Function-enhanced cell therapy

Abstract

Provided is an engineered cell that expresses an exogenous immunosuppressive molecule and down-regulates expression of at least one endogenous gene selected from the following: Fas, TNFR1, DR3, DR4, DR5, TGFBR1 and TGFBR2. Also provided are the engineered cell and a composition comprising the cell.

Description

Function-enhanced cell therapy

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number CN2023100961489, entitled “Function-enhanced cell therapy,” filed with the Patent Office of China on February 10, 2023, the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0003] The present invention belongs to the field of immunotherapy. Specifically, the present invention relates to engineered cells and compositions comprising the cells that enhance efficacy and reduce rejection risk by downregulating the expression of certain specific endogenous genes and simultaneously expressing immunosuppressive molecules. Background Art

[0004] As an emerging immunotherapy, adoptive cell therapy has developed very rapidly in recent years. In particular, chimeric antigen receptor therapy has a number of products on the market and has shown excellent therapeutic effects in clinical practice. However, the products currently on the market are all autologous therapies, which have disadvantages such as long preparation time, high cost, and high preparation failure rate. In response to this, allogeneic cell therapy has been developed to improve patient accessibility. However, allogeneic cell therapy also faces a series of challenges, such as the risk of immune rejection and poor cell persistence. Therefore, there is still a need to improve existing allogeneic cell therapies to reduce the risk of immune rejection and enhance cell persistence.

[0005] Summary of the Invention

[0006] Unless otherwise defined, all scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0007] In a first aspect, the present invention provides an engineered cell having the following characteristics: (i) the expression of at least one endogenous gene selected from the group consisting of Fas, TNFR1, DR3, DR4, DR5, TGFBR1, TGFBR2 is downregulated; and (ii) an exogenous immunosuppressive molecule is expressed, wherein the immunosuppressive molecule comprises one or more immunosuppressive protein binding domains, a transmembrane domain, and a co-stimulatory domain and does not comprise a primary signaling domain, wherein the immunosuppressive protein binding domain binds to an immunosuppressive protein selected from the group consisting of PD1, NKG2A, FasL, and CTLA4.

[0008] Downregulate endogenous gene expression

[0009] The engineered cells provided by the present invention have expression of at least one endogenous gene downregulated, wherein the endogenous gene is selected from Fas, TNFR1, DR3, DR4, DR5, TGFBR1 and TGFBR2.

[0010] Fas, TNFR1, DR3, DR4 and DR5 all belong to the death receptor (DR) family and share a Cys-rich extracellular domain and an intracellular death domain (DD). When these death receptors bind to their specific death ligands, they receive extracellular death signals, activate the apoptotic mechanism within the cell, and induce apoptosis. TGFBR1 and TGFBR2 are both receptors for TRFb1, and their intracellular regions contain serine / threonine kinase activity. They mediate Smad-dependent and -independent signaling pathways and play an important regulatory role in processes such as cell proliferation, differentiation, wound healing, and tumorigenesis and metastasis. The inventors have discovered that reducing the expression of these endogenous genes in cells can significantly prolong the persistence of cells and improve cell survival.

[0011] As used herein, gene expression is “downregulated” means that the expression level of the product of the modified gene decreases significantly or is hardly expressed relative to the expression level of the unmodified wild-type gene. This means that for the gene whose expression is “downregulated”, the content of its expression product (such as mRNA or protein) is reduced or the expression product is not functional. Therefore, downregulation can be achieved in different dimensions such as gene level, transcription level, translation level. Generally, gene expression is downregulated by methods well known to those skilled in the art, including but not limited to, for example, by technologies such as meganucleases, zinc finger nucleases, TALEN, CRISPR / Cas systems, base editors, lead editors, etc. to knock down or knock out the target gene itself or the regulatory gene of the target gene, or by technologies such as antisense oligonucleotides, RNAi, shRNA, transposons, siRNA, antigomer RNA, mutations, antibodies or chemical inhibitors to reduce the expression level of the target gene itself or the regulatory gene of the target gene.

[0012] Immunosuppressive molecules

[0013] The engineered cells provided by the present invention also express exogenous immunosuppressive molecules, wherein the immunosuppressive molecules comprise one or more immunosuppressive protein binding domains, transmembrane domains, and co-stimulatory domains and do not comprise a primary signaling domain, wherein the immunosuppressive protein binding domain binds to an immunosuppressive protein selected from the group consisting of PD1, NKG2A, FasL, and CTLA4.

[0014] As used herein, the term "immunosuppressive molecule" refers to a molecule that can bind to immunosuppressive proteins (e.g., PD1, NKG2A) and thereby inhibit the subject's immune rejection of foreign cells, such as reducing the killing function of immune cells (e.g., T cells, NK cells) in the subject's body or inhibiting the excessive proliferation of immune cells.

[0015] In one embodiment, the immunosuppressive protein binding domain is an antibody or ligand that specifically binds to an immunosuppressive protein. In one embodiment, the immunosuppressive protein binding domain comprises an anti-PD1 antibody, an anti-NKG2A antibody, an anti-FasL antibody, an anti-CTLA4 antibody, a PDL1 extracellular region, a PDL2 extracellular region, an HLA-E extracellular region, a Fas extracellular region, a CD80 extracellular region, a CD86 extracellular region, or a combination thereof.

[0016] As used herein, the term "antibody" has the broadest meaning understood by those skilled in the art, and includes monoclonal antibodies (including complete antibodies), polyclonal antibodies, multivalent antibodies, multispecific antibodies (such as bispecific antibodies) and antibody fragments or synthetic polypeptides carrying one or more CDR sequences that can exhibit desired biological activity. The antibodies of the present invention can be of any kind (such as IgG, IgE, IgM, IgD, IgA, etc.) or subclass (such as IgG1, IgG2, IgG2a, IgG3, IgG4, IgA1, IgA2, etc.). As used herein, the term "antibody fragment" refers to one or more fragments of an antibody that retains the ability to specifically bind to an antigen. It has been shown that the antigen-binding function of an antibody can be achieved by fragments of a full-length antibody. Examples of antibody fragments in the present invention include, but are not limited to, Fab, Fab', F(ab')2, Fd fragment, Fd', Fv fragment, single-chain antibody (scFv), disulfide bond-linked Fv (sdFv), heavy chain variable region (VH) or light chain variable region (VL) of an antibody, linear antibodies, "diabodies" with two antigen binding sites, single domain antibodies (sdAb), nanobodies, etc. Therefore, unless the context clearly indicates otherwise, the "antibody" of the present invention encompasses antibody fragments as defined above. Therefore, in a preferred embodiment, the antibody of the present invention is selected from IgG, Fab, Fab', F(ab')2, Fd, Fd', Fv, scFv, sdFv, linear antibodies, diabodies, sdAb or nanobodies, preferably scFv, sdAb or nanobodies.

[0017] Typically, a complete antibody consists of two heavy chains and two light chains linked together by disulfide bonds. Each light chain is connected to its own heavy chain by disulfide bonds, forming a "Y"-shaped structure. Each heavy chain comprises a heavy chain variable region (VH), which contains three complementarity-determining regions (CDRs): CDR1-H, CDR2-H, and CDR3-H, and a heavy chain constant region, which contains three constant domains: CH1, CH2, and CH3. Each light chain comprises a light chain variable region (VL), which contains three CDRs: CDR1-L, CDR2-L, and CDR3-L, and a light chain constant region, which contains one constant domain, CL. Within the heavy and light chain variable regions, the CDRs are separated by more conserved framework regions (FRs). The variable regions of the heavy and light chains are responsible for antigen recognition and binding, while the constant regions mediate the binding of the antibody to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component of the classical complement system.

[0018] The precise amino acid sequence boundaries of a given CDR or FR can be readily determined using a number of numbering schemes well known in the art, including: Kabat et al. (1991), "Sequences of Proteins of Immunological Interest," 5th ed. Public Health Service, National Institutes of Health, Bethesda, Maryland ("Kabat" numbering scheme); Al-Lazikani et al., (1997) JMB 273, 927-948 ("Chothia" numbering scheme); MacCallum et al., J. Mol. Biol. 262:732-745 (1996), "Antibody-antigen interactions: Contact analysis and binding sitetopography," J. Mol. Biol. 262, 732-745 ("Contact" numbering scheme); Lefranc MP et al., "IMGTunique numbering for immunoglobulin and T cell receptor variable domains and Ig superfamily V-like domains," Dev Comp Immunol, 2003 Jan;27(1):55-77 (“IMGT” numbering scheme); Honegger A and Plückthun A, “Yet another numbering scheme for immunoglobulin variable domains: an automatic modeling and analysis tool,” J Mol Biol, 2001 Jun 8;309(3):657-70 (“Aho” numbering scheme); and Martin et al., “Modeling antibody hypervariable loops: a combined algorithm,” PNAS, 1989, 86(23):9268-9272 (“AbM” numbering scheme).

[0019] In some embodiments, the boundary of CDR or FR is different depending on the scheme used to define CDR or FR. For example, the Kabat scheme is based on structural alignment, and the Chothia scheme is based on structural information. The numbering of Kabat and Chothia schemes is all based on the most common antibody region sequence length, wherein insertion (such as "30a") is provided by inserting letters and disappearance occurs in some antibodies. These two schemes are placed in different positions with certain insertions and deletions (indel), thereby producing different numbering. The Contact scheme is based on the analysis of complex crystal structure, and is similar to the Chothia numbering scheme in many aspects. The AbM scheme is a compromise between Kabat and Chothia definitions, and it is based on the scheme used by the AbM antibody modeling software of Oxford Molecular.

