deaminase domain can be a mutated variant. In some cases, a deaminase domain enables the conversion of C to G, A to I, or C to U.

[0256] In some cases, the payload in the present disclosure comprises a polymerase (e.g., reverse transcriptase). A polymerase can comprise a natural or an engineered domain. A polymerase can be capable of synthesizing nucleic acids. A polymerase can be a DNA polymerase or an RNA polymerase. In some cases, a polymerase is a reverse transcriptase. A reverse transcriptase can synthesize DNA from deoxyribonucleotides. In some cases, a reverse transcriptase adds deoxyribonucleotides to the 3’ end of a nucleic acid primer to synthesize DNA. In some cases, a reverse transcriptase uses an RNA template and uses base-pairing interactions to synthesize a DNA strand that is complementary to the RNA template. The reverse transcriptase domain can be a reverse transcriptase from any organism, phage, virus, or an engineered or mutated variant. The reverse transcriptase domain can be a reverse transcriptase derived from or sharing structural or sequencing similarity to a reverse transcriptase in a CRISPR system. The reverse transcriptase can be an M-MLV or HIV reverse transcriptase. The reverse transcriptase can be a human LINE-1 reverse transcriptase or a group II intron reverse transcriptase. The reverse transcriptase can be a human endogenous retrovirus reverse transcriptase.WSGR Docket No.: 62697-751.601

[0257] In some cases, a nucleic -acid modifying effector or a nucleic acid-binding moiety comprises a transposase domain. A transposase domain can be a natural or an engineered domain. A transposase domain can be capable of aiding the translocation of a transposable element, a nucleic acid sequence that can change its position within a genome. In some cases, a transposase domain comprises a TnsA, a TnsB, a TnsC, or a TnsD domain. In some cases, a transposase domain comprises a TniQ domain. In some cases, a transposase domain is derived from or shares sequence or structural similarity with a transposase in a CRISPR system (e.g., a CRISPR-associated transposase). In some cases, a transposase domain is derived from or share sequence or structural similarity with a transposase domain from a type I CRISPR- associated transposon (CAST) system. In some cases, transposase domain is derived from or share sequence or structural similarity with a transposase domain from a type V CRISPR-associated transposon (CAST) system. A transposase domain can be capable of binding to a guidable polypeptide domain. In some cases, a transposase domain is coupled to a guidable polypeptide domain. In some cases, a transposase domain is capable of binding to a type I CRISPR-Cas domain (e.g., a Cascade domain, a Cas8 domain, or a Cas5 domain). In some cases, a transposase domain is capable of binding to a type V CRISPR-Cas domain (e.g., a Casl2 domain). In some cases, a transposase domain is capable of mediating targeted insertion of a nucleic acid into a target nucleic acid. In some cases, a transposase domain is capable of mediating targeted insertion of a nucleic acid that is at least 5 kb, at least 6 kb, at least 7 kb, at least 8kb, at least 9kb, at least lOkb, at least 1 Ikb, at least 12kb, at least 13kb, at least 14kb, or at least 15 kb into a target nucleic acid.

[0258] In some cases, the payload comprises a transcriptional regulatory domain. A transcriptional regulatory domain can be a natural or an engineered domain. A transcriptional regulatory domain can be capable of regulating, activating, or inhibiting gene expression. For example, a transcriptional repressor can silence gene expression by binding to the promoter of a gene. A transcriptional activator can bind to enhancers or regulatory elements to activate expression of a gene. A transcriptional regulatory domain can comprise a transcription factor. A transcriptional regulatory domain can comprise a transcriptional activation domain or a transcriptional repression domain. For example, a transcriptional activation domain can be or comprise a CAP domain, a VP64 domain, a p65 domain, an Rta domain, a synergistic activation mediator (SAM) domain, a SunTag domain, a VPR domain, a DNA demethylase domain, a histone methyltransferase domain, a histone acetyltransferase domain, or a histone demethylase domain. A transcriptional repression domain can be or comprise a dCas9 domain, a KRAB domain, a Sin3 interacting domain (SID), or a MePC2 domain, a DNA methyltransferase domain, a histone deacetylase domain, a histone methyltransferase domain, or a histone demethylase domain. In some cases, a transcriptional regulatory domain comprises an epigenetic modifying effector domain. For example, an epigenetic modifying effector can be a DNA methyltransferase, a DNA demethylase, a histone methyltransferase, a histone demethylase, a histone acetyltransferase, or a histone deacetylase domain. A DNA methyltransferase domain can be capable of methylating a nucleic acid. A DNA demethylase domain can be capable of demethylating a nucleic acid. A histone methyltransferase domain can be capable of methylating a histone. A histone demethylase domain can be capable of demethylating aWSGR Docket No.: 62697-751.601 histone. A histone acetyltransferase domain can be capable of adding an acetyl group to a histone. A histone deacetylase domain can be capable of removing an acetyl group from a histone.

[0259] In some embodiments, the payload comprises a zinc finger domain. A zinc finger domain can be a natural or an engineered domain. A zinc finger domain can bind to a specific DNA sequence in a target nucleic acid. A zinc finger domain can comprise from 1 to 10, from 2 to 10, from 3 to 10, from 4 to 10, from 5 to 10, from 6 to 10, from 7 to 10, from 8 to 10, from 9 to 10 zinc fingers, from 1 to 8, from 2 to 8, from 3 to 8, from 4 to 8, from 5 to 8, from 6 to 8, from 7 to 8, from 8 to 8, from 9 to 8 zinc fingers. In some cases, a zinc finger domain comprises a two-handed zinc finger domain. A two handed zinc finger domain can comprise two clusters of zinc finger domains that are separated by intervening amino acids. A two handed zinc finger domain can bind to two noncontiguous target DNA sequences. In some cases, the spacing between the two noncontiguous target sequences comprises from 1 to 15, from 1 to 12, from 1 to 10, from 1 to 8, or from 1 to 5 nucleotides. For example, a two handed type of zinc finger binding protein can be SIP1. A cluster of zinc finger domains in a two handed zinc finger domain can be capable of binding to a unique target nucleic acid sequence.

[0260] In some embodiments, the payload comprises a TALE domain. A TALE domain can be a natural or an engineered domain. A TALE domain can bind to a specific DNA sequence. A TALE domain can comprise one or more effector domains. A TALE effector domain can comprise a central repeat domain comprising tandem repeats. A tandem repeat can comprise repeat variable residues (RVD). One or more RVDs can detect a specific DNA base. Different TALE effector domains may have a different number of repeats and a different order of their repeats. The C-terminal repeat is usually shorter in length (e.g., about 20 amino acids). Sequential repeats and their RVDs can recognize sequential DNA bases.

[0261] A TALE domain described herein can be derived from a TALE effector from a bacterial species. The TALE domain can be engineered to target a given nucleic acid sequence based on their DNA base specificities. The TALE domain can be engineered to remove or add a TALE effector domain. In some cases, the TALE domain corresponds to a perfect match to a nucleic acid target sequence. In some cases, the TALE domain of an epigenetic effector corresponds to one or more mismatches to a target base in the target nucleic acid.

