Novel anti-LILRB2 antibodies and uses thereof

Abstract

The present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof, pharmaceutical compositions comprising the same, and uses thereof.

Description

[Technical Field]

[0001] The present disclosure relates generally to novel anti-LILRB2 antibodies and antigen-binding fragments thereof and uses thereof. [Background technology]

[0002] Current immune checkpoint blockade therapies, such as programmed cell death protein 1 and ligand 1 (PD-1 / PD-L1), have been successful in treating certain types of cancer. However, most cancer patients either do not respond to these checkpoint blockade drugs or relapse after treatment. Developing approaches to identify more effective immune checkpoint targets is crucial for the successful application of immunotherapy to a wider range of cancers. Some immune cell populations, such as myeloid cells, are known to be more abundant than T cells in the tumor microenvironment (TME). These immune cells have the ability to kill tumor cells and prime and reactivate T cells. However, they become dysfunctional in the TME and transform into immunosuppressive cells that promote tumor development and suppress immune surveillance. These immunosuppressive cells may include myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and tolerogenic dendritic cells (toDCs), neutrophils, eosinophils, etc. Immunoinhibitory receptors on these cells may play an important role in their immunosuppressive function. Reprogramming, eliminating, or blocking the trafficking of these immunosuppressive cells has attracted attention as an anti-cancer therapeutic strategy (Deng M et al., Antib Ther., 2021 Feb 9;4(1):16-33).

[0003] The leukocyte immunoglobulin-like receptor (LILR, LIR, ILT, CD85) family is divided into two classes: inhibitory LILR subfamily B (LILRB1-5) and activating LILR subfamily A (LILRA1-6) (van der Touw W et al., Cancer Immunol Immunother., 2017 Aug;66(8):1079-1087). LILRBs are specific to primates and humans, and only two homologs have been identified in mice: paired immunoglobulin-like receptor B (PirB) and gp49B1. LILRBs signal through intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which recruit phosphatases to negatively regulate immune activation. LILRB is known to be expressed in myeloid cells and certain other hematopoietic cells (Mori et al., J Immunol., 2008 Oct 1; 181(7):4742-51). Activation of LILRB signaling in immune cells may contribute to immune evasion. In addition, some members of the LILRB family are highly expressed in AML cells, and their expression is negatively correlated with the overall survival of human AML patients.

[0004] Leukocyte immunoglobulin-like receptor subfamily B member 2 (LILRB2) is a protein encoded by the LILRB2 gene in humans. LILRB2 belongs to the LILR subfamily B class and contains four extracellular immunoglobulin domains, a transmembrane domain, and three cytoplasmic ITIMs. It is expressed in hematopoietic stem cells, monocytes, macrophages, DCs, neutrophils, basophils, platelets, and activated CD4+ T cells, as well as in vitro-cultured endothelial cells, mast cell precursors, and osteoclasts. LILRB2 has been proposed as a potential target for tumor immunotherapy. It is expressed in tumor-associated macrophages and has been shown to negatively regulate immune responses in tumors. Blockade of LILRB2 reprograms tumor amniotic membrane proteins (TAMs) to a proinflammatory phenotype, suppresses Treg infiltration, and enhances the efficacy of immune checkpoint inhibitors. LILRB2 has also been found to be overexpressed in leukemia, breast cancer, non-small cell lung cancer, and pancreatic cancer, contributing to tumor progression. Preclinical studies have shown that LILRB2 antagonism enhances macrophage maturation and activation.

[0005] There is still a need for novel anti-LILRB2 antibodies. Summary of the Invention

[0006] Throughout this disclosure, the articles "a," "an," and "the" are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an antibody" means one antibody or multiple antibodies.

[0007] In one aspect, the present disclosure provides an antibody or antigen-binding fragment thereof that binds to LILRB2, one, two or three heavy chain complementarity determining regions (HCDR1, HCDR2 and / or HCDR3) contained within any one of the heavy chain variable (VH) region sequences selected from the group consisting of SEQ ID NOs: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231 and 239, and / or The present invention provides an antibody or antigen-binding fragment thereof, comprising one or two or three light chain complementarity determining regions (LCDR1, LCDR2 and / or LCDR3) contained within any one of the light chain variable (VL) region sequences selected from the group consisting of SEQ ID NOs: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232 and 240. In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 97, 98, 99, 100, 101, 102, 105, 106, 107, 108, 109, 110, 113, 114, 115, 116, 117, 118, 121, 122, 123, 124, 125, 126, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 1 34, 137, 138, 139, 140, 141, 142, 145, 146, 147, 148, 149, 150, 153, 154, 155, 156, 157, 158, 161, 162, 163, 164, 165, 166, 169, 170, 171, 172, 173, 174, 177, 178, 179, 180, 181, 182, 185, 186, 187, 188, 189, 190, 193, 194, 195, and at least one heavy or light chain complementarity determining region (CDR) comprising an amino acid sequence selected from the group consisting of: 196, 197, 198, 201, 202, 203, 204, 205, 206, 209, 210, 211, 212, 213, 214, 217, 218, 219, 220, 221, 222, 225, 226, 227, 228, 229, 230, 233, 234, 235, 236, 237, and 238.