[0020] Therefore, unless otherwise specified, it should be understood that the "CDR" of a given antibody or its region (such as its variable region) covers the CDR defined by any of the above schemes or other known schemes. For example, when specifying that a specific CDR (such as CDR3) contains a given amino acid sequence, it should be understood that such CDR can also have the sequence of the corresponding CDR (such as CDR3) defined by any of the above schemes or other known schemes. Similarly, unless otherwise specified, it should be understood that the FR of a given antibody or its region (such as its variable region) covers the FR defined by any of the above schemes or other known schemes. Unless otherwise specified, the numbering scheme used to define the boundaries of CDR and FR in this article adopts the Chothia scheme.

[0021] In one embodiment, the antibody of the invention is a murine antibody, a chimeric antibody, a camelid antibody, a humanized antibody, or a human antibody.

[0022] In one embodiment, the immunosuppressive protein binding domain of the present invention is an antibody targeting PD1. PD1 is a type I transmembrane protein composed of 288 amino acids, including an extracellular IgV domain, a transmembrane region, and an intracellular region, the intracellular region of which contains an immunoreceptor tyrosine-based inhibitory motif (ITIM). PD-1 is expressed on the surface of activated T cells, B cells, and macrophages, and is widely involved in the negative regulation of the body's immune response. PD1 upregulates E3-ubiquitin ligases CBL-b and c-CBL by binding to its ligands (such as PDL1 or PDL2), triggering downregulation of T cell receptors, inhibiting T cell activation and cytokine release. Studies have found that immune regulation targeting PD-1 is of great significance for anti-tumor, anti-infection, anti-autoimmune diseases, and organ transplant survival.

[0023] Any anti-PD1 antibody known in the art can be used in the present invention. In one embodiment, the antibody targeting PD1 comprises a light chain variable region and a heavy chain variable region, wherein the CDR1-L, CDR2-L, and CDR3-L contained in the light chain variable region are identical to the CDR1-L, CDR2-L, and CDR3-L contained in SEQ ID NO: 51; wherein the CDR1-H, CDR2-H, and CDR3-H contained in the heavy chain variable region are identical to the CDR1-H, CDR2-H, and CDR3-H contained in SEQ ID NO: 50. In one embodiment, the CDR1-L contained in the light chain variable region is as shown in SEQ ID NO: 47, the CDR2-L is as shown in SEQ ID NO: 48, and the CDR3-L is as shown in SEQ ID NO: 49; the CDR1-H contained in the heavy chain variable region is as shown in SEQ ID NO: 44, the CDR2-H is as shown in SEQ ID NO: 45, and the CDR3-H is as shown in SEQ ID NO: 46.

[0024] In one embodiment, the antibody targeting PD1 comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region is 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% identical to SEQ ID NO: 51, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 51; wherein the heavy chain variable region is 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% identical to SEQ ID NO: 50, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: The present invention also provides an antibody that has one or more (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 50. Preferably, the modifications are conservative modifications, such as conservative substitutions, additions, and deletions of amino acids. In a preferred embodiment, the anti-PD1 antibody of the present invention comprises a heavy chain variable region as set forth in SEQ ID NO: 50 and a light chain variable region as set forth in SEQ ID NO: 51.

[0025] In one embodiment, the antibody targeting PD1 is 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% identical to SEQ ID NO: 52, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 9 or 14. Preferably, the antibody targeting PD1 is as shown in SEQ ID NO: 52.

[0026] In one embodiment, the immunosuppressive protein binding domain contained in the immunosuppressive molecule of the present invention is the extracellular region of the PD1 ligand, such as the extracellular region of PDL1 or PDL2. In this embodiment, the immunosuppressive molecule may also contain the corresponding transmembrane region of PDL1 or PDL2, but generally does not also contain the corresponding intracellular region. That is, the immunosuppressive molecule is not the full-length PDL1 or PDL2. In this embodiment, the immunosuppressive molecule may also contain a PDL1 signal peptide or a PDL2 signal peptide.

[0027] In one embodiment, the extracellular region of PDL1 is 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% identical to SEQ ID NO:55; the extracellular region of PDL2 is 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% identical to SEQ ID NO:58. The transmembrane region of the PDL1 is 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% identical to SEQ ID NO: 54; the transmembrane region of the PDL2 is 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% identical to SEQ ID NO: 57. The PDL1 signal peptide is 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% identical to SEQ ID NO:53; the PDL2 signal peptide is 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% identical to SEQ ID NO:56.

[0028] In one embodiment, the immunosuppressive protein binding domain included in the immunosuppressive molecule of the present invention is an antibody targeting NKG2A. NKG2A is primarily expressed on NK cells and some T cells (CD8+ T cells, Th2 cells, and NKT cells). NKG2A forms a dimeric complex with CD94 and is recognized by its ligand HLA-E (a non-classical HLA-I class molecule). It recruits SHP1 or SHP-2 through two ITIMs in the cytoplasmic tail, thereby inducing inhibitory signals and inhibiting NK cell cytotoxic activity and cytokine secretion. Anti-NKG2A antibodies known in the art can be used in the present invention, such as Z270 (available from Immunotech, France), Z199 (available from Beckman Coulter, USA), 20D5 (available from BD Biosciences Pharmingen, USA), P25 (available from Moretta et al., Univ. Genova, Italy), and the like.

[0029] In one embodiment, an antibody targeting NKG2A comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region comprises CDR1-L, CDR2-L, and CDR3-L identical to CDR1-L, CDR2-L, and CDR3-L contained in SEQ ID NO: 40; and wherein the heavy chain variable region comprises CDR1-H, CDR2-H, and CDR3-H identical to CDR1-H, CDR2-H, and CDR3-H contained in SEQ ID NO: 39. In one embodiment, the light chain variable region comprises CDR1-L as set forth in SEQ ID NO: 36, CDR2-L as set forth in SEQ ID NO: 37, and CDR3-L as set forth in SEQ ID NO: 38; and the heavy chain variable region comprises CDR1-H as set forth in SEQ ID NO: 33, CDR2-H as set forth in SEQ ID NO: 34, and CDR3-H as set forth in SEQ ID NO: 35.

[0030] In one embodiment, the antibody targeting NKG2A comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region is 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% identical to SEQ ID NO: 40, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 40; wherein the heavy chain variable region is 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% identical to SEQ ID NO: 39, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 39. The invention also provides an anti-NKG2A antibody comprising a heavy chain variable region as set forth in SEQ ID NO: 39 and a light chain variable region as set forth in SEQ ID NO: 40.

[0031] In one embodiment, the antibody targeting NKG2A is 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% identical to SEQ ID NO: 41, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 58. Preferably, the antibody targeting NKG2A is as shown in SEQ ID NO: 41.

[0032] In one embodiment, the immunosuppressive protein binding domain of the present invention comprises an extracellular region of an NKG2A ligand, such as an extracellular region of HLA-E. In one embodiment, the HLA-E extracellular region is 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% identical to SEQ ID NO: 42 or 43. In this embodiment, the immunosuppressive molecule may also comprise the corresponding transmembrane region of HLA-E, but generally does not also comprise its corresponding intracellular region. That is, the immunosuppressive molecule is not full-length HLA-E.

[0033] In one embodiment, the immunosuppressive protein binding domain of the present invention is an antibody targeting FasL. FasL is a type II cell membrane surface glycoprotein and a member of the tumor necrosis factor receptor superfamily (TNFRSF). FasL is distributed on the surface of activated T lymphocytes, NK cells, monocytes and macrophages, and its ligand is Fas. It has been found that the Fas / FasL system is one of the important pathways of cell apoptosis. Specifically, the binding of FasL to Fas forms a death-inducing complex, which in turn activates the caspase signaling pathway, ultimately leading to cell apoptosis through its intracellular tyrosine and serine phosphorylation.

[0034] Any anti-FasL antibody known in the art can be used in the present invention. In one embodiment, the antibody targeting FasL comprises a light chain variable region and a heavy chain variable region, wherein the CDR1-L, CDR2-L, and CDR3-L comprised in the light chain variable region are identical to the CDR1-L, CDR2-L, and CDR3-L comprised in SEQ ID NO: 66; wherein the CDR1-H, CDR2-H, and CDR3-H comprised in the heavy chain variable region are identical to the CDR1-H, CDR2-H, and CDR3-H comprised in SEQ ID NO: 65. In one embodiment, the light chain variable region comprises CDR1-L as set forth in SEQ ID NO: 62, CDR2-L as set forth in SEQ ID NO: 63, and CDR3-L as set forth in SEQ ID NO: 64; and the heavy chain variable region comprises CDR1-H as set forth in SEQ ID NO: 59, CDR2-H as set forth in SEQ ID NO: 60, and CDR3-H as set forth in SEQ ID NO: 61.

[0035] In one embodiment, the antibody targeting FasL comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region is 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% identical to SEQ ID NO: 66, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 66; wherein the heavy chain variable region is 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% identical to SEQ ID NO: 65, or has a sequence identical to SEQ ID NO: 66. The anti-FasL antibody of the present invention comprises a heavy chain variable region as set forth in SEQ ID NO:65 and a light chain variable region as set forth in SEQ ID NO:66.

[0036] In one embodiment, the antibody targeting FasL is 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% identical to SEQ ID NO: 67, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 67. Preferably, the antibody targeting FasL is as shown in SEQ ID NO: 67.

[0037] In one embodiment, the immunosuppressive protein binding domain of the present invention comprises the extracellular region of a FasL ligand, such as the extracellular region of Fas. In one embodiment, the Fas extracellular region is 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% identical to SEQ ID NO: 68. In this embodiment, the immunosuppressive molecule may also comprise the corresponding transmembrane region of Fas, but generally does not also comprise its corresponding intracellular region. That is, the immunosuppressive molecule is not full-length Fas. In one embodiment, the Fas transmembrane region is 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% identical to SEQ ID NO: 69.

[0038] In one embodiment, the immunosuppressive protein binding domain of the present invention is an antibody targeting CTLA4. CTLA4, also known as CD152, is primarily expressed on the surface of activated T cells. It shares a high degree of homology with the T cell surface co-stimulatory molecule receptor CD28, but its affinity for the same ligands CD80 and CD86 is significantly higher than that of CD28. In contrast to the activating functions of CD28, which promote cytokine production, cell survival, and cell differentiation, CTLA4 transmits inhibitory signals to T cells.