[0262] In some cases, the payload in the present disclosure comprises a fusion protein. A fusion protein can comprise two or more polypeptide domains of any of the polypeptide domains described elsewhere herein. A fusion protein can be a natural or an engineered fusion protein. In some cases, the two or more polypeptide domains are coupled together. The two or more polypeptide domains can be coupled together directly or coupled together indirectly. For example, a first polypeptide domain can be coupled directly to a second polypeptide domain. Alternatively, the first polypeptide domain can be coupled indirectly to the second polypeptide domain by coupling with a third polypeptide domain that is coupled directly to the second polypeptide domain. In some cases, a first polypeptide domain is coupled to the N-terminus of a second polypeptide domain. In some cases, a first polypeptide domain is coupled to the C-terminus of a second polypeptide domain. In some cases, a first polypeptide domain is coupled to an internal component of a second polypeptide domain. In some cases, the two or more polypeptide domains areWSGR Docket No.: 62697-751.601 covalently linked. In some cases, the two or more polypeptide domains are noncovalently linked. In some cases, the two or more polypeptide domains are coupled together by a linker. For example, a linker may be a peptide linker. A linker can be a rigid linker, which helps maintain a fixed distance between the polypeptide domains that it links. A linker can be a flexible linker, which can allow some flexibility in movement of one polypeptide domain relative to the other polypeptide domain that it is linked to. In some cases, a linker is a cleavable linker. For example, a cleavable linker can comprise a disulfide bond. Alternatively, a cleavable linker can be an enzymatic cleavable linker, e.g., a linker comprising a protease cleavage site.

[0263] The present disclosure provides fusion proteins comprising a guidable polypeptide domain (e.g., a CRISPR domain). A fusion protein comprising a guidable polypeptide domain (e.g., a CRISPR domain) can comprise one or more of a FokI domain, a deaminase domain, a reverse transcriptase domain, an RNA binding domain, a transcriptional regulatory domain, a plasma membrane recruitment domain, a transmembrane domain, a signaling domain, a receptor domain, a packaging domain, or a targeting domain.

[0264] In some cases, the present disclosure provides a fusion protein comprising a guidable polypeptide domain (e.g., a CRISPR domain) coupled to a deaminase domain. A guidable polypeptide domain (e.g., a CRISPR domain) coupled to a deaminase domain can be used for base editing. A base editor can be capable of editing a nucleic acid sequence in a target nucleic acid molecule. A base editor can be capable of enabling the generation of base conversions or point mutations in a target nucleic acid. For example, a cytosine base editor can comprise a guidable polypeptide domain (e.g., a CRISPR domain) and a cytidine deaminase domain. An adenine base editor can comprise CRISPR domain and an adenosine deaminase domain. In some cases, a base editor enables the conversion of C to G, A to I, or C to U. A cytosine base editor can be capable of enabling the conversion of a C-G base pair to a T-A base pair. An adenine base editor can be capable of enabling the conversion of an A-T base pair to a G-C base pair. In some cases, a base editor comprises a catalytically inactive guidable polypeptide domain (e.g., a CRISPR domain) (e.g., dCas9, dCasl2a, or dCasl3b). In other cases, the base editor comprises a guidable polypeptide nickase domain (e.g., nCas9). In some cases, the base editor enables a base pair conversion without introducing a double-stranded break. In some cases, the base editor enables base pair conversions in a target window. In some cases, the base editor comprises a targeting window of from 1 to 20 bases, from 1 to 19 bases, from 1 to 18 bases, from 1 to 17 bases, from 1 to 16 bases, from 1 to 15 bases, from 1 to 14 bases, from 1 to 13 bases, from 1 to 12 bases, from 1 to 11 bases, from 1 to 10 bases, from 1 to 9 bases, from 1 to 8 bases, from 1 to 7 bases, from 1 to 6 bases, from 1 to 5 bases, from 1 to 4 bases, from 1 to 3 bases, or from 1 to 2 bases. In some cases, a base editor has a targeting window of from 3 to 10 bases, from 3 to 9 bases, from 3 to 8 bases, from 3 to 7 bases, from 3 to 6 bases, from 3 to 5 bases, or from 3 to 4 bases. In some cases, the guidable polypeptide domain (e.g., a CRISPR domain) is coupled to the N-terminus of a deaminase domain. In some cases, the guidable polypeptide domain (e.g., a CRISPR domain) is coupled to the C- terminus of a deaminase domain. In some cases, the guidable polypeptide domain (e.g., a CRISPR domain) is coupled to an internal component of a deaminase domain.WSGR Docket No.: 62697-751.601

[0265] In some cases, the fusion protein comprises a guidable polypeptide domain (e.g., a CRISPR domain) coupled to a reverse transcriptase domain. A guidable polypeptide domain (e.g., a CRISPR domain) coupled to a reverse transcriptase can be capable of enabling prime editing. A prime editor can be capable of editing a nucleic acid sequence in a target nucleic acid molecule. A prime editor can be capable of mediating insertion or deletion of a nucleic acid sequence in a target nucleic acid molecule. In some cases, the prime editor enables a sequence insertion or sequence deletion without introducing a double-stranded break. In some cases, the prime editor introduces a nick at the target site. The prime editor can enable insertion of a template sequence in a target nucleic acid molecule. The template sequence can comprise the desired edit. In some cases, a prime editor reverse transcribes a template sequence to synthesize a complementary strand. In some cases, the synthesized complementary strand is inserted in the target nucleic acid molecule. In some cases, the prime editor uses a primer to carry out reverse transcription. The prime editor can install nucleotides to the 3’ end of a primer strand. In some cases, a primer strand is generated by nicking the target nucleic acid molecule. In some cases, nicking a strand of the target nucleic acid molecule produces a flap with a 3’ OH group. In some cases, the prime editor uses the flap with the 3’ OH group as the primer to carry out reverse transcription. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to the N-terminus of a reverse transcriptase domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to the C-terminus of a reverse transcriptase domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to an internal component of a reverse transcriptase domain.

[0266] In some cases, the fusion protein comprises a guidable polypeptide domain (e.g., a CRISPR domain) coupled to a transcriptional regulatory domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to a transcriptional regulatory domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to a transcriptional activation domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to a transcriptional repression domain. In some cases, guidable polypeptide domain (e.g., a CRISPR domain) is coupled to a transcriptional regulatory domain. A guidable polypeptide domain (e.g., a CRISPR domain) coupled to a transcriptional regulatory domain can be capable of enabling CRISPR interference (CRISPRi) or CRISPR activation (CRISPRa). In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to the C-terminus of a transcriptional regulatory domain. In some cases, a guidable polypeptide domain (e.g., a CRISPR domain) is coupled to an internal component of a transcriptional regulatory domain. Any of the payloads described herein can further comprise a plasma membrane recruitment domain, transmembrane domain, a signaling domain, a receptor domain, a packaging domain, or a targeting domain. Any of payloads described herein can comprise or be engineered to comprise a protein tag, a peptide tag, or small molecule tag. For example, a pay load can comprise a small nuclear localization signal (NLS), a nuclear export signal (NES), a cell penetrating peptide (CPP), a mitochondria penetrating peptide (MPP), a solubility tag, or a fluorescent tag.WSGR Docket No.: 62697-751.601Nucleic acids and polynucleotides

[0267] In some cases, the lipid delivery particle of the present disclosure comprises a payload comprising a nucleic acid. The nucleic acid as a payload can comprise or be composed of one or more nucleotides. Nucleotides are referred to by their commonly accepted single-letter codes: A represents adenine, C represents cytosine, G represents guanine, T represents thymine, U represents uracil, I represents inosine. Unless otherwise indicated, nucleotide sequences are written from left to right in a 5' to 3' orientation. In some cases, the nucleic acid as a payload comprises a polynucleotide. The nucleic acid as a payload can comprise DNA or RNA. In some cases, the nucleic acid as a payload comprises or encodes a gene. The nucleic acid as a payload can comprise or encode any of the polynucleotides described elsewhere herein. The nucleic acid as a payload can be a vector encoding any of the polypeptide domains described elsewhere herein. In some cases, the nucleic acid as a payload is an engineered polynucleotide.