[0008] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 97, 98, 99, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139, 145, 146 , 147, 153, 154, 155, 161, 162, 163, 169, 170, 171, 177, 178, 179, 185, 186, 187, 193, 194, 195, 201, 202, 203, 209, 210, 211, 217, 218, 219, 225, 226, 227, 233, 234 and 235.

[0009] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 100, 101, 102, 108, 109, 110, 116, 117, 118, 124, 125, 126, 132, 133, 134, 140, 141, and a VL region comprising one or two or three of LCDR1, LCDR2 and LCDR3 comprising an amino acid sequence selected from the group consisting of 142, 148, 149, 150, 156, 157, 158, 164, 165, 166, 172, 173, 174, 180, 181, 182, 188, 189, 190, 196, 197, 198, 204, 205, 206, 212, 213, 214, 220, 221, 222, 228, 229, 230, 236, 237 and 238.

[0010] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. an HCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, 113, 121, 129, 137, 145, 153, 161, 169, 177, 185, 193, 201, 209, 217, 225, and 233; ii. an HCDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 98, 106, 114, 122, 130, 138, 146, 154, 162, 170, 178, 186, 194, 202, 210, 218, 226 and 234, and iii. comprises an HCDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227 and 235.

[0011] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. an LCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 100, 108, 116, 124, 132, 140, 148, 156, 164, 172, 180, 188, 196, 204, 212, 220, 228, and 236; ii. an LCDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, 141, 149, 157, 165, 173, 181, 189, 197, 205, 213, 221, 229, and 237; and iii. Contains an LCDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 102, 110, 118, 126, 134, 142, 150, 158, 166, 174, 182, 190, 198, 206, 214, 222, 230 and 238.

[0012] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 2, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 3; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11; iii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 18, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 19; iv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27; v. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 34, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 35; vi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 42, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 43; vii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 50, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 51; viii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59; ix. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67; x. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 74, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 75; xi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91; xiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 98, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 99; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115; xvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 122, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 123; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131; xviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 138, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 139; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155; xxi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 162, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 163; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219; xxix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, or xxx. Comprises HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 234, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 235.

[0013] In some embodiments, the antibody or antigen-binding fragment thereof of the present disclosure: i. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 6; ii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 14; iii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 22; iv. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 30; v. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 38; vi. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 46; vii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 54; viii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 62; ix. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 70; x. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 78; xi. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 86; xii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 102; xiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 126; xvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 142; xix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 166; xxii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 238.

[0014] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 2, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 3, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 6; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 14; iii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 18, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 19, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 22; iv. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 26, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 27, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 30; v. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 34, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 35, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 38; vi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 43, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 46; vii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 50, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 51, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 54; viii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 62; ix. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 70; x. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 74, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 75, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 78; xi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 86; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 98, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 99, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 102; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 122, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 123, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 126; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 138, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 139, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 142; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 162, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 163, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 166; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. Comprises HCDR1 having the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 having the amino acid sequence set forth in SEQ ID NO: 234, HCDR3 having the amino acid sequence set forth in SEQ ID NO: 235, LCDR1 having the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 having the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 having the amino acid sequence set forth in SEQ ID NO: 238.

[0015] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise an antibody or antigen-binding fragment thereof selected from the group consisting of an amino acid sequence set forth in SEQ ID NOs: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, or 239. or a homologous sequence thereof having at least 80% sequence identity to SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231 or 239.

[0016] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise an antibody or antigen-binding fragment thereof selected from the group consisting of an amino acid sequence set forth in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, or 240. or a homologous sequence thereof having at least 80% sequence identity to SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232 or 240.