[0039] Any anti-CTLA4 antibody known in the art can be used in the present invention. In one embodiment, the antibody targeting CTLA4 comprises a light chain variable region and a heavy chain variable region, wherein the CDR1-L, CDR2-L, and CDR3-L contained in the light chain variable region are identical to the CDR1-L, CDR2-L, and CDR3-L contained in SEQ ID NO: 77; wherein the CDR1-H, CDR2-H, and CDR3-H contained in the heavy chain variable region are identical to the CDR1-H, CDR2-H, and CDR3-H contained in SEQ ID NO: 76. In one embodiment, the light chain variable region comprises CDR1-L as shown in SEQ ID NO: 73, CDR2-L as shown in SEQ ID NO: 74, and CDR3-L as shown in SEQ ID NO: 75; and the heavy chain variable region comprises CDR1-H as shown in SEQ ID NO: 70, CDR2-H as shown in SEQ ID NO: 71, and CDR3-H as shown in SEQ ID NO: 72.

[0040] In one embodiment, the antibody targeting CTLA4 comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region is 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% identical to SEQ ID NO: 77, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 77; wherein the heavy chain variable region is 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% identical to SEQ ID NO: 76, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: The invention also provides an antibody comprising one or more (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 76. Preferably, the modifications are conservative modifications, such as conservative substitutions, additions, and deletions of amino acids. In a preferred embodiment, the anti-CTLA4 antibody of the invention comprises a heavy chain variable region as set forth in SEQ ID NO: 76 and a light chain variable region as set forth in SEQ ID NO: 77.

[0041] In one embodiment, the antibody targeting CTLA4 is 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% identical to SEQ ID NO: 78, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 78. Preferably, the antibody targeting CTLA4 is as shown in SEQ ID NO: 78.

[0042] In one embodiment, the immunosuppressive protein binding domain of the present invention comprises an extracellular region of a CTLA4 ligand, such as an extracellular region of CD80 or CD86. In one embodiment, the CD80 extracellular region is 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% identical to SEQ ID NO: 79; the CD86 extracellular region is 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% identical to SEQ ID NO: 80. In this embodiment, the immunosuppressive molecule may also comprise the corresponding transmembrane region of CD80 or CD86, but generally does not simultaneously comprise its corresponding intracellular region. That is, the immunosuppressive molecule is not full-length CD80 or CD86. In one embodiment, the CD80 transmembrane region is 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% identical to SEQ ID NO:81; and the CD86 transmembrane region is 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% identical to SEQ ID NO:82.

[0043] In one embodiment, the engineered cells express an exogenous immunosuppressive molecule, which comprises an anti-PD1 antibody, an anti-NKG2A antibody, an anti-FasL antibody, an anti-CTLA4 antibody, a Fas extracellular region, a CD80 extracellular region, a CD86 extracellular region, a PDL1 extracellular region, a PDL2 extracellular region, an HLA-E extracellular region, or a combination thereof, such as an anti-NKG2A antibody (or an HLA-E extracellular region) and an anti-PD1 antibody (or an PDL1 extracellular region, a PDL2 extracellular region), an anti-NKG2A antibody (or an HLA-E extracellular region) and an anti-FasL antibody (or an Fas extracellular region). ), anti-NKG2A antibody (or HLA-E extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region), anti-PD1 antibody (or PDL1 extracellular region, PDL2 extracellular region) and anti-FasL antibody (or Fas extracellular region), anti-PD1 antibody (or PDL1 extracellular region, PDL2 extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region), anti-FasL antibody (or Fas extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region) (the two binding domains in the combination can be connected by a linker).

[0044] In one embodiment, the engineered cells express two exogenous immunosuppressive molecules, each of which comprises a binding domain that binds to a different immunosuppressive protein. For example, the two exogenous immunosuppressive molecules bind to NKG2A and PD1, NKG2A and CTLA4, NKG2A and FasL, PD1 and CTLA4, PD1 and FasL, or CTLA4 and FasL, respectively. For example, in one embodiment, the engineered cells express two exogenous immunosuppressive molecules, which respectively include anti-NKG2A antibody (or HLA-E extracellular region) and anti-PD1 antibody (or PDL1 extracellular region, PDL2 extracellular region), anti-NKG2A antibody (or HLA-E extracellular region) and anti-FasL antibody (or Fas extracellular region), anti-NKG2A antibody (or HLA-E extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region), anti-PD1 antibody (or PDL1 extracellular region, PDL2 extracellular region) and anti-FasL antibody (or Fas extracellular region), anti-PD1 antibody (or PDL1 extracellular region, PDL2 extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region), anti-FasL antibody (or Fas extracellular region) and anti-CTLA4 antibody (or CD80 extracellular region, CD86 extracellular region). In this embodiment, the two exogenous immunosuppressive molecules can be linked via a 2A peptide (e.g., F2A, T2A, etc.). As used herein, "A (or B) and C (or D, E)" encompasses various combinations of A and C, A and D, A and E, B and C, B and D, and B and E.

[0045] As used herein, the term "conservative modification" refers to an amino acid modification that does not significantly affect or alter the binding characteristics of an antibody or antibody fragment containing the amino acid sequence. These conservative modifications include conservative substitutions, additions, and deletions of amino acids. Modifications can be introduced into the chimeric antigen receptors of the present invention by standard techniques known in the art, such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions are substitutions in which an amino acid residue is replaced by an amino acid residue with a similar side chain. Families of amino acid residues with similar side chains have been defined in the art and include basic side chains (e.g., lysine, arginine, histidine), acidic side chains (e.g., aspartic acid, glutamic acid), uncharged polar side chains (e.g., glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine), non-polar side chains (e.g., alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, tryptophan), β-branched side chains (e.g., threonine, valine, isoleucine), and aromatic side chains (e.g., tyrosine, phenylalanine, tryptophan, histidine). Conservative modifications may be selected, for example, on the basis of similarity in polarity, charge, solubility, hydrophobicity, hydrophilicity, and / or the amphipathic nature of the residues involved.

[0046] As used herein, the term sequence "identity" refers to the extent to which two (nucleotide or amino acid) sequences have the same residue at the same position in an alignment, and is usually expressed as a percentage. Preferably, identity is determined over the entire length of the sequences being compared. Thus, two copies of exactly the same sequence have 100% identity. It is known to those skilled in the art that sequence identity can be determined using algorithms such as Blast (Altschul et al. (1997) Nucleic Acids Res. 25: 3389-3402), Blast2 (Altschul et al. (1990) J. Mol. Biol. 215: 403-410), Smith-Waterman (Smith et al. (1981) J. Mol. Biol. 147: 195-197), and ClustalW.

[0047] As used herein, the term "transmembrane domain" refers to a polypeptide structure that enables expression of an immunosuppressive molecule on the cell surface and anchors the immunosuppressive protein-binding domain to the cell membrane. A transmembrane domain can be natural or synthetic and can be derived from any membrane-bound or transmembrane protein. When the target-binding domain binds to a target, the transmembrane domain enables signal transduction. Transmembrane domains particularly suitable for use in the present invention can be derived from, for example, TCRα chain, TCRβ chain, TCRγ chain, TCRδ chain, CD3ζ subunit, CD3ε subunit, CD3γ subunit, CD3δ subunit, CD28, CD45, CD4, CD5, CD8a, CD9, CD16, CD22, CD33, CD37, CD47, CD64, CD80, CD86, CD94, CD134, CD137, CD154, KIRDS2, OX40, CD2, CD27, CD18, ICOS, 4-1BB, GITR, CD40, BAFFR, HVEM, SLAMF7, NKp80, CD160, BCMA, IL-2Rβ, IL-2Rγ, IL-7R a, ITGA1, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CDl ld, ITGAE, CD103, ITGAL, CDl la, LFA-1, ITGAM, CDl lb, ITGAX, CDl lc, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, TNFR2, DNAM1, SLAMF4, CD84, CD96, CEACAM1, CRT AM, Ly9, CD160, PSGL1, CDIOO, SLAMF6, SLAMF1, SLAMF8, CD162, LTBR, ​​PAG / Cbp, NKp44, NKp30, NKp46, NKG2D or NKG2C. In some embodiments, the transmembrane domain is derived from the following molecules: CD8a, CD4, CD28, 4-1BB, CD47, CD80, CD86, CD152 and PD1. Alternatively, the transmembrane domain can be synthetic and can mainly contain hydrophobic residues such as leucine and valine. Preferably, the transmembrane domain is derived from CD28, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97% or 99% or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 14. Preferably, the transmembrane domain is derived from CD8a, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97% or 99% or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 15 or 16.

[0048] In one embodiment, the immunosuppressive molecule further comprises a hinge region between the immunosuppressive protein binding domain and the transmembrane domain. As used herein, the term "hinge region" generally refers to any oligopeptide or polypeptide that acts to connect the transmembrane domain to the antibody. Specifically, the hinge region is used to provide greater flexibility and accessibility for the antibody. The hinge region can comprise up to 300 amino acids, preferably 10 to 100 amino acids and most preferably 25 to 50 amino acids. The hinge region can be derived in whole or in part from natural molecules, such as whole or in part from the extracellular region of CD8, CD4 or CD28, or in whole or in part from an antibody constant region. Alternatively, the hinge region can be a synthetic sequence corresponding to a naturally occurring hinge sequence, or can be a fully synthetic hinge sequence. In a preferred embodiment, the hinge region comprises the hinge region portion of CD8α, CD28, FcγRIIIα receptor, IgG4 or IgG1, more preferably CD8α, CD28 or IgG4 hinge. In one embodiment, the hinge region is from CD28, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99% or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 26. In one embodiment, the hinge region is from CD8a, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99% or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 27 or 28. In one embodiment, the hinge region is from IgG4, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99% or 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 29.