[0268] In some cases, the payload comprises a repair template. The repair template can be doublestranded or single -stranded. The repair template can comprise a template sequence comprising a desired edit to be introduced in a target nucleic acid molecule. In some cases, the repair template is a homology- directed repair template. A homology-directed repair template can comprise a homology arm that is homologous to a sequence in the target nucleic acid. In some cases, the payload comprises a DNA- synthesis template comprising a DNA-synthesis template sequence. The DNA-synthesis template can comprise a desired edit to be introduced in a target nucleic acid molecule. The DNA-synthesis template can be a template for a DNA polymerase or a reverse transcriptase to carry out DNA synthesis. For example, in prime editing, a prime editor can use the DNA synthesis template sequence to synthesize a DNA strand that is complementary to the DNA synthesis template sequence. In some cases, the DNA strand is inserted into the target nucleic acid. In some cases, the nucleic acid comprising the DNA synthesis template sequence also comprises a primer-binding sequence. A primer-binding sequence can be complementary to a sequence in a primer strand to which a DNA polymerase or reverse transcriptase can add nucleotides. In some cases, the primer strand is part of a target nucleic acid molecule. A primerbinding sequence can be complementary to a sequence in the target nucleic acid.

[0269] In some cases, the payload comprises a double -stranded DNA containing a desired gene sequence to be inserted in the target nucleic acid molecule. In some cases, the double -stranded DNA is configured to couple to a transposase domain. In some cases, the payload is delivered in the same particle as the transposase domain. In some cases, the payload is delivered in a separate particle as the transposase domain.

[0270] In some cases, the payload comprises a polynucleotide that is configured to bind to a guidable polypeptide domain. In some cases, the polynucleotide directs a guidable polypeptide domain to a sequence in a target nucleic acid molecule. In some cases, the polynucleotide comprises a scaffold segment configured to bind to a guidable polypeptide domain (e.g., Cas9 or Casl2). In some cases, polynucleotide comprises a spacer sequence that is complementary to a target sequence in the target nucleic acid molecule and is capable of hybridizing to the target sequence. The polynucleotide can be aWSGR Docket No.: 62697-751.601 natural molecule or an engineered or synthetic molecule. The polynucleotide can be derived or share sequence or structural similarities to CRISPR RNA (crRNA), a tracrRNA, or a scoutRNA encoded in a CRISPR system. In some cases, the polynucleotide is engineered to be a single RNA guide (sgRNA) comprising elements of the crRNA and the tracrRNA. In some cases, the polynucleotide comprises a scaffold segment and a spacer sequence. The scaffold segment can be configured to bind to a guidable polypeptide domain. The scaffold segment can be specific to a specific type of guidable polypeptide (e.g., Cas9 or Casl2). In some cases, the spacer sequence is programmed to be any sequence. In some cases, the spacer sequence is programmed to a sequence complementary to a target nucleic acid sequence.

[0271] In some cases, the payload comprises a polynucleotide comprising a scaffold segment, a spacer sequence, a DNA synthesis template, and a primer-binding sequence. In some cases, the scaffold segment and a spacer sequence are on a first nucleic acid molecule and the DNA synthesis template and the primer-binding sequence are on a second nucleic acid molecule.

[0272] In some cases, the payload comprises a polypeptide domain described herein coupled to a polynucleotide domain described herein. In some cases, the payload comprises a polypeptide domain described herein complexed to a polynucleotide domain described herein. In some cases, the payload comprises a ribonucleoprotein. For example, the payload may comprise a guidable polypeptide domain complexed to a polynucleotide configured to bind to the guidable polypeptide domain (e.g., Cas9 complexed with an RNA guide).

[0273] Any of the payloads described herein can further comprise a plasma membrane recruitment element, a transmembrane domain, a signaling domain, a receptor domain, a packaging domain, or a targeting domain. Any of payloads described herein can comprise or be engineered to comprise a protein tag, a peptide tag, or small molecule tag. For example, a payload can comprise a nuclear localization signal (NLS), a nuclear export signal (NES), a cell penetrating peptide (CPP), a mitochondria penetrating peptide (MPP), a solubility tag, a fluorescent tag, or any combinations thereof.Other Payloads

[0274] In some cases, the payload in the lipid delivery particle of the present disclosure comprises a recombinant protein. The payload can be a diagnostic imaging agent, such as a contrast agent. In some cases, the payload comprises a therapeutic agent, including, but not limited to, a nuclease, a recombinase, a growth factor, an antibody, a chimeric antigen receptor, a T cell receptor, a cytokine, a cytokine inhibitor or agonist, a transcription factor, an organelle, a nucleic acid molecule, a therapeutic DNA, a therapeutic RNA, a retrotransposon, a reverse transcriptase, an oligonucleotide, an aptazyme, an aptamer, or a ribozyme, a generic or specific kinase inhibitor, a small molecule drug, an immunomodulator, a tumor suppressor, a developmental regulator, a cancer vaccine, an anesthetic, an enzyme, a hormone, a ligand, a receptor, a T cell receptor, a transposon, a retrotransposon, a DNA polymerase, a RNA dependent DNA polymerase, a homing endonuclease, interferons, chemokines, insulin, growth factors, an antisense oligonucleotide, an RNAi, a shRNA, and any combination thereof. The payload can be a prophylactic agent. In some cases, the payload comprises a biomarker. The payload can also comprise anWSGR Docket No.: 62697-751.601 exogenous antigen or an enzyme. In some cases, the payload comprises a metabolite molecule. In some cases, the payload comprises a lipid molecule. In some cases, the payload comprises a structural protein. In some cases, the payload comprises a hormone or a hormonal protein.

[0275] In some embodiments, the payload comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof.Methods of Delivering Payloads

[0276] Provided herein are methods of delivering a payload to a target cell. In some embodiments, the method comprises contacting a cell with a lipid delivery particle described herein. The cell may be an immune cell, a red blood cell, a white blood cell, an epithelial cell, an endothelial cell, a bone cell, a pancreatic cell, a liver cell (e.g., a hepatocyte), a kidney cell (e.g., a nephron cell), a skin cell (e.g., a keratinocyte), a lung cell (e.g., an alveolar cell), or any combination thereof. In some embodiments, the cell is a progenitor cell. In some embodiments, the lipid delivery particle fuses to a membrane of the cell. In some embodiments, the lipid delivery particle avoids one cell type. In some embodiments, the lipid delivery particle avoids one or more cell types (e.g., 1, 2, 3, 4, 5, or more cell types). The lipid delivery particle may avoid one cell type more than another cell type. In some embodiments, the lipid delivery particles comprising a chimeric envelope protein substantially avoid a certain cell type compared to an otherwise identical lipid delivery particle that does not comprise a chimeric envelope protein. In some embodiments, a lipid delivery particle avoids (e.g., substantially avoid) a hepatocyte.