[0017] In some embodiments, an antibody or antigen-binding fragment thereof provided herein comprises a VH / VL amino acid sequence pair selected from the group consisting of SEQ ID NOs: 7 / 8, 15 / 16, 23 / 24, 31 / 32, 39 / 40, 47 / 48, 55 / 56, 63 / 64, 71 / 72, 79 / 80, 87 / 88, 95 / 96, 103 / 104, 111 / 112, 119 / 120, 127 / 128, 135 / 136, 143 / 144, 151 / 152, 159 / 160, 167 / 168, 175 / 176, 183 / 184, 191 / 192, 199 / 200, 207 / 208, 215 / 216, 223 / 224, 231 / 232, and 239 / 240.

[0018] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise one or more amino acid residue substitutions or modifications, while maintaining binding affinity to LILRB2. In some embodiments, at least one of the substitutions or modifications is in one or more of the CDR sequences of the VH or VL region. In some embodiments, at least one of the substitutions or modifications is in one or more non-CDR sequences of the VH or VL region. In some embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise one or more non-naturally occurring amino acid (NNAA) substitutions. In some embodiments, the NNAA is conjugable.

[0019] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. capable of specifically binding to human LILRB2; ii. capable of binding to human LILRB2 and rhesus monkey LILRB2; iii. has a higher, lower or equivalent binding affinity for human LILRB2 compared to reference antibodies J-19.h1, B2-19 or 1E1; iv. capable of binding to human LILRB2 and human LILRB1; v. have a higher, lower, or equivalent binding affinity for human LILRB1 compared to reference antibody 15G8 or Hz73D1.v1; vi. Capable of functionally blocking the interaction between LILRB2 and its ligand; vii. It is capable of increasing TNF-α secretion and / or CD86 expression in immature macrophages; viii. It can suppress M2-like polarization of macrophages to rescue T cell activation; ix. Ability to enhance anti-CD47-mediated macrophage phagocytosis; x the ability to enhance T cell or myeloid cell inflammatory cytokine secretion (e.g., GM-CSF secretion and / or TNF-α secretion); xi. It is capable of inhibiting the polarization of monocytes into a macrophage-like immunosuppressive phenotype; xii. be able to reverse MDSC-mediated suppression of T cell activation; and xiii. capable of rescuing T cell activity from suppression by immunosuppressive myeloid cells when used in combination with an anti-PD-1 or anti-PD-L1 agent.

[0020] In another aspect, the present disclosure provides an antibody or antigen-binding fragment thereof that competes with the above-described antibody or antigen-binding fragment thereof for binding to LILRB2.

[0021] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are chimeric, humanized, or human antibodies or antigen-binding fragments thereof.

[0022] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are labeled antibodies, bivalent antibodies, anti-idiotypic antibodies, or fusion proteins.

[0023] In some embodiments, an antibody or antigen-binding fragment thereof provided herein is a diabody, Fab, Fab', F(ab')2, Fd, Fv fragment, disulfide-stabilized Fv fragment (dsFv), (dsFv)2, bispecific dsFv (dsFv-dsFv'), disulfide-stabilized diabody (ds diabody), single-chain antibody molecule (scFv), scFv dimer (bivalent diabody), camelized single domain antibody, nanobody, domain antibody, or bivalent domain antibody.

[0024] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise an Fc region. In some embodiments, the Fc region is a human immunoglobulin (Ig) Fc region. In some embodiments, the Fc region is a human IgG Fc region. In some embodiments, the Fc region is derived from human IgG1, IgG2, IgG3, or IgG4. In some embodiments, the Fc region is derived from human IgG4. In some embodiments, the Fc region is derived from human IgG4 and contains a S228P (EU numbering) mutation. In some embodiments, the Fc region comprises the amino acid sequence set forth in SEQ ID NO: 283.

[0025] In some embodiments, the light chain of an antibody or antigen-binding fragment thereof provided herein is a λ light chain or a κ light chain.

[0026] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are bispecific or multispecific antibodies or antigen-binding fragments thereof. In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of specifically binding to one or more additional antigens other than LILRB2 or a second epitope on LILRB2.In some embodiments, the one or more additional antigens other than LILRB2 are CD3, CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, FLT3, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP, TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, D LL3, HER-2, C10orf54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1 / 2, PAK4, NAMPT, ATR, EGFR, FGFR, VEGF, c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD 2, CD7, CD16, CD19, CD20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80(B7-1), CD86(B7-2), CD40, CD40L(CD154), CD47, SIR Pα, CD122, CD137, CD137L, OX40 (CD134), OX40L (CD252), BCMA (e.g. BCMA02), PSMA, CLDN18 (e.g. CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAM F7, HVEM, BAFFR, ICAM-1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD2) 72), CD160, CTLA-4 (CD152), GPRC5D, IDO1, IDO2, TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), LILRB1, LILRB3, LILRB4, LILRB5, FLT3L, TLR3, CLEC9A, DEC-205, STING, IL-12, IDO, and TGFβ.