[0049] As used herein, "costimulatory domain" refers to at least a portion of a protein that mediates intracellular signal transduction to induce an immune response such as an effector function, which is an intracellular functional signaling domain from a costimulatory molecule, comprising the entire intracellular region of the costimulatory molecule, or a functional fragment thereof. "Costimulatory molecule" refers to a cognate binding partner that specifically binds to a costimulatory ligand, thereby mediating a costimulatory response (e.g., proliferation and survival). The costimulatory signaling domain of any costimulatory molecule is suitable for use in immunosuppressive molecules as described herein. Costimulatory molecules include, but are not limited to, class 1 MHC molecules, BTLA, and Toll ligand receptors. The non-limiting examples of the costimulatory domains of the present invention include but are not limited to the intracellular region derived from following protein:LTB, CD94, TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, CARD11, CD2, CD7, CD8, CD18, CD27, CD28, CD30, CD40, CD54, CD83, CD134, 4-1BB, CD270, CD272, B7-H3, ICOS, CD357, DAP10, DAP12, LAT, NKG2C, SLP76, PD-1, LIGHT, TRIM, ZAP70 and their combination.Preferably, the costimulatory domains of CAR of the present invention are 4-1BB, CD28 or 4-1BB+CD28. In one embodiment, the costimulatory domain is from 4-1BB, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97% or 99% or 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 18 or 19. In one embodiment, the costimulatory domain is from CD28, which has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97% or 99% or 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 17.

[0050] The immunosuppressive molecules of the present invention do not include a primary signaling domain. As used herein, the term "primary signaling domain" refers to a protein structure that works together to trigger primary signaling after antigen-receptor binding, which is generally an intracellular sequence of a T cell receptor and a co-receptor. The primary signaling domain generally includes one or more immunoreceptor tyrosine-based activation motifs (ITAMs). Non-limiting examples of the primary signaling domain of the present invention include, but are not limited to, those derived from FcRγ, FcRβ, CD3γ, CD3δ, CD3ε, CD3ζ, CD5, CD22, CD79a, CD79b, NFAM1, STAM1, STAM2, and CD66d. In one embodiment, the immunosuppressive molecules of the present invention do not include a CD3ζ intracellular region. For example, the CD3ζ intracellular region has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99% or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 21, 22 or 20.

[0051] In one embodiment, the immunosuppressive molecule of the present invention further comprises a signal peptide so that when it is expressed in a cell, such as a T cell, the nascent protein is directed to the endoplasmic reticulum and subsequently to the cell surface. The core of the signal peptide may contain a long hydrophobic amino acid segment that has a tendency to form a single α-helix. At the end of the signal peptide, there is usually an amino acid segment that is recognized and cleaved by a signal peptidase. The signal peptidase can cleave during or after translocation to produce a free signal peptide and a mature protein. The free signal peptide is then digested by a specific protease. Signal peptides that can be used in the present invention are well known to those skilled in the art, such as signal peptides derived from B2M, CD8α, IgG1, GM-CSFRα, etc. In one embodiment, the signal peptide that can be used in the present invention is derived from B2M and has a sequence identity of at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99%, or 100% to the amino acid sequence shown in SEQ ID NO: 23. In one embodiment, the signal peptide useful in the present invention is derived from CD8a and has at least 70%, preferably at least 80%, more preferably at least 90%, 95%, 97%, 99% or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 24 or 25.

[0052] Functional xenobiotic receptors

[0053] In one embodiment, the engineered cells of the present invention may further express a functional exogenous receptor. Preferably, the functional exogenous receptor is selected from a recombinant T cell receptor, a chimeric antigen receptor, a T cell fusion protein, or a T cell antigen coupler, more preferably a chimeric antigen receptor.

[0054] As used herein, the term "T cell fusion protein" or "TFP" refers to a recombinant polypeptide derived from various components of a TCR, typically consisting of a TCR subunit and an antibody linked thereto, and expressed on the cell surface. The TCR subunit includes at least a portion of the TCR extracellular domain, the transmembrane domain, and the TCR intracellular signaling domain.

[0055] As used herein, the term "T cell antigen coupler" or "TAC" includes three functional domains: 1. a tumor targeting domain, including a single-chain antibody, a designed ankyrin repeat protein (DARPin), or other targeting groups; 2. an extracellular domain, a single-chain antibody that binds to CD3, thereby bringing the TAC receptor into proximity with the TCR receptor; 3. a transmembrane region and an intracellular region of the CD4 co-receptor, wherein the intracellular region is connected to the protein kinase LCK, which catalyzes the phosphorylation of the immunoreceptor tyrosine-based activation motif (ITAM) of the TCR complex as the initial step in T cell activation.

[0056] As used herein, the term "T cell receptor" or "TCR" is a characteristic marker on the surface of T cells, which binds to CD3 with a non-covalent bond to form a complex. Antigen presenting cells present antigen peptides to T cells through major histocompatibility complex molecules (MHC) and bind to the TCR complex to induce a series of intracellular signal transductions. TCR consists of six peptide chains that form heterodimers, which are generally divided into αβ type and γδ type. Each peptide chain includes a constant region and a variable region, wherein the variable region is responsible for binding to specific antigens and MHC molecules. The term "recombinant TCR receptor" refers to an artificially constructed T cell receptor that further comprises an antigen (e.g., tumor antigen) binding domain.

[0057] As used herein, the term "chimeric antigen receptor" or "CAR" refers to an artificially constructed hybrid polypeptide that generally includes an antigen (e.g., tumor antigen) binding domain (e.g., a ligand for an antibody or antigen), a transmembrane domain, an optional costimulatory domain, and a primary signaling domain, with each domain connected by a joint. CAR is capable of redirecting the specificity and reactivity of T cells and other immune cells to a selected target in a non-MHC restricted manner. In one embodiment, the functional exogenous receptor of the present invention is a chimeric antigen receptor comprising a tumor antigen binding domain, a transmembrane domain, one or more costimulatory domains, and a primary signaling domain. In one embodiment, the chimeric antigen receptor further comprises one or more of the following structures: a signal peptide, a hinge region, a suicide gene, a switch structure, and the like.

[0058] In one embodiment, the functional exogenous receptor comprises an extracellular domain that specifically recognizes an antigen (e.g., a tumor antigen). In one embodiment, the extracellular domain comprises an antibody that specifically binds to an antigen or a ligand for the antigen. In one embodiment, the antigen is selected from the group consisting of ALK, ADRB3, AKAP-4, APRIL, ASGPR1, BCMA, B7H3, B7H4, B7H6, bcr-abl, BORIS, BST2, BAFF-R, BTLA, CD2, CD3, CD4, CD5, CD7, CD8, CD19, CD20, CD22, CD24, CD25, CD28, CD30, CD33, CD38, CD40, CD44, CD44v6, CD44v7 / 8, CD47, CD52, CD56, CD57, CD58, CD70, CD72, CD79a, CD79b, CD80, CD81, CD86, CD97, CD123, CD133, CD137, CD 138, CD151, CD171, CD179a, CD300LF, CLEC12A, CDH16, CSPG4, CS1, CLL-1, Claudin6, Claudin18.1, Claudin 18.2, CEA, CEACAM6, c-Met, CAIX, CXORF61, CA125, CYP1B1, CS1, ELF2M, EGFR, EPCAM, EGFRvIII, EphA2, ERG / TMPRSS2ETS fusion gene, ETV6-AML, EMR2, EGP2,EGP40, FAP, FAR, FBP, FLT3, FOSL1, FCRL5, FCAR, Flt3, Flt4, Frizzled, GD2, GD3, gp100, gp130, GM3, GPC2, GPC3, GPRC5D, GPR20, GloboH, GHRHR, GHR, GITR, Her2, HER3, HER-4, HMWMAA, HAVCR1, HPV E6,E7, HVEM, HIV-1Gag, HLA-A1, HLA-A2, IL6R, IL-11Ra, IL-13Ra, IGF-I receptor, LTPR, LIFRP, LRP5, IGLL1, IGF1R, KIT, Kappa Light Chain, KDR, LewisY, LMP2, LY6K, LAGE-1a, legumain, LCK, LAIR1, LILRA2, LY75, MSLN, MUC1, MUC16, MAGE-A1, MAGE3, MAD-CT-1, MelanA / MART1, ML-IAP, MYCN, mut hsp70-2, NCAM, NY-BR-1, NY-ESO-1, NA17, Notch-1-4, nAchR, NKG2D, NKG2D ligand, OY-TES1, OR51E2, OX40, PRSS21, PSCA, PD1, PD-L1, PD-L2, PSMA, Prostase, PAP, PDGFR-β, PCTA-1 / galectin 8, p53, p53 mutant, prostein, PLAC1, PANX3, PAX3, PAX5, PTCH1, RANK, RAGE-1, ROR1, Ras mutant, RhoC, RU1, RU2, Robol, SSEA-4, SSX2, SART3, Sp17, TSHR, Tn Ag, TGS5, TEM1 / CD248, TEM7R, TARP, TCRα, TCRβ, TGFBR1, TGFBR2, TNFRSF4, TWEAK-R, TLR7, TLR9, TAG72, TROP-2, Tie 2, TRP-2, TNFR1, TNFR2, TEM1, UPK2 VEGFR, WT1, XAGE1, 5T4, 8H9, αvβ6 integrin, CA9, folate receptor α, ephrin B2, tyrosinase, fucosyl GM1, o-acetyl-GD2, folate receptor β, polysialic acid, sperm protein 17, survivin and telomerase, sarcoma translocation breakpoints, human telomerase / hTERT, androgen receptor, intestinal carboxylesterase, cyclin B1, fibronectin, tenascin, oncofetal variants of tumor necrosis, or any combination thereof. Preferably,The antigen is selected from CD7, CD19, CD20, CD22, CD30, CD33, CD38, CD123, CD138, CD171, MUC1, MSLN, AFP, folate receptor α, CEA, PSCA, PSMA, Her2, EGFR, IL-13Ra, GD2, NKG2D, Claudin18.2, ROR1, EGFRvIII, CS1, BCMA and GPRC5D, more preferably selected from ROR1, CD19, Claudin18.2, MSLN, GPRC5D, CD7 and BCMA.