[0277] In some embodiments, the lipid delivery particle substantially avoids fusing with the membrane of a certain cell type. Avoidance of the cell may lead to a decrease in editing efficiency of a gene locus of the cell after contacting with the lipid delivery particle. For example, if a lipid delivery particle substantially avoids fusing with membrane of a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing that measures a percent of gene edited cells in a group of cells of the same cell type that are contacted with the lipid delivery particles) may be low. The measure of gene editing can be a percent editing, wherein the percentage is a percent of cells comprising the edited gene locus or loci relative to a total number of cells. In some embodiments, if a lipid delivery particle substantially avoids fusing with membrane of a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be at most about 10%, at most about 9%, at most about 8%, at most about 7%, at most about 6%, at most about 5%, at most about 4%, at most about 3%, at most about 2%, at most about 1%, at most about 0.5%, at most about 0.1%, or less than about 0. 1%. In some embodiments, if a lipid delivery particle substantially avoids fusing with membrane of a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be from about 0.1% to about 40%. In some embodiments, if a lipid delivery particle substantially avoids fusing with membrane of a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be from about 0.1% to about 0.5%, about 0.1% to about 1%, about 0.1% to about 2%, about 0. 1% to about 3%, about 0.1% to about 4%, about 0.1% toWSGR Docket No.: 62697-751.601 about 5%, about 0. 1% to about 10%, about 0.5% to about 1%, about 0.5% to about 2%, about 0.5% to about 3%, about 0.5% to about 4%, about 0.5% to about 5%, about 0.5% to about 10%, about 1% to about 2%, about 1% to about 3%, about 1% to about 4%, about 1% to about 5%, about 1% to about 10%, about 2% to about 3%, about 2% to about 4%, about 2% to about 5%, about 2% to about 10%, about 3% to about 4%, about 3% to about 5%, about 3% to about 10%, about 4% to about 5%, about 4% to about 10%, or about 5% to about 10%.

[0278] In some embodiments, a lipid delivery particle described herein avoids delivering a payload to a cell. For example, a lipid delivery particle may substantially avoid delivering a payload into a cell (e.g., a hepatocyte). If a lipid delivery particle substantially avoids delivering a payload into a cell, then a gene locus and / or gene loci of the cell may not be edited. As an example, if the payload of the lipid delivery particle comprises a gene editing agent (e.g., a base editor), and the lipid delivery particle substantially avoids delivering a payload into a cell, then the gene editing agent may not be capable of editing the target gene locus and / or gene loci. If a lipid delivery particle substantially avoids delivering a payload (e.g., gene editing agent) into the cell, then there may be a decrease in an editing efficiency.

[0279] In some embodiments, if a lipid delivery particle substantially avoids delivering a payload (e.g., gene editing agent) into a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be at most about 10%, at most about 9%, at most about 8%, at most about 7%, at most about 6%, at most about 5%, at most about 4%, at most about 3%, at most about 2%, at most about 1%, at most about 0.5%, at most about 0.1%, or less than about 0. 1%. In some embodiments, if a lipid delivery particle substantially avoids delivering a payload (e.g., gene editing agent) into a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be from about 0.1% to about 40%. In some embodiments, if a lipid delivery particle substantially avoids delivering a payload (e.g., gene editing agent) into a cell (e.g., a hepatocyte), then a measure of gene editing (e.g., percent gene editing) may be from about 0.1% to about 0.5%, about 0. 1% to about 1%, about 0.1% to about 2%, about 0. 1% to about 3%, about 0. 1% to about 4%, about 0.1% to about 5%, about 0.1% to about 10%, about 0.5% to about 1%, about 0.5% to about 2%, about 0.5% to about 3%, about 0.5% to about 4%, about 0.5% to about 5%, about 0.5% to about 10%, about 1% to about 2%, about 1% to about 3%, about 1% to about 4%, about 1% to about 5%, about 1% to about 10%, about 2% to about 3%, about 2% to about 4%, about 2% to about 5%, about 2% to about 10%, about 3% to about 4%, about 3% to about 5%, about 3% to about 10%, about 4% to about 5%, about 4% to about 10%, or about 5% to about 10%.PRODUCTION OF LIPID DELIVERY PARTICLES

[0280] In some aspects, provided herein are composition, methods of production, methods of purification related to the lipid delivery particles provided herein. In some cases, the lipid delivery particles can be produced from producer cell lines that are either transiently transfected with at least one plasmid or stably expressing constructs that have been integrated into the producer cell line genomic DNA.

[0281] Producer cell lines can be generated by stably integrating genetic material with a gene of interest into a host cell line. In some cases, the genetic material is transiently expressed in a producer cell line. In some cases, the genetic material is expressed via viral methods. In some cases, the genetic material isWSGR Docket No.: 62697-751.601 expressed via non-viral methods. In some cases, a producer cell line grows in a serum-free medium or in suspension. A producer cell line can be grown in serum-free medium and suspension simultaneously. In some cases, producer cell lines can be generated with adherent cells (e.g., cells cultured in media and attached to a substrate).

[0282] Producer cells can be used to produce the lipid delivery particles described herein. In some cases, generating a producer cell line comprises transfecting cells (e.g., cells of a mammalian cell type) with genetic material of the present disclosure, culturing the cells to produce the lipid delivery particles, obtaining a media from the mammalian cell producing the lipid delivery particles, collecting and filtering the harvested media, and, optionally, purifying the lipid delivery particles to retain structural integrity. In some cases, the method of producing the lipid delivery particle further comprises providing new media to promote transient production of the lipid delivery particles. In some cases, the mammalian cell type includes a HT1080 cell, a COS cell, a HeLa cell, a Chinese Hamster Ovary (CHO) cell, or a HEK 293 cell. HEK293 cells are cells derived from human embryonic kidney cells grown in tissue culture. In some cases, the HEK293 cell is a HEK293, 293E, 293T, 293F, 293FT, or 293T Gesicle cell. The producer cell line can be transformed with a viral vector or non-viral method in any number of means including calcium phosphate and the like.

[0283] Following transfection, the cells can be cultured under conditions for production of lipid delivery particles. Exemplary culturing conditions can include refeeding cells in appropriate media, addition of CO2, and humidity. In some cases, culturing conditions includes addition of antibiotics, anti-fungals, and / or growth factors. The medium can be harvested after 24, 48, 72, or 96 hours, or at any appropriate time point to allow sufficient production of the lipid delivery particles.

[0284] Optionally, the lipid delivery particles in the media can be isolated and collected using any number of techniques known in the art. In some cases, the lipid delivery particles are purified, wherein the lipid delivery particles are washed or resuspended in an appropriate buffer or media or at particular concentration.

[0285] In an aspect, disclosed herein are methods of manufacturing producer cell lines that comprise the lipid delivery particles of the present disclosure. Adherent cells can be first transfected to produce lipid delivery particles. In some cases, transfection occurs by the addition or expression of exogenous nucleic acid sequences via non-viral methods (e.g., by electroporation, microinjection, or a chemical system such as DEAE-dextran or cationic polymers). In some cases, transfection occurs by the addition or expression of exogenous nucleic acid sequences via viral methods (e.g., by infecting the cells with a viral vector, such as an adenoviral vector, adeno-associate viral vector, a lentiviral vector, a herpes viral vector, or a HSV vector). In some cases, the cells are from a HEK293 cell line (e.g., HEK293, 293E, or 293T). In some cases, to transfect DNA into the host cells, the cells are cultured in a medium. In some cases, cells can be cultured in the medium for 5, 10, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25 hours. In some cases, cells can be cultured in the medium for between 10-20 hours. In some cases, cells can be cultured in the medium for 18 hours.WSGR Docket...

Claims

1. WSGR Docket No.: 62697-751.601CLAIMSWHAT IS CLAIMED IS:

1. A lipid delivery particle comprising a lipid membrane encapsulating a cavity and a chimeric envelope protein on the lipid membrane, wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain, wherein the cytoplasmic domain is heterologous to BaEV envelope protein surface unit and is a retrovirus envelope protein cytoplasmic domain, and wherein the cytoplasmic domain is not a MLV envelope protein cytoplasmic domain.

2. A lipid delivery particle comprising a lipid membrane encapsulating a cavity and a chimeric envelope protein on the lipid membrane, wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises a cleavage sequence that is recognizable by a Murine Leukemia Virus (MLV) pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit, and wherein the R peptide is not a MLV envelope protein R peptide.