[0027] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are linked to one or more conjugate moieties. In some embodiments, the conjugate moieties comprise clearance modifiers, chemotherapeutic agents, toxins, radioisotopes, lanthanides, detectable labels, DNA alkylating agents, topoisomerase inhibitors, tubulin binding agents, purification moieties, or other anti-cancer drugs. In some embodiments, the conjugate moieties are covalently attached directly or via a linker.

[0028] In another aspect, the present disclosure provides a chimeric antigen receptor comprising an antibody or antigen-binding fragment thereof provided herein, a transmembrane region, and an intracellular signaling region. In some embodiments, the transmembrane region comprises the transmembrane region of CD3, CD4, CD8, or CD28. In some embodiments, the intracellular signaling region is selected from the group consisting of CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, a TLR intracellular signaling region sequence, or a combination thereof. In some embodiments, the antigen-binding fragment of the chimeric antigen receptor is an scFv. In some embodiments, the chimeric antigen receptor is transplanted into allogeneic, autologous, or xenogeneic cells. In some embodiments, the chimeric antigen receptor is transplanted into immune effector cells. In some embodiments, the chimeric antigen receptor is transplanted into T cells, natural killer cells, macrophages, or tumor-infiltrating lymphocytes.

[0029] In another aspect, the present disclosure provides a pharmaceutical composition comprising an antibody or antigen-binding fragment thereof, and / or chimeric antigen receptor of the present disclosure and one or more pharmaceutically acceptable carriers.

[0030] In another aspect, the present disclosure provides an isolated polynucleotide encoding an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor of the present disclosure.

[0031] In another aspect, the present disclosure provides a vector comprising an isolated polynucleotide of the present disclosure.

[0032] In another aspect, the present disclosure provides a host expression system comprising a vector of the present disclosure or having a polynucleotide of the present disclosure incorporated into its genome. In some embodiments, the host expression system of the present disclosure is a microorganism, yeast, or mammalian cell. In some embodiments, the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis. In some embodiments, the yeast is Saccharomyces. In some embodiments, the mammalian cell is selected from the group consisting of COS, CHO-S, CHO-K1, HEK-293, and 3T3 cells.

[0033] In another aspect, the present disclosure provides a virus comprising the vector of the present disclosure.

[0034] In another aspect, the present disclosure provides a kit comprising an antibody or antigen-binding fragment thereof of the present disclosure and / or a chimeric antigen receptor of the present disclosure and / or a pharmaceutical composition of the present disclosure, and a second therapeutic agent.

[0035] In another aspect, the present disclosure provides a method for expressing an antibody or antigen-binding fragment thereof and / or a chimeric antigen receptor of the present disclosure, the method comprising culturing a host expression system of the present disclosure under conditions in which the antibody or antigen-binding fragment thereof or the chimeric antigen receptor of the present disclosure is expressed.

[0036] In another aspect, the present disclosure provides a method for treating, preventing, or alleviating a disease, disorder, or condition in a subject, comprising administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure.

[0037] In another aspect, the present disclosure provides use of an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure in the manufacture of a medicament for treating a LILRB2-related disease, disorder, or condition in a subject.

[0038] In another aspect, the present disclosure provides use of an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure in the manufacture of a diagnostic reagent for diagnosing a LILRB2-related disease, disorder, or condition.