[0059] In one embodiment, the functional exogenous receptor comprises an extracellular domain that specifically recognizes CD19, such as an antibody targeting CD19. In one embodiment, the antibody targeting CD19 comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region comprises CDR1-L as shown in SEQ ID NO: 8, CDR2-L as shown in SEQ ID NO: 9, and CDR3-L as shown in SEQ ID NO: 10; and the heavy chain variable region comprises CDR1-H as shown in SEQ ID NO: 5, CDR2-H as shown in SEQ ID NO: 6, and CDR3-H as shown in SEQ ID NO: 7.

[0060] In one embodiment, the antibody targeting CD19 comprises a light chain variable region and a heavy chain variable region, wherein the light chain variable region is 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% identical to SEQ ID NO: 12, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 12; wherein the heavy chain variable region is 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% identical to SEQ ID NO: 11, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: The antibody of the present invention comprises a heavy chain variable region as set forth in SEQ ID NO: 11 and a light chain variable region as set forth in SEQ ID NO: 12.

[0061] In one embodiment, the antibody targeting CD19 is 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% identical to SEQ ID NO: 13, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 13. Preferably, the antibody targeting CD19 is as shown in SEQ ID NO: 13.

[0062] In one embodiment, the functional exogenous receptor comprises an extracellular domain that specifically recognizes Claudin18.2, such as an antibody targeting Claudin18.2. In one embodiment, the antibody targeting Claudin18.2 is a single-domain antibody. Preferably, the single-domain antibody comprises CDR1 as set forth in SEQ ID NO: 1, CDR2 as set forth in SEQ ID NO: 2, and CDR3 as set forth in SEQ ID NO: 3.

[0063] In one embodiment, the antibody targeting Claudin18.2 has 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% identity to SEQ ID NO: 4, or has one or several (e.g., at most 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids) amino acid modifications compared to the amino acid sequence of SEQ ID NO: 4. Preferably, the antibody targeting Claudin18.2 is as shown in SEQ ID NO: 4.

[0064] In one embodiment, the functional exogenous receptor of the present invention is a chimeric antigen receptor comprising an antigen binding domain, a transmembrane domain, one or more costimulatory domains, and a primary signaling domain. In one embodiment, the functional exogenous receptor of the present invention is a chimeric antigen receptor that targets CD19, CD7, CD19, CD20, CD22, CD30, CD33, CD38, CD123, CD138, CD171, MUC1, MSLN, AFP, folate receptor α, CEA, PSCA, PSMA, Her2, EGFR, IL-13Ra, GD2, NKG2D, Claudin18.2, ROR1, EGFRvIII, CS1, BCMA, or GPRC5D, more preferably targeting CD19, Claudin18.2, MSLN, ROR1, GPRC5D, CD7, and BCMA. In one embodiment, the chimeric antigen receptor further comprises a signal peptide, a hinge region, or both. The definitions of the transmembrane domain, co-stimulatory domain, primary signaling domain, and optional hinge region, signal peptide, etc. of the CAR that can be used in the present invention are described in the "Immunosuppressive Molecules" section above.

[0065] In one embodiment, the CAR of the present invention may further comprise a switch structure to regulate the expression time of CAR. For example, the switch structure may be in the form of a dimerization domain, which causes a conformational change by binding to its corresponding ligand, exposing the extracellular binding domain, so that it binds to the targeted antigen, thereby activating the signal transduction pathway. Alternatively, the switch domain may be used to connect the binding domain and the signal transduction domain respectively, and only when the switch domains bind to each other (for example, in the presence of an inducing compound) can the binding domain and the signal transduction domain be connected together through a dimer, thereby activating the signal pathway. The switch structure may also be in the form of a masking peptide. The masking peptide may shield the extracellular binding domain, preventing it from binding to the targeted antigen, and when the masking peptide is cleaved by, for example, a protease, the extracellular binding domain may be exposed, making it a "normal" CAR structure. Various switch structures known to those skilled in the art may be used in the present invention.

[0066] In one embodiment, the CAR of the present invention may also include a suicide gene, that is, it is expressed by a cell death signal that can be induced by an exogenous substance, so as to remove the CAR cells when needed (for example, when serious toxic side effects are produced). For example, the suicide gene can be in the form of an inserted epitope, such as a CD20 epitope, RQR8, etc., and when needed, the CAR cells can be eliminated by adding antibodies or reagents targeting these epitopes. The suicide gene can also be herpes simplex virus thymidine kinase (HSV-TK), which can cause cells to die under the induction of ganciclovir treatment. The suicide gene can also be iCaspase-9, which can be induced by chemical induction drugs such as AP1903, AP20187, etc. to dimerize iCaspase-9, thereby activating downstream Caspase3 molecules, leading to apoptosis. Various suicide genes known to those skilled in the art can be used in the present invention.

[0067] Engineered cells

[0068] In one embodiment, the engineered cells of the invention are engineered immune cells.

[0069] As used herein, the term "immune cell" refers to any cell with one or more effector functions (e.g., cytotoxic cell killing activity, secretion of cytokines, induction of ADCC and / or CDC) of the immune system. For example, immune cell can be a B cell, a T cell, a macrophage, a dendritic cell, a monocyte, a NK cell or a NKT cell. Immune cell can be obtained from a variety of sources, for example, from a subject (e.g., from subject's peripheral blood mononuclear cells, bone marrow, lymph node tissue, cord blood, thymus tissue, tissue from infection site, ascites, pleural effusion, spleen tissue, tumor etc.), or from a cell line (e.g., Jurkat, SupT1, NK92 etc.) cultured in vitro, or from stem cell differentiation (e.g., derived from cord blood stem cells, progenitor cells, bone marrow stem cells, hematopoietic stem cells, adult stem cells, embryonic stem cells, pluripotent stem cells, iPSC etc.). Preferably, immune cell is a T cell or a NK cell, more preferably a T cell. T cell can also be concentrated or purified. T cells can be in any developmental stage, including but not limited to, CD4+CD8+T cells, CD4+T cells (e.g., Th1 and Th2 cells), CD8+T cells (e.g., cytotoxic T cells), CD4-CD8-T cells, tumor infiltrating cells, memory T cells, immature T cells, γδ-T cells, αβ-T cells, etc. In a preferred embodiment, the immune cells are human T cells. T cells can be obtained from the blood of a subject using a variety of techniques known to those skilled in the art, such as Ficoll separation.

[0070] In one embodiment, the engineered cells of the present invention are engineered stem cells or are differentiated from such stem cells. Examples of stem cells include, but are not limited to, cord blood stem cells, progenitor cells, bone marrow stem cells, hematopoietic stem cells, adult stem cells, embryonic stem cells, pluripotent stem cells, iPS cells, and the like.

[0071] In one embodiment, the endogenous HLA class I and / or HLA class II genes of the engineered cells of the present invention are unmodified. In one embodiment, the endogenous HLA class I genes of the engineered cells of the present invention are unmodified. In one embodiment, the endogenous HLA class II genes of the engineered cells of the present invention are unmodified. In one embodiment, the endogenous HLA class I and HLA class II genes of the engineered cells of the present invention are unmodified. In one embodiment, the expression of at least one endogenous HLA class I gene and / or at least one HLA class II gene of the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous HLA class I gene of the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous HLA class II gene of the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous HLA class I gene and at least one endogenous HLA class II gene of the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous TCR / CD3 gene of the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous TCR / CD3 gene and at least one endogenous HLA-I class gene in the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous TCR / CD3 gene and at least one endogenous HLA-II class gene in the engineered cells of the present invention is downregulated. In one embodiment, the expression of at least one endogenous TCR / CD3 gene, at least one endogenous HLA-I class gene, and at least one endogenous HLA-II class gene in the engineered cells of the present invention is downregulated. Preferably, the HLA-I class gene is selected from HLA-A, HLA-B, HLA-C, and B2M. Preferably, the HLA-II class gene is selected from HLA-DP, HLA-DQ, HLA-DR, TAP1, TAP2, LMP2, LMP7, RFX5, RFXAP, RFXANK, and CIITA, preferably selected from RFX5, RFXAP, RFXANK, and CIITA. Preferably, the TCR / CD3 gene is selected from TRAC, TRBC, CD3γ, CD3δ, CD3ε and CD3ζ.

[0072] In one embodiment, the engineered cells of the present invention are allogeneic cells. As used herein, the term "allogeneic" refers to any material derived from a different animal or patient of the same species as the individual into which the material is introduced. Two or more individuals are considered allogeneic to each other when the genes at one or more loci are different. In some cases, allogeneic material from individuals of the same species may differ genetically enough to cause antigenic interaction.

[0073] Pharmaceutical composition

[0074] The present invention also provides a pharmaceutical composition comprising the engineered cells of the present invention as an active agent and one or more pharmaceutically acceptable excipients. Therefore, the present invention also encompasses the use of the engineered cells in the preparation of a pharmaceutical composition or a medicament.

[0075] As used herein, the term "pharmaceutically acceptable excipient" refers to a carrier and / or excipient that is pharmacologically and / or physiologically compatible with the subject and the active ingredient (i.e., capable of inducing the desired therapeutic effect without causing any undesirable local or systemic effects), which is well known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19th ed. Pennsylvania: Mack Publishing Company, 1995). Examples of pharmaceutically acceptable excipients include, but are not limited to, fillers, binders, disintegrants, coatings, adsorbents, antiadherents, glidants, antioxidants, flavorings, colorants, sweeteners, solvents, cosolvents, buffers, chelating agents, surfactants, diluents, wetting agents, preservatives, emulsifiers, coatings, isotonic agents, absorption delaying agents, stabilizers, and tension modifiers. It is known to those skilled in the art to select suitable excipients to prepare the pharmaceutical compositions desired in the present invention. Exemplary excipients for use in the pharmaceutical compositions of the present invention include saline, buffered saline, glucose, and water. In general, the choice of suitable excipients depends on, inter alia, the active agent used, the disease to be treated and the desired dosage form of the pharmaceutical composition.