3. A lipid delivery particle comprising:(a) a lipid membrane encapsulating a cavity;(b) a chimeric envelope protein on the lipid membrane;(c) a chimeric protein within the cavity, wherein the chimeric protein comprises a plasma membrane recruitment element and a payload; wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a cytoplasmic domain, wherein the cytoplasmic domain is heterologous to BaEV envelope protein surface unit and is a retrovirus envelope protein cytoplasmic domain, and wherein the payload comprises a payload protein.

4. A lipid delivery particle comprising:(a) a lipid membrane encapsulating a cavity;(b) a chimeric envelope protein on the lipid membrane;(c) a chimeric protein within the cavity, wherein the chimeric protein comprises a plasma membrane recruitment element and a payload;WSGR Docket No.: 62697-751.601 wherein the chimeric envelope protein comprises a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, and wherein the transmembrane unit comprises:(i) a cleavage sequence that is recognizable by a Murine Leukemia Virus (MEV) pro protein so that cleavage catalyzed by the MEV pro protein releases the R peptide from the transmembrane unit,(ii) a cleavage sequence that is recognizable by a Human Immunodeficiency Virus (HIV) pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit, or(iii) a cleavage sequence that is recognizable by a Feline Leukemia Virus (FeLV) pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit; and wherein the payload comprises a payload protein.

5. The lipid delivery particle of claim 2 or 4, wherein the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide.

6. The lipid delivery particle of claim 1 or 3, wherein the transmembrane unit further comprises a R peptide, wherein the R peptide is not a MLV envelope protein R peptide.

7. The lipid delivery particle of claim 1 or 3, wherein the transmembrane unit further comprises a R peptide, wherein the R peptide is not a HIV envelope protein R peptide.

8. The lipid delivery particle of claim 6 or 7, wherein the transmembrane unit further comprises a cleavage sequence that is recognizable by a MLV pro protein so that cleavage catalyzed by the MLV pro protein releases the R peptide from the transmembrane unit.

9. The lipid delivery particle of claim 6 or 7, wherein the transmembrane unit further comprises a cleavage sequence that is recognizable by a HIV pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit.

10. The lipid delivery particle of claim 6 or 7, wherein the transmembrane unit further comprises a cleavage sequence that is recognizable by a FeLV pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit.

11. The lipid delivery particle of claim 2, 4, and 8-10, wherein the cleavage sequence comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 236-243.

12. The lipid delivery particle of any one of claims 2 and 4-11, wherein the R peptide is a retrovirus envelope protein R peptide.WSGR Docket No.: 62697-751.60113. The lipid delivery particle of any one of claims 2 and 4-12, wherein the R peptide is a gamma retrovirus envelope protein R peptide.

14. The lipid delivery particle of any one of claims 5-13, wherein the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain.

15. The lipid delivery particle of any one of claims 1, 3, and 5-14, wherein the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain.

16. The lipid delivery particle of any one of claims 2 and 4-15, wherein the surface unit and the R peptide are from different species of virus.

17. The lipid delivery particle of any one of claims 1, 3, and 5-16, wherein the surface unit and the cytoplasmic domain are from different species of virus.

18. The lipid delivery particle of any one of claims 5-17, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

19. The lipid delivery particle of any one of claims 5-18, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

20. The lipid delivery particle of any one of claims 2 and 4-19, wherein the R peptide is an MLV envelope protein R peptide.

21. The lipid delivery particle of any one of claims 2 and 4-20, wherein the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO:55.

22. The lipid delivery particle of any one of claims 2 and 4-20, wherein the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO:56.

23. The lipid delivery particle of any one of claims 1, 3, and 5-22, wherein the cytoplasmic domain is an MLV envelope protein cytoplasmic domain.

24. The lipid delivery particle of any one of claims 1-23, wherein the transmembrane domain comprises an MLV envelope protein transmembrane domain.

25. The lipid delivery particle of any one of claims 1, 3, and 5-24, wherein the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 158.

26. The lipid delivery particle of any one of claims 1, 3, and 5-25, wherein the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at leastWSGR Docket No.: 62697-751.60196%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 160.

27. The lipid delivery particle of any one of claims 1-26, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 157.

28. The lipid delivery particle of any one of claims 1-27, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 159.

29. The lipid delivery particle of any one of claims 1-28, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 174.

30. The lipid delivery particle of any one of claims 1-29, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in SEQ ID NO: 190.

31. The lipid delivery particle of any one of claims 2 and 4-19, wherein the R peptide is not an MLV envelope protein R peptide.

32. The lipid delivery particle of any one of claims 2, 4-19, and 31, wherein the cytoplasmic domain is not an MEV envelope protein cytoplasmic domain.

33. The lipid delivery particle of any one of claims 2 and 5-19, wherein the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain.

34. The lipid delivery particle of any one of claims 2, 4-19, and 33, wherein the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide.

35. The lipid delivery particle of any one of claims 5-19, 33, and 34, wherein the cytoplasmic domain and the R peptide comprise:(a) a FeLV envelope protein cytoplasmic domain and a FeLV envelope protein R peptide, respectively;WSGR Docket No.: 62697-751.601(b) a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively;(c) a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or(d) a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively.

36. The lipid delivery particle of any one of claims 1-19 and 33-35, wherein the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope protein transmembrane domain, a KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or a WMSV envelope protein transmembrane domain.

37. The lipid delivery particle of any one of claims 1, 3, 5-19, and 33-36, wherein the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

38. The lipid delivery particle of any one of claims 1, 3, 5-19, and 33-37, wherein the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76.

39. The lipid delivery particle of any one of claims 2, 4-19, and 33-38, wherein the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 57, 59, 250, 254, 258, 262, 266, 270, and 274.

40. The lipid delivery particle of any one of claims 2, 4-19, and 33-39, wherein the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 54, 58, and 60.

41. The lipid delivery particle of any one of claims 1-19 and 33-40, wherein the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115.

42. The lipid delivery particle of any one of claims 1-19 and 33-41, wherein the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, atWSGR Docket No.: 62697-751.601 least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

43. The lipid delivery particle of any one of claims 1-19 and 33-42, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.

44. The lipid delivery particle of any one of claims 1-19 and 33-43, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

45. The lipid delivery particle of any one of claims 1-19 and 33-44, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, 180, 244, 247, 251, 255, 259, 263, 267, and 271.

46. The lipid delivery particle of any one of claims 1-19 and 33-45, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, and 196.

47. The lipid delivery particle of any one of 1-19 and 33-46, wherein the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227.

48. The lipid delivery particle of any one of 1-19 and 33-47, wherein the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.

49. The lipid delivery particle of any one of claims 1-48, wherein the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117.WSGR Docket No.: 62697-751.60150. The lipid delivery particle of any one of claims 1-49, wherein the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118.

51. The lipid delivery particle of any one of claims 1-50, further comprising a viral structural protein.

52. The lipid delivery particle of claim 51, wherein the viral structural protein comprises a gag protein.

53. The lipid delivery particle of claim 51 or 52, wherein the viral structural protein comprises a gag / pro polyprotein.

54. The lipid delivery particle of claim 52, wherein the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type- 1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

55. The lipid delivery particle of claim 53, wherein the gag / pro polyprotein is a gag / pro polyprotein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type-1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

56. The lipid delivery particle of claim 54, wherein the gag protein is a MMLV gag protein.

57. The lipid delivery particle of claim 55, wherein the gag / pro polyprotein is a MMLV gag / pro polyprotein.

58. The lipid delivery particle of claim 52, wherein the viral structural protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1- 48 or 285-305.