[0076] The pharmaceutical composition according to the present invention can be applied in a variety of ways. Typically, administration is accomplished parenterally. Parenteral delivery methods include topical, intra-arterial, intramuscular, subcutaneous, intramedullary, intrathecal, intraventricular, intravenous, intraperitoneal, intrauterine, intravaginal, sublingual, or intranasal administration.

[0077] The pharmaceutical composition according to the present invention can also be prepared in various forms, such as solid, liquid, gaseous or lyophilized forms, particularly in the form of ointments, creams, transdermal patches, gels, powders, tablets, solutions, aerosols, granules, pills, suspensions, emulsions, capsules, syrups, elixirs, extracts, tinctures or fluid extracts, or in a form particularly suitable for the desired method of administration. The processes known in the present invention for producing drugs may include, for example, conventional mixing, dissolving, granulating, sugar coating, grinding, emulsifying, encapsulating, embedding or lyophilizing processes. Pharmaceutical compositions comprising, for example, immune cells as described herein are typically provided in solution form and preferably comprise a pharmaceutically acceptable buffer.

[0078] The pharmaceutical composition according to the present invention can also be used in combination with one or more other medicaments (biological agents such as antibody reagents, and / or small molecules) or therapeutic methods (such as surgery, chemotherapy or radiotherapy) that are applicable to the treatment and / or prevention of the disease to be treated. Preferred examples of the medicament suitable for combination include known anticancer drugs, such as cisplatin, maytansine derivatives, rachelmycin (rachelmycin), calicheamicin (calicheamicin), docetaxel, etoposide, gemcitabine, ifosfamide, irinotecan, melphalan, mitoxantrone, sorfimer sodium porphyrin II (sorfimer sodium photofrin II), temozolomide, topotecan, trimetreate glucuronate (trimetreate glucuronate), auristatin E (auristatin E), vincristine and doxorubicin; peptide cytotoxins such as ricin, diphtheria toxin, Pseudomonas exotoxin A, DNA enzymes and RNA enzymes; radionuclides such as iodine-131, rhenium-186, indium-111, iridium-90, bismuth-210 and 213, actinium-225 and astatine-213; prodrugs such as antibody-directed enzyme prodrugs; immunostimulants such as platelet factor 4 and melanoma growth stimulating protein; antibodies or fragments thereof such as anti-CD3 antibodies or fragments thereof, complement activators, heterologous protein domains, homologous protein domains, viral / bacterial protein domains and viral / bacterial peptides. In addition, the pharmaceutical compositions of the present invention can also be used in combination with one or more other treatment methods, such as chemotherapy and radiotherapy.

[0079] In one embodiment, the pharmaceutical compositions of the present invention are used to treat a subject suffering from cancer, infection, or autoimmune disease.

[0080] In one embodiment, the cancer is a cancer associated with expression of a target to which a functional exogenous receptor binds. For example, the cancer includes, but is not limited to, brain gliomas, blastomas, sarcomas, leukemias, basal cell carcinomas, biliary tract cancer, bladder cancer, bone cancer, brain and CNS cancers, breast cancer, peritoneal cancer, cervical cancer, choriocarcinoma, colon and rectal cancer, connective tissue cancer, cancers of the digestive system, endometrial cancer, esophageal cancer, eye cancer, head and neck cancer, gastric cancer (including gastrointestinal cancer), glioblastoma (GBM), liver cancer, hepatoma, intraepithelial neoplasia, kidney cancer, laryngeal cancer, liver tumors, lung cancers (e.g., small cell lung cancer, non-small cell lung cancer, adenocarcinoma and squamous lung cancer), lymphoma (including Hodgkin lymphoma and non-Hodgkin lymphoma), melanoma, myeloma, neuroblastoma, oral cancer (e.g., lip, tongue, mouth, and pharynx), ovarian cancer, pancreatic cancer, prostate cancer, retinoblastoma, rhabdomyosarcoma, rectal cancer, cancers of the respiratory system, salivary gland cancer, skin cancer, squamous cell carcinoma, stomach cancer, testicular cancer, thyroid cancer, uterine or endometrial cancer, malignancies of the urinary system, vulvar cancer, and other carcinomas and sarcomas, and B-cell lymphomas (including low-grade / follicular non-Hodgkin lymphoma (NHL) ), small lymphocytic (SL) NHL, intermediate-grade / follicular NHL, intermediate-grade diffuse NHL, high-grade immunoblastic NHL, high-grade lymphoblastic NHL, high-grade small non-cleaved cell NHL, large mass disease NHL), mantle cell lymphoma, AIDS-related lymphoma, and Waldenstrom macroglobulinemia, chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), B-cell acute lymphoblastic leukemia (B-ALL), T-cell acute lymphoblastic leukemia (T-ALL), B-cell prolymphocytic leukemia, blastic plasmacytoid dendritic cell neoplasm, Burkitt's lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, chronic myeloid leukemia (CML), malignant lymphoproliferative disease, MALT lymphoma, hairy cell leukemia, marginal zone lymphoma, multiple myeloma, myelodysplasia, plasmablastic lymphoma, preleukemia, plasmacytoid dendritic cell neoplasm, and post-transplantation lymphoproliferative disorder (PTLD); and other diseases related to target expression. Preferably, the diseases that can be treated with the engineered immune cells or pharmaceutical compositions of the present invention are selected from: leukemia, lymphoma, multiple myeloma, brain glioma, pancreatic cancer, gastric cancer, etc.

[0081] In one embodiment, the infection includes, but is not limited to, infections caused by viruses, bacteria, fungi, and parasites.

[0082] In one embodiment, the autoimmune diseases include but are not limited to type I diabetes, celiac disease, Graves' disease, inflammatory bowel disease, multiple sclerosis, psoriasis, rheumatoid arthritis, Addison's disease, Sjögren's syndrome, Hashimoto's thyroiditis, myasthenia gravis, vasculitis, pernicious anemia and systemic lupus erythematosus.

[0083] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with examples. It should be noted that those skilled in the art should understand that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and do not constitute any limitation to the present invention. The embodiments and features in the embodiments of the present application may be combined with each other unless there is any contradiction. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] FIG1 shows the cytotoxic activity of Fas-knockout CAR-T cells against target cells.

[0085] Figure 2 shows the cytokine release levels after Fas knockout CAR-T cells (A: CAR-T cells targeting CD19; B: CAR-T cells targeting Claudin18.2) were co-incubated with target cells.

[0086] FIG3 shows the inhibitory effect of Fas-knockout CAR-T cells (A: CAR-T cells targeting CD19; B: CAR-T cells targeting Claudin18.2) on T cell killing.

[0087] FIG4 shows the in vivo tumor suppression effect of Fas knockout CAR-T cells.

[0088] FIG5 shows the killing activity of CAR-T cells against target cells in which TGFBR1 or TGFBR2 was knocked out (A: CAR-T cells comprising immunosuppressive molecules targeting NKG2A and PD1; B: CAR-T cells comprising immunosuppressive molecules targeting FasL).

[0089] Figure 6: Shows the cytokine release levels after TGFBR1 or TGFBR2 knockout CAR-T cells are co-incubated with target cells (A: IL2 and IFN-γ release levels of CAR-T cells containing immunosuppressive molecules targeting NKG2A and PD1; B: IL2 release levels of CAR-T cells containing immunosuppressive molecules targeting FasL; C: IFN-γ release levels of CAR-T cells containing immunosuppressive molecules targeting FasL).

[0090] FIG7 shows the in vivo tumor suppression effect of CAR-T cells with TGFBR1 or TGFBR2 knockout (A: CAR-T cells containing immunosuppressive molecules targeting NKG2A and PD1; B: CAR-T cells containing immunosuppressive molecules targeting FasL). DETAILED DESCRIPTION

[0091] Structures of exemplary CARs and immunosuppressive molecules used in the following examples:

[0092] The CAR structure comprises an extracellular domain, a CD8α hinge region (SEQ ID NO: 27), a CD8α transmembrane region (SEQ ID NO: 15), a 4-1BB costimulatory domain (SEQ ID NO: 18), and a CD3ζ intracellular region (SEQ ID NO: 21) connected in sequence. The extracellular domain included in the CD19 CAR structure is an anti-CD19 scFv (SEQ ID NO: 13). The extracellular domain included in the Claudin18.2 CAR structure is an anti-Claudin18.2 vhh (SEQ ID NO: 4).

[0093] The structure of the PD1-targeting immunosuppressive molecule IIM-PDL1 comprises a PDL1 signal peptide (SEQ ID NO: 53), a PDL1 extracellular region (SEQ ID NO: 55), a PDL1 transmembrane region (SEQ ID NO: 54), and a CD28 costimulatory domain (SEQ ID NO: 17) connected in sequence.

[0094] The structure of the NKG2A-targeting immunosuppressive molecule IIM-NKG2A comprises an anti-NKG2A scFv (SEQ ID NO: 41), an IgG4 hinge region (SEQ ID NO: 29), a CD28 transmembrane region (SEQ ID NO: 14), and a CD28 costimulatory domain (SEQ ID NO: 17) connected in sequence.

[0095] The structure of the FasL-targeting immunosuppressive molecule IIM-FasL comprises a B2M signal peptide (SEQ ID NO: 23), an anti-FasL scFv (SEQ ID NO: 67), an IgG4 hinge region (SEQ ID NO: 29), a CD28 transmembrane region (SEQ ID NO: 14), and a CD28 costimulatory domain (SEQ ID NO: 17), which are connected in sequence.

[0096] Example 1. Construction of CAR-T immune cells of the present invention

[0097] The coding sequence of CD19 CAR was synthesized and cloned into the pGEM-T Easy vector (Promega) to obtain the CAR19 plasmid. The CAR19 plasmid further contained the coding sequence of the immunosuppressive molecule IIM-PDL1 targeting PD1 linked by T2A (SEQ ID NO: 30) to obtain the CAR19P plasmid.

[0098] The coding sequence of Claudin18.2 CAR was synthesized and cloned into the pGEM-T Easy vector (Promega) to obtain the CAR18.2 plasmid. The CAR18.2 plasmid further contained the coding sequence of the immunosuppressive molecule IIM-PDL1 targeting PD1 and the coding sequence of the immunosuppressive molecule IIM-NKG2A targeting NKG2A, respectively, linked by T2A (SEQ ID NO: 30), to obtain the CAR18.2AP plasmid. The CAR18.2 plasmid further contained the coding sequence of the immunosuppressive molecule IIM-FasL targeting FasL, respectively, linked by T2A (SEQ ID NO: 30), to obtain the CAR18.2FL plasmid.

[0099] After diluting the plasmid in 3 ml of Opti-MEM (Gibco) in a sterile tube, the packaging vector psPAX2 (Addgene) and the envelope vector pMD2.G (Addgene) were added at a ratio of 4:2:1 between plasmid:viral packaging vector:viral envelope vector. Next, 120 μl of X-treme GENE HP DNA transfection reagent (Roche) was added, mixed immediately, and incubated at room temperature for 15 minutes. The plasmid / vector / transfection reagent mixture was then added dropwise to the 293T cell culture flask. Viruses were collected at 24 and 48 hours, pooled, and concentrated by ultracentrifugation (25,000 g, 4°C, 2.5 hours).

[0100] T cells were activated with DynaBeads CD3 / CD28 CTSTM (Gibco) and cultured for 1 day at 37°C and 5% CO2. The next day, concentrated lentivirus was added and cultured for 3 days to obtain T cells (CAR19) expressing CD19 CAR, T cells (CAR19P) expressing CD19 CAR and IIM-PDL1 combination, T cells (CAR18.2FL) expressing Claudin18.2 CAR and IIM-FasL, and T cells (CAR18.2AP) expressing Claudin18.2 CAR and two immunosuppressive molecules (IIM-PDL1+IIM-NKG2A) combination. In addition, T cells (CAR19, CAR19P and CAR18.2AP) in which the Fas gene was knocked out using the CRISPR / Cas9 system were transfected with the above-mentioned lentivirus to obtain CAR19-Fas KO T cells, CAR19P-Fas KO T cells and CAR18.2AP-Fas KO T cells.

[0101] Example 2. Killing effect of CAR-T cells on target cells

[0102] 1×10 4 Target Raji cells were plated into 96-well plates at a concentration of 10 cells / well. NT cells, CAR19P T cells, CAR19-Fas KO T cells, and CAR19P-Fas KO T cells were then plated into 96-well plates at an effector-target ratio of 4:1, 2:1, 1:1, or 0.5:1 for co-culture. After 18 hours, fluorescence values ​​were measured using a microplate reader. The killing efficiency was calculated according to the formula: (target cell fluorescence mean - sample fluorescence mean) / target cell fluorescence mean × 100%, and the results are shown in Figure 1.

[0103] It can be seen that CAR19P T cells, CAR19-Fas KO T cells, and CAR19P-Fas KO T cells all showed effective and specific killing of target cells, and the killing activity of CAR19P-Fas KO T cells was significantly improved compared with the first two. This indicates that the combination of downregulating the Fas gene and expressing immunosuppressive molecules produces a synergistic effect, which can maximize the killing effect of CAR19T cells.

[0104] Example 3. Cytokine release levels after co-incubation of CAR-T cells with target cells

[0105] 1×10 5Target cells (Raji cells) were plated in a 96-well plate at a concentration of 1 cell / well, and NT cells, CAR19P T cells, and CAR19P-Fas KO T cells were added at a ratio of 1:1. After 18-24 hours of co-culture, the cell co-culture supernatant was collected. The contents of IL2 and IFN-γ in the co-culture supernatant were detected using Human IL-2 DuoSet ELISA Kit (R&D systems) and Human IFN-gamma DuoSet ELISA Kit (R&D systems), respectively. The results are shown in Figure 2A. It can be seen that compared with NT cells, the release levels of cytokines IL2 and IFN-γ were significantly increased after co-culture of the two CAR-T cells with target cells, indicating that this cytokine release is specific. In addition, knocking out the Fas gene significantly increased the level of IFNγ release by CAR19 T cells.

[0106] The same method was used to detect the cytokine release level after co-incubation of Claudin18.2-targeting CAR-T cells with target cells NUGC4-18.2, and the results are shown in Figure 2B. Similarly, knocking out the Fas gene significantly increased the IFNγ release level of CAR18.2T cells.

[0107] Example 4. Knockout of the Fas gene significantly enhances CAR-T cell survival

[0108] In order to verify the ability of CAR-T cells in which Fas gene expression was downregulated to resist killing, 1×10 5 The CAR-T cells of the present invention were plated into a 96-well plate at a concentration of 1 cell / well, and then the effector cell CAR7T cells (T cells expressing CD7 CAR, labeled with Far-red) were also plated into the 96-well plate for co-culture at a 1:1 effector-target ratio. After 24 hours, the survival rate of the CAR-T cells of the present invention was detected by flow cytometry. The results are shown in Figure 3A (targeting CD19) and Figure 3B (targeting Claudin18.2).

[0109] It can be seen that the survival rate of CAR19P-T cells and CAR18.2AP-T cells that only express immunosuppressive molecules is comparable to that of NT cells, and further knockout of the Fas gene can significantly improve the survival of CAR-T cells.

[0110] Example 5. In vivo inhibitory effect of CAR T cells on tumors

[0111] Fifteen healthy female NPI mice aged 6-8 weeks were divided into three groups, with 5 mice in each group: NT cells, CAR19P-T cells, and CAR19P-Fas KO T cells. On day 0, 5×105 After 6 days, 2x10 Raji cells were injected into the tail vein of each mouse according to the grouping situation. 6 The mice were then assessed weekly. The survival curves are shown in Figure 4.

[0112] It can be seen that the survival rate of mice treated with CAR19P-T cells was significantly higher than that of the control group, and the CAR19P-Fas KO T cell group with Fas gene knockout showed the longest survival period. This indicates that knocking out the endogenous Fas gene can enhance the in vivo killing activity of CAR-T cells.

[0113] Example 6. Construction of CAR-T cells with TGFBR1 or TGFBR2 knockout and expression of immunosuppressive molecules and verification of their function

[0114] CAR-T cells in which TGFBR1 or TGFBR2 was knocked out and immunosuppressive molecules were expressed were constructed according to the method of Example 1. Specifically, the CAR18.2AP and CAR18.2FL plasmids prepared in Example 1 were respectively packaged into lentivirus, and then transfected into T cells in which TGFBR1 was knocked out using the CRISPR / Cas9 system to obtain CAR18.2AP-TR1 KO T cells and CAR18.2FL-TR1 KO T cells; or transfected into T cells in which TGFBR2 was knocked out using the CRISPR / Cas9 system to obtain CAR18.2AP-TR2 KO T cells and CAR18.2FL-TR2 KO T cells.

[0115] The killing activity of the above-mentioned CAR-T cells was detected using the method described in Example 2, and the results are shown in Figure 5A (CAR-T cells containing immunosuppressive molecules targeting NKG2A and PD1) and Figure 5B (CAR-T cells containing immunosuppressive molecules targeting FasL). It can be seen that compared with CAR18.2AP T cells, additional knockout of TGFBR1 or TGFBR2 genes did not significantly affect the killing activity of CAR-T cells; compared with CAR18.2FL T cells, additional knockout of TGFBR1 or TGFBR2 genes enhanced the killing activity of CAR-T cells.

[0116] The cytokine release levels after the above-mentioned CAR-T cells were co-incubated with target cells were detected using the method described in Example 3. The results are shown in Figure 6A (IL2 and IFN-γ release levels of CAR-T cells containing immunosuppressive molecules targeting NKG2A and PD1), Figure 6B (IL2 release levels of CAR-T cells containing immunosuppressive molecules targeting FasL), and Figure 6C (IFN-γ release levels of CAR-T cells containing immunosuppressive molecules targeting FasL). It can be seen that compared with CAR18.2AP T cells or CAR18.2FL T cells, additional knockout of TGFBR1 or TGFBR2 genes did not significantly affect the release level of cytokines.

[0117] Twenty healthy female NPI mice aged 6-8 weeks were divided into four groups, with 5 mice in each group: NT cells, CAR18.2AP T cells, CAR18.2AP-TR1 KO T cells, and CAR18.2AP-TR2 KO T cells. Another 20 healthy female NPI mice aged 6-8 weeks were divided into four groups, with 5 mice in each group: NT cells, CAR18.2FL T cells, CAR18.2FL-TR1 KO T cells, and CAR18.2FL-TR2 KO T cells. On day 0, 4×10 6 NUGC4-18.2 cells. After 14 days, 2x10 6 NT cells or corresponding CAR-T cells. The status of the mice was assessed weekly. The progression of mouse tumor burden is shown in Figure 7A (CAR-T cells containing immunosuppressive molecules targeting NKG2A and PD1) and Figure 7B (CAR-T cells containing immunosuppressive molecules targeting FasL). It can be seen that compared with CAR18.2AP T cells, additional knockout of TGFBR1 or TGFBR2 genes significantly reduced the tumor burden of mice and maintained it at a low level until the end of the experiment, when almost no tumor cells were detected; compared with CAR18.2FL T cells, additional knockout of TGFBR1 or TGFBR2 genes significantly reduced the tumor burden of mice, and the effect of CAR-T cells in reducing tumor burden was more significant after knockout of the TGFBR2 gene.