59. The lipid delivery particle of claim 52, wherein the viral structural protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

60. The lipid delivery particle of any one of claims 1, 2, and 5-59, further comprising a payload.

61. The lipid delivery particle of claim 60, wherein the payload comprises a payload protein.WSGR Docket No.: 62697-751.60162. The lipid delivery particle of claim 61, furthering comprising a chimeric protein comprising the plasma membrane recruitment element and the payload protein.

63. The lipid delivery particle of any one of claims 3-59 and 62, wherein the plasma membrane recruitment element is fused with the payload protein in order from N-terminus to C-terminus.

64. The lipid delivery particle of claim 62 or 63, wherein the lipid delivery particle comprises a plurality of the chimeric proteins.

65. The lipid delivery particle of any one of claims 62-64, wherein the chimeric protein further comprises a nuclear export signal (NES).

66. The lipid delivery particle of claim 65, wherein the plasma membrane recruitment element, the NES, and the payload protein are arranged in order from N-terminus to C-terminus.

67. The lipid delivery particle of any one of claims 62-66, wherein the chimeric protein further comprises a linker.

68. The lipid delivery particle of claim 67, wherein the linker is a cleavable linker.

69. The lipid delivery particle of claim 68, wherein the cleavable linker is positioned between the plasma membrane recruitment element and the payload protein.

70. The lipid delivery particle of claim 68, wherein the cleavable linker is positioned between the NES and the payload protein.

71. The lipid delivery particle of claim 69 or 70, wherein a nuclear localization signal (NLS) is present at C-terminus of the cleavable linker.

72. The lipid delivery particle of any one of claim 68-71, wherein the chimeric protein comprises, from N-terminus to C-terminus:(a) [the plasma membrane recruitment element]-[the cleavable linker]-[the payload protein];(b) [the plasma membrane recruitment element]- [n* the NES] -[the cleavable linker]-[the payload protein];(c) [the plasma membrane recruitment element]-[the cleavable linker]-[the payload protein]-[n* the NES];(d) [the plasma membrane recruitment element]-[the cleavable linker]-[n* the NES]-[the payload protein];(e) [the plasma membrane recruitment element]-[a first cleavable linker]-[the payload protein]-[a second cleavable linker]-[n* the NES];(f) [the payload protein]-[the cleavable linker]-[n* the NES]-[the plasma membrane recruitment element];(g) [the payload protein]-[n* the NES]- [the cleavable linker]-[the plasma membrane recruitment element];(h) [n* the NES]-[the payload protein]-[the cleavable linker]-[the plasma membrane recruitment element];(i) [n* the NES]-[a first cleavable linker]-[the payload protein]-[a second cleavable linker]-[the plasma membrane recruitment element]; orWSGR Docket No.: 62697-751.601(j) [the payload protein] -[a first cleavable linker] -[the plasma membrane recruitment element]; wherein n represents an integer from 1 to 20.

73. The lipid delivery particle of any one of claims 3-55 and 58-68, wherein at least a plurality of the payload protein present in the lipid delivery particle is free from fusion.

74. The lipid delivery particle of claim 69, wherein the lipid delivery particle further comprises a cleavage product that comprises the plasma membrane recruitment element but not the payload protein.

75. The lipid delivery particle of any one of claims 3-59 and 62-74, wherein the plasma membrane recruitment element comprises a viral structural protein.

76. The lipid delivery particle of claim 75, wherein the viral structural protein comprises a gag protein.

77. The lipid delivery particle of claim 76, wherein the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type- 1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

78. The lipid delivery particle of claim 76, wherein the gag protein is a MMLV gag protein.

79. The lipid delivery particle of claim 76, wherein the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 or 285-305.

80. The lipid delivery particle of claim 76, wherein the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

81. The lipid delivery particle of any one of claims 3-59 and 62-80, wherein the payload protein comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof.

82. The lipid delivery particle of claim 81, wherein the payload protein comprises a guidable polypeptide.

83. The lipid delivery particle of claim 82, wherein the guidable polypeptide is capable of binding to a polynucleotide.

84. The lipid delivery particle of claim 83, wherein the polynucleotide directs the guidable polypeptide to a sequence in a target nucleic acid molecule.WSGR Docket No.: 62697-751.60185. The lipid delivery particle of any one of claims 82-84, wherein the guidable polypeptide is a Cas protein.

86. The lipid delivery particle of claim 85, wherein the Cas protein is a Cas9 protein or a Cas 12 protein.

87. The lipid delivery particle of any one of claims 83-86, wherein the polynucleotide comprises a spacer sequence, wherein the spacer sequence is complementary to a target sequence in the target nucleic acid molecule and wherein the spacer sequence is capable of hybridizing to the target sequence.

88. The lipid delivery particle of any one of claims 83-87, wherein the polynucleotide comprises a CRISPR RNA (crRNA), a tracrRNA, or a scoutRNA encoded in a CRISPR system.

89. The lipid delivery particle of claim 83, wherein the polynucleotide comprises a single RNA guide (sgRNA) comprising the crRNA and the tracrRNA.

90. The lipid delivery particle of any one of claims 1-89, wherein the lipid delivery particle further comprises a targeting moiety, and wherein the chimeric envelope protein is fused with a targeting moiety or the targeting moiety is anchored to the lipid membrane separately from the chimeric envelope protein.

91. The lipid delivery particle of claim 90, wherein the targeting moiety recognizes a specific molecule on the surface of a target cell.

92. The lipid delivery particle of claim 91, wherein the specific molecule is CD 133.

93. The lipid delivery particle of any one of claims 90-92, wherein the targeting moiety is an antibody or an antigen-binding fragment thereof, an antigen-binding fibronectin type III (Fn3) scaffold, a ligand, a cytokine, a chemokine, or a T cell receptor (TCRs).

94. The lipid delivery particle of claim 93, wherein the targeting moiety is the antibody or the antigenbinding fragment thereof, and wherein the antibody or the antigen-binding fragment thereof is a Fab, a Fab', a F(ab')2, Fv fragments, scFv antibody fragments, disulfide-linked Fvs (sdFv), a Fd fragment, a linear antibody, a single domain antibody, a nanobody, or camelid VHH domains.

95. A composition comprising a first nucleic acid sequence encoding a chimeric envelope protein, wherein the chimeric envelope comprises a Baboon Endogenous Retrovirus (BaEV) surface unit and a transmembrane unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises a cleavage sequence recognizable by a Murine Leukemia Virus (MEV) protease so that cleavage catalyzed by the MEV pro protein releases the R peptide from the transmembrane unit, and wherein the R peptide is not a MEV envelope protein R peptide.

96. The composition of claim 95, wherein the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide.

97. The composition of claim 95, wherein the cytoplasmic domain is not a MEV envelope protein cytoplasmic domain.

98. The composition of any one of claims 95-97, wherein the R peptide is a retrovirus envelope protein R peptide.WSGR Docket No.: 62697-751.60199. The composition of claim 95 or 98, wherein the R peptide is a gamma retrovirus envelope protein R peptide.

100. The composition of any one of claims 96-99, wherein the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain.

101. The composition of any one of claims 96-100, wherein the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain.

102. The composition of any one of claims 95-101, wherein the surface unit and the R peptide are from different species of virus.

103. The composition of any one of claims 96-102, wherein the surface unit and the cytoplasmic domain are from different species of virus.

104. The composition of any one of claims 96-103, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

105. The composition of any one of claims 96-104, wherein the surface unit and the cytoplasmic domain are from different species of virus.

106. The composition of any one of claims 95-105, wherein the surface unit and the R peptide are from different species of virus.

107. The composition of any one of claims 96-106, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

108. The composition of any one of claims 96-107, wherein the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain.

109. The composition of any one of claims 95-108, wherein the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide.

110. The composition of any one of claims 96-109, wherein the cytoplasmic domain and the R peptide comprise:(a) a FeLV envelope protein cytoplasmic domain and a FeLV envelope protein R peptide, respectively;(b) a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively;(c) a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or(d) a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively.

111. The composition of any one of claims 95-110, wherein the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope protein transmembrane domain, aWSGR Docket No.: 62697-751.601KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or aWMSV envelope protein transmembrane domain.

112. The composition of any one of claims 96-111, wherein the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

113. The composition of any one of claims 96-112, wherein the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76.

114. The composition of any one of claims 95-113, wherein the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51,53, 57, 59, 250, 254, 258, 262, 266, 270, and 274.

115. The composition of any one of claims 95-114, wherein the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52,54, 58, and 60.

116. The composition of any one of claims 95-115, wherein the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117.

117. The composition of any one of claims 95-116, wherein the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118.

118. The composition of any one of claims 95-117, wherein the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115.

119. The composition of any one of claims 95-118, wherein the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at leastWSGR Docket No.: 62697-751.60197%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

120. The composition of any one of claims 95-119, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.

121. The composition of any one of claims 95-120, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

122. The composition of any one of claims 95-121, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, 180, 244, 247, 251, 255, 259, 263, 267, and 271.

123. The composition of any one of claims 95-122, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, 196, 275, 277, 279, 281, 282, 284, 286, 288.

124. The composition of any one of 95-123, wherein the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227.

125. The composition of any one of 95-124, wherein the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.

126. The composition of any one of claims 95-125, further comprising a second nucleic acid sequence encoding a plasma membrane recruitment element.

127. The composition of claim 126, wherein the plasma membrane recruitment element comprises a viral structural protein.

128. The composition of claim 126 or 127, wherein the plasma membrane recruitment element comprises a gag protein.WSGR Docket No.: 62697-751.601129. The composition of claim 126 or 127, wherein the plasma membrane recruitment element comprises a gag / pro polyprotein.

130. The composition of claim 128, wherein the gag protein is a gag protein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type- 1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

131. The composition of claim 129, wherein the gag / pro protein is a gag / pro polyprotein from human immunodeficiency virus (HIV), murine leukemia virus (MLV), Moloney murine leukemia virus (MMLV), Friend murine leukemia virus (FMLV), Baboon endogenous retrovirus (BaEV), Simian immunodeficiency virus (SIV), Rous sarcoma virus (RSV), human T-cell leukemia virus type- 1 (HTLV), bovine leukemia virus (BLV), Feline Leukemia Virus (FeLV), Gibbon Ape Leukemia Virus (GaLV), Koala Retrovirus (KRV), Reticuloendotheliosis Virus (ReEV), Wooly Monkey Sarcoma Virus (WMSV), or a biologically active mutant thereof, or any combination thereof.

132. The composition of claim 130, wherein the gag protein is a MMLV gag protein.

133. The composition of claim 131, wherein the gag / pro polyprotein is a MMLV gag / pro polyprotein.

134. The composition of any one of claims 126-131, wherein the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 1-48 or 285-305.

135. The composition of any one of claims 126-131, wherein the plasma membrane recruitment element comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 197-219.

136. The composition of any one of claims 95-135, further comprising a third nucleic acid sequence encoding a payload.

137. The composition of claim 136, wherein the payload comprises a payload protein.

138. The composition of claim 137, wherein the payload protein comprises a nuclease, a base editor, a prime editor, an epigenetic editor, a restriction endonuclease, a recombinase, a transcription factor, an antibody, a chimeric antigen receptor, a T cell receptor, an organelle, a retrotransposon, a reverse transcriptase, or any combination thereof.

139. The composition of any one of claims 128-138, wherein the payload comprises a guidable polypeptide.WSGR Docket No.: 62697-751.601140. The composition of claim 139, wherein the guidable polypeptide is capable of binding to a polynucleotide.

141. The composition of claim 140, wherein the polynucleotide directs the guidable polypeptide to a sequence in a target nucleic acid molecule.

142. The composition of any one of claims 139-141, wherein the guidable polypeptide is a Cas protein.

143. The composition of claim 142, wherein the Cas protein is a Cas9 protein or a Cas 12 protein.

144. The composition of any one of claims 140-143, wherein the polynucleotide comprises a spacer sequence, wherein the spacer sequence is complementary to a target sequence in the target nucleic acid molecule and wherein the spacer sequence is capable of hybridizing to the target sequence.

145. The composition of any one of claims 140-144, wherein the polynucleotide comprises a CRISPR RNA (crRNA), a tracrRNA, or a scoutRNA encoded in a CRISPR system.

146. The composition of claim 145, wherein the polynucleotide comprises a single RNA guide (sgRNA) comprising the crRNA and the tracrRNA.

147. The composition of any one of claims 137-146, further comprising a fourth nucleic acid sequence encoding a nuclear export signal (NES).

148. The composition of claim 147, wherein the second nucleic acid sequence, the fourth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5’ to 3’.

149. The composition of 147 or 148, further comprising a fifth nucleic acid sequence encoding a linker.

150. The composition of claim 149, wherein the linker is a cleavable linker.

151. The composition of claim 150, wherein the second nucleic acid sequence, the fifth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5’ to 3’.

152. The composition of claim 150, wherein the second nucleic acid sequence, the fourth nucleic acid sequence, and the third nucleic acid sequence are arranged in order from 5’ to 3’.

153. The composition of any one of claims 149-152, further comprising a sixth nucleic acid sequence encoding a nuclear localization signal (NLS).

154. The composition of claim 153, wherein the fifth nucleic acid sequence and the sixth nucleic acid sequence are arranged in order from 5’ to 3’.

155. The composition of any one of claims 95-154, further comprising a seventh nucleic acid sequence encoding a targeting moiety.

156. The composition of claim 155, wherein the targeting moiety recognizes a specific molecule on the surface of a target cell.

157. The composition of claim 156, wherein the specific molecule is CD 133.

158. The composition of any one of claims 155-157, wherein the targeting moiety is an antibody or an antigen-binding fragment thereof, an antigen-binding fibronectin type III (Fn3) scaffold, a ligand, a cytokine, a chemokine, or a T cell receptor (TCRs).WSGR Docket No.: 62697-751.601159. The composition of claim 158, wherein the targeting moiety is the antibody or the antigenbinding fragment thereof, and wherein the antibody or the antigen-binding fragment thereof is a Fab, a Fab', a F(ab')2, Fv fragments, scFv antibody fragments, disulfide-linked Fvs (sdFv), a Fd fragment, a linear antibody, a single domain antibody, a nanobody, or camelid VHH domains.

160. A composition comprising nucleic acid sequences encoding proteins capable of forming the lipid delivery particle of any one of claims 1-94 when the nucleic acid sequences are expressed in a producer cell.

161. A chimeric protein comprising a surface unit and a transmembrane unit, wherein the surface unit comprises a Baboon Endogenous Retrovirus (BaEV) envelope protein surface unit, wherein the transmembrane unit comprises a transmembrane domain and a R peptide, wherein the transmembrane unit comprises:(a) a cleavage sequence recognizable by a Murine Leukemia Virus (MEV) pro protein so that cleavage catalyzed by the MEV pro protein releases the R peptide from the transmembrane unit,(b) a cleavage sequence recognizable by a Human Immunodeficiency Virus (HIV) pro protein so that cleavage catalyzed by the HIV pro protein releases the R peptide from the transmembrane unit, or(c) a cleavage sequence recognizable by a Feline Leukemia Virus (FeLV) pro protein so that cleavage catalyzed by the FeLV pro protein releases the R peptide from the transmembrane unit; and wherein the R peptide is not a MLV envelope protein R peptide or a HIV envelope protein R peptide.