[0118] In summary, knocking out endogenous genes such as Fas, TGFBR1, and TGFBR2 and expressing immunosuppressive molecules will not adversely affect the killing activity or cytokine release characteristics of CAR-T cells (even when Fas is knocked out and immunosuppressive molecules are expressed, a synergistic effect can be produced, significantly improving their killing activity and IFNγ release levels). On the other hand, compared with expressing immunosuppressive molecules alone, it can further significantly reduce the risk of immune rejection of CAR-T cells, improve their survival rate, and thus enhance the efficacy of CAR-T cells in tumor suppression.

[0119] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Those skilled in the art will appreciate that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An engineered cell having the following characteristics: (i) expression of at least one endogenous gene selected from the group consisting of Fas, TNFR1, DR3, DR4, DR5, TGFBR1, TGFBR2 is downregulated; and (ii) expressing an exogenous immunosuppressive molecule, wherein the immunosuppressive molecule comprises one or more immunosuppressive protein binding domains, a transmembrane domain, and a co-stimulatory domain and does not comprise a primary signaling domain, wherein the immunosuppressive protein binding domain binds to an immunosuppressive protein selected from the group consisting of PD1, NKG2A, FasL, and CLTA4.

2. The engineered cell of claim 1, wherein the immunosuppressive protein binding domain comprises an anti-PD1 antibody, an anti-NKG2A antibody, an anti-FasL antibody, an anti-CTLA4 antibody, a PDL1 extracellular region, a PDL2 extracellular region, an HLA-E extracellular region, a Fas extracellular region, a CD80 extracellular region, a CD86 extracellular region, or a combination thereof.

3. The engineered cell of claim 1 or 2, wherein the transmembrane domain is selected from the transmembrane domains of the following proteins: TCRα chain, TCRβ chain, TCRγ chain, TCRδ chain, CD3ζ subunit, CD3ε subunit, CD3γ subunit, CD3δ subunit, CD28, CD45, CD4, CD5, CD8a, CD9, CD16, CD22, CD33, CD37, CD47, CD64, CD80, CD86, CD94, CD134, CD137, CD154, KIRDS2, OX40, CD2, CD27, CD18, ICOS, 4-1BB, GITR, CD40, BAFFR, HVEM, SLAMF7, NKp80, CD160, BCMA, IL-2Rβ, IL-2Rγ, IL-7R a, ITGA1, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CDl ld, ITGAE, CD103, ITGAL, CDl la, LFA-1, ITGAM, CDl lb, ITGAX, CDl lc, ITGB1, CD29, ITGB2, CD18, LFA-1, ITGB7, TNFR2, DNAM1, SLAMF4, CD84, CD96, CEACAM1, CRT AM, Ly9, CD160, PSGL1, CDIOO, SLAMF6, SLAMF1, SLAMF8, CD162, LTBR, ​​PAG / Cbp, NKp44, NKp30, NKp46, NKG2D or NKG2C.

4. The engineered cell of any one of claims 1-3, wherein the costimulatory domain is selected from the intracellular region of the following proteins: LTB, CD94, TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, CARD11, CD2, CD7, CD8, CD18, CD27, CD28, CD30, CD40, CD54, CD83, CD134, 4-1BB, CD270, CD272, B7-H3, ICOS, CD357, DAP10, DAP12, LAT, NKG2C, SLP76, PD-1, LIGHT, TRIM, ZAP70, and combinations thereof.

5. The engineered cell of any one of claims 1-4, wherein the immunosuppressive molecule does not comprise the CD3ζ intracellular domain. The engineered cell of claim 1 , wherein the engineered cell expresses two exogenous immunosuppressive molecules.

7. The engineered cell of claim 6, wherein the two exogenous immunosuppressive molecules comprise binding domains that bind to different immunosuppressive proteins.

8. The engineered cell of any one of claims 1-7, further expressing a functional exogenous receptor.

9. The engineered cell of claim 8, wherein the functional exogenous receptor is selected from the group consisting of a chimeric antigen receptor, a chimeric T cell receptor, a T cell antigen coupler, and a T cell fusion protein, preferably a chimeric antigen receptor.

10. The engineered cell of claim 9, wherein the functional exogenous receptor comprises an extracellular domain that specifically recognizes an antigen. The engineered cell of claim 10 , wherein the extracellular domain comprises an antibody that specifically recognizes the antigen or a ligand of the antigen.

12. The engineered cell of claim 10, wherein the antigen is selected from the group consisting of ALK, ADRB3, AKAP-4, APRIL, ASGPR1, BCMA, B7H3, B7H4, B7H6, bcr-abl, BORIS, BST2, BAFF-R, BTLA, CD2, CD3, CD4, CD5, CD7, CD8, CD19, CD20, CD22, CD24, CD25, CD28, CD30, CD33, CD38, CD40, CD44, CD44v6, CD44v7 / 8, CD47, CD52, CD56, CD57, CD58, CD70, CD72, CD79a, CD79b, CD80, CD81, CD86, CD97, CD123, CD133, CD137, CD 138. CD151, CD171, CD179a, CD300LF, CLEC12A, CDH16, CSPG4, CS1, CLL-1, Claudin 6, Claudin18.1, Claudin18.2, CEA, CEACAM6, c-Met, CAIX, CXORF61, CA125, CYP1B1, CS1, ELF2M, EGFR, EPCAM, EGFRvIII, EphA2, ERG / TMPRSS2ETS fusion gene, ETV6-AML, EMR2, EGP2, EGP40, FAP, FAR, FBP, FLT3, FOSL1, FCRL5, FCAR, Flt3, Flt4, F rizzled, GD2, GD3, gp100, gp130, GM3, GPC2, GPC3, GPRC5D, GPR20, GloboH, GHRHR, GHR, GITR, Her2, HER3, HER-4, HMWMAA, HAVCR1, HPV E6,E7, HVEM, HIV-1Gag, HLA-A1, HLA-A2, IL6R, IL-11Ra, IL-13Ra, IGF-I receptor, LTPR, LIFRP, LRP5, IGLL1, IGF1R, KIT, Kappa Light Chain, KDR, LewisY, LMP2, LY6K, LAGE-1a, legumain, LCK, LAIR1, LILRA2, LY75, MSLN, MUC1, MUC16, MAGE-A1, MAGE3, MAD-CT-1, MelanA / MART1, ML-IAP, MYCN, mut hsp70-2, NCAM, NY-BR-1, NY-ESO-1, NA17, Notch-1-4, nAchR, NKG2D, NKG2D ligand, OY-TES1, OR51E2, OX40, PRSS21, PSCA, PD1, PD-L1, PD-L2, PSMA, Prostase, PAP, PDGFR-β, PCTA-1 / galectin 8, p53, p53 mutant, prostein, PLAC1, PANX3, PAX3, PAX5, PTCH1, RANK, RAGE-1, ROR1, Ras mutant, RhoC, RU1, RU2, Robol, SSEA-4, SSX2, SART3, Sp17, TSHR, Tn Ag, TGS5, TEM1 / CD248, TEM7R, TARP, TCRα, TCRβ, TGFBR1, TGFBR2, TNFRSF4, TWEAK-R, TLR7, TLR9, TAG72, TROP-2, Tie 2, TRP-2, TNFR1, TNFR2, TEM1, UPK2 VEGFR, WT1, XAGE1, 5T4, 8H9, αvβ6 integrin, CA9, folate receptor α, ephrin B2, tyrosinase, fucosyl GM1, o-acetyl-GD2, folate receptor β, polysialic acid, sperm protein 17, survivin and telomerase, sarcoma translocation breakpoints, human telomerase / hTERT, androgen receptor, intestinal carboxylesterase, cyclin B1, fibronectin, tenascin, oncofetal variant of tumor necrosis, or any combination thereof.

13. The engineered cell of claim 8, wherein the functional exogenous receptor is a chimeric antigen receptor that targets CD19, CD7, CD19, CD20, CD22, CD30, CD33, CD38, CD123, CD138, CD171, MUC1, MSLN, AFP, folate receptor alpha, CEA, PSCA, PSMA, Her2, EGFR, IL-13Ra, GD2, NKG2D, Claudin18.2, ROR1, EGFRvIII, CS1, BCMA, or GPRC5D.

14. The engineered cell of any one of claims 1-13, wherein expression of at least one endogenous TCR / CD3 gene of the engineered cell is inhibited or silenced.

15. The engineered cell of claim 14, wherein the TCR / CD3 gene is selected from the group consisting of TRAC, TRBC, CD3γ, CD3δ, CD3ε, CD3ζ, and combinations thereof.

16. The engineered cell of claim 1, wherein the HLA class I gene and / or HLA class II gene of the engineered cell is not modified.

17. The engineered cell of claim 1, wherein expression of at least one endogenous HLA class I gene and / or HLA class II gene of the engineered cell is downregulated.

18. The engineered cell of any one of claims 1-17, wherein the engineered cell is a B cell, a T cell, a macrophage, a dendritic cell, a monocyte, a NK cell, or a NKT cell.

19. The engineered immune cell of claim 18, wherein the engineered cell is a CD4+CD8+T cell, a CD4+T cell, a CD8+T cell, a CD4-CD8-T cell, a tumor infiltrating cell, a memory T cell, a naive T cell, a γδ-T cell, or an αβ-T cell.

20. The engineered cell of any one of claims 1-19, wherein the engineered cell is derived from umbilical cord blood stem cells, progenitor cells, bone marrow stem cells, hematopoietic stem cells, adult stem cells, embryonic stem cells, pluripotent stem cells, or iPSCs.

21. A pharmaceutical composition comprising the engineered immune cell according to any one of claims 1 to 20, and one or more pharmaceutically acceptable excipients.

22. The pharmaceutical composition of claim 21, wherein the pharmaceutical composition is used to treat cancer, infection or autoimmune disease.

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