162. The chimeric protein of claim 161, wherein the surface unit and the R peptide are associated by noncovalent interactions or by disulfide bonds.

163. The chimeric protein of claim 161 or 162, wherein the cleavage sequence comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 236-243.

164. The chimeric protein of any one of claims 161-163, wherein the transmembrane unit further comprises a cytoplasmic domain operably linked between the transmembrane domain and the R peptide.

165. The chimeric protein of claim 163, wherein the cytoplasmic domain is not a MLV envelope protein cytoplasmic domain.

166. The chimeric protein of claim 163, wherein the cytoplasmic domain is not a HIV envelope protein cytoplasmic domain.

167. The chimeric protein of any one of claims 161-166, wherein the R peptide is a retrovirus envelope protein R peptide.WSGR Docket No.: 62697-751.601168. The chimeric protein of any one of claims 161-167, wherein the R peptide is a gamma retrovirus envelope protein R peptide.

169. The chimeric protein of any one of claims 162-168, wherein the cytoplasmic domain is a retrovirus envelope protein cytoplasmic domain.

170. The chimeric protein of any one of claims 161-169, wherein the cytoplasmic domain is a gamma retrovirus envelope protein cytoplasmic domain.

171. The chimeric protein of any one of claims 161-170, wherein the surface unit and the R peptide are from different species of virus.

172. The chimeric protein of any one of claims 161-171, wherein the surface unit and the cytoplasmic domain are from different species of virus.

173. The chimeric protein of any one of claims 161-172, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

174. The chimeric protein of any one of claims 162-173, wherein the surface unit and the cytoplasmic domain are from different species of virus.

175. The chimeric protein of any one of claims 161-174, wherein the surface unit and the R peptide are from different species of virus.

176. The chimeric protein of any one of claims 162-175, wherein the cytoplasmic domain and the R peptide are from the same species of virus.

177. The chimeric protein of any one of claims 162-176, wherein the cytoplasmic domain comprises a Feline Leukemia Virus (FeLV) envelope protein cytoplasmic domain, a Koala Retrovirus (KRV) envelope protein cytoplasmic domain, a Reticuloendotheliosis Virus (ReEV) envelope protein cytoplasmic domain, or a Wooly Monkey Sarcoma Virus (WMSV) envelope protein cytoplasmic domain.

178. The chimeric protein of any one of claims 161-177, wherein the R peptide comprises a FeLV envelope protein R peptide, a KRV envelope protein R peptide, a ReEV envelope protein R peptide, or a WMSV envelope protein R peptide.

179. The chimeric protein of any one of claims 162-178, wherein the cytoplasmic domain and the R peptide comprise:(a) a FeLV envelope protein cytoplasmic domain and a FeLV envelope protein R peptide, respectively;(b) a KRV envelope protein cytoplasmic domain and a KRV envelope protein R peptide, respectively;(c) a ReEV envelope protein cytoplasmic domain and a ReEV envelope protein R peptide, respectively; or(d) a WMSV envelope protein cytoplasmic domain and a WMSV envelope protein R peptide, respectively.

180. The chimeric protein of any one of claims 161-179, wherein the transmembrane domain comprises a BaEV envelope protein transmembrane domain, a FeLV envelope proteinWSGR Docket No.: 62697-751.601 transmembrane domain, a KRV envelope protein transmembrane domain, a ReEV envelope protein transmembrane domain, or aWMSV envelope protein transmembrane domain.

181. The chimeric protein of any one of claims 162-180, wherein the cytoplasmic domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 63, 69, 71, 75, 246, 249, 253, 257, 261, 265, 269, and 273.

182. The chimeric protein of any one of claims 162-181, wherein the cytoplasmic domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 64, 70, 72, and 76.

183. The chimeric protein of any one of claims 161-182, wherein the R peptide comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 51, 53, 57, 59, 250, 254, 258, 262, 266, 270, and 274.

184. The chimeric protein of any one of claims 161-183, wherein the R peptide is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 52, 54, 58, and 60.

185. The chimeric protein of any one of claims 161-184, wherein the surface unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 117.

186. The chimeric protein of any one of claims 161-185, wherein the surface unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to SEQ ID NO: 118.

187. The chimeric protein of any one of claims 161-186, wherein the transmembrane domain comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 79, 81, 105, 107, 111, 113, and 115.

188. The chimeric protein of any one of claims 161-187, wherein the transmembrane domain is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at leastWSGR Docket No.: 62697-751.60196%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 78, 80, 82, 106, 108, 112, 114, and 116.

189. The chimeric protein of any one of claims 161-188, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 153, 155, 161, 163, 245, 248, 252, 256, 260, 264, 268, and 272.

190. The chimeric protein of any one of claims 161-189, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 154, 156, 162, 164, 276, 278, 280, 283, 285, 287, 289, and 290.

191. The chimeric protein of any one of claims 161-190, wherein the transmembrane unit comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 166, 167, 172, 173, 175, 176, 179, and 180.

192. The chimeric protein of any one of claims 161-191, wherein the transmembrane unit is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 181, 182, 183, 188, 189, 191, 192, 195, 196, 275, 277, 279, 281, 282, 284, 286, 288.

193. The chimeric protein of any one of 161-192, wherein the chimeric envelope protein comprises an amino acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 121, 123, 129, 133, 135, 139, 141, 147, 149, and 220-227.

194. The chimeric protein of any one of 161-193, wherein the chimeric envelope protein is encoded by a nucleic acid sequence having at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to a sequence set forth in any one of SEQ ID NOs: 122, 124, 128, 134, 136, 140, 142, 146, 148, 150 and 228-235.

195. A vector comprising the composition of any one of claims 95-160.

196. A cell comprising the composition of any one of claims 95-160 or the vector of claim 195.

197. A pharmaceutical composition comprising the lipid delivery particle of any one of claims 1-94, the composition of any one of claims 95-160, the vector of claim 195, or the cell of claim 196, and a pharmaceutically acceptable excipient, diluent, or vehicle.WSGR Docket No.: 62697-751.601198. A kit comprising the lipid delivery particle of any one of claims 1-94, the composition of any one of claims 91-156, the vector of claim 195, the cell of claim 196, or the pharmaceutical composition of claim 191, and an information material.

199. A method of producing the lipid delivery particle of any one of claims 1-94, the method comprising providing a producer cell comprising a nucleic acid molecule encoding proteins capable of forming the lipid delivery particle, and using the producer cell to produce the lipid delivery particle of any one of claims 1-94.

200. A method of producing the lipid delivery particle of any one of claims 1-94, the method comprising providing the composition of any one of claims 95-160, and using the producer cell to produce the lipid delivery particle of any one of claims 1-94.

201. A method of treating a disease in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of the lipid delivery particle of any one of claims 1- 90, the composition of any one of claims 95-160, the vector of claim 195, the cell of claim 196, or the pharmaceutical composition of claim 197, thereby treating the disease in the subject.

202. A method of editing a nucleic acid molecule in a cell, the method comprising contacting a cell with the lipid delivery particle of any one of claims 1-94.

203. A method of delivering a payload to a target cell, the method comprising contacting a cell with the lipid delivery particle of any one of claims 1-94.

204. The method of any one of claims 201-203, wherein the lipid delivery particle substantially avoids fusing with membrane of hepatocytes.

205. The method of any one of claims 201-203, wherein the lipid delivery particle substantially avoids delivering a payload of the lipid delivery particle into hepatocytes.

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