[0039] In some embodiments, the disease, disorder, or condition is an immune disease, an inflammatory disease, cancer, or a neurological disease. In some embodiments, the cancer is a solid tumor or a hematological tumor. In some embodiments, the disease, disorder, or condition is a LILRB2-expressing B-cell cancer. In some embodiments, the disease, disorder, or condition is Kawasaki disease, toxoplasmosis, multiple sclerosis, systemic lupus erythematosus, lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), lung adenocarcinoma, lung squamous cell carcinoma, or Lewis lung carcinoma), peritoneal cancer, carcinoid cancer, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), cancer of the anal region (e.g., anal squamous cell carcinoma), Gastric cancer (e.g., gastrointestinal cancer), esophageal cancer, colon cancer, breast cancer, uterine cancer, liver cancer (e.g., hepatoblastoma, hepatocellular carcinoma / hepatoma, or hepatoma), bile duct cancer, sarcoma, colorectal cancer, fallopian tube cancer, salivary gland cancer, cervical cancer, endometrial or uterine cancer, osteosarcoma, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, thyroid cancer, parathyroid cancer, adrenal cancer, nasopharyngeal cancer, soft tissue sarcoma, polycythemia vera, urethral cancer, penile cancer, kidney or ureter cancer (e.g., rhabdoid tumor of the kidney), cutaneous T-cell lymphoma, medulloblastoma, nephroblastoma, myelodysplastic syndrome, chronic and Non-chronic myeloproliferative disorders, choroid plexus papilloma, renal cell carcinoma, renal pelvic carcinoma, central nervous system (CNS) tumors, soft tissue sarcomas (e.g., rhabdomyosarcoma, fibrosarcoma, Kaposi's sarcoma), spinal axis tumors, gliomas (e.g., ependymoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma, eye cancer (e.g., retinoblastoma), brain stem glioma, or mixed glioma such as oligoastrocytoma), brain tumors (e.g., glioblastoma / glioblastoma multiforme (GBM), non-glioblastoma brain tumor, or meningioma), melanoma (e.g., cutaneous melanoma or intraocular melanoma) , thrombocythemia, mesothelioma, mycosis fungoides, Sezary syndrome, idiopathic myelofibrosis, solitary plasmacytoma, vestibular schwannoma, Ewing's sarcoma, chondrosarcoma, MYH-associated polyposis, pituitary adenoma, childhood cancers such as childhood sarcomas (e.g., neuroblastoma, rhabdomyosarcoma, and osteosarcoma), blood cancers, Hodgkin's lymphoma, non-Hodgkin's lymphoma, leukemia (e.g., lymphocytic / lymphoblastic leukemia), chronic or acute leukemia, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CLL),The disease, disorder, or condition is selected from the group consisting of acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), acute myelogenous leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g., relapsed or refractory multiple myeloma), T-cell or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary mediastinal large B-cell lymphoma, follicular lymphoma (FL), and primary mediastinal B-cell lymphoma. In some embodiments, the disease, disorder, or condition is acute myeloid leukemia. In some embodiments, the disease, disorder, or condition is chronic myelomonocytic leukemia.

[0040] In some embodiments, the subject is a human.

[0041] In some embodiments, the administration is via a parenteral route, including subcutaneous, intraperitoneal, intravenous, intramuscular, or intradermal injection, or a non-parenteral route, including transdermal, oral, intranasal, intraocular, sublingual, rectal, or topical.

[0042] In some embodiments, the method for treating, preventing, or alleviating a disease, disorder, or condition in a subject further comprises administering an additional therapeutic agent to the subject in need thereof. In some embodiments, the additional therapeutic agent is selected from the group consisting of an active agent, an imaging agent, a cytotoxic agent, and an angiogenesis inhibitor, a kinase inhibitor, a costimulatory molecule agonist, a co-inhibitory molecule blocker, an adhesion molecule blocker, an anti-cytokine antibody or functional fragment thereof, a detectable label or reporter, an antibacterial agent, a gene editing agent, a beta agonist, a viral RNA inhibitor, a polymerase inhibitor, an interferon, and a microRNA. In some embodiments, the additional therapeutic agent is an anti-PD-1 antibody, an anti-PD-L1 antibody, or an antigen-binding fragment thereof. In some embodiments, the additional therapeutic agent is atezolizumab. In some embodiments, the additional therapeutic agent is administered to the subject in need thereof before, after, or simultaneously with the antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure.

[0043] In another aspect, the present disclosure provides a method for modulating LILRB2 activity in a LILRB2-expressing cell, the method comprising exposing the LILRB2-expressing cell to an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure.

[0044] In some embodiments, the LILRB2-expressing cell is a hematopoietic stem cell, a dendritic cell, a monocyte, a macrophage, a neutrophil, a basophil, a platelet, a precursor mast cell, an endothelial cell, a neuron, or an osteoclast.

[0045] In another aspect, the present disclosure provides a method of inducing or enhancing phagocytosis of a target cell in vivo or in vitro, comprising exposing the target cell to an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure. In some embodiments, the target cell is an antigen-presenting cell, a cancer cell, or a cell infected with a pathogen.

[0046] In another aspect, the present disclosure provides a method for blocking the interaction of LILRB2 with its ligand, the method comprising exposing LILRB2 or a cell expressing LILRB2 to an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure. In some embodiments, the ligand for LILRB2 is HLA-G. In some embodiments, the LILRB2 is expressed in or on a cell. In some embodiments, the cell is selected from a hematopoietic stem cell, a dendritic cell, a monocyte, a macrophage, a neutrophil, a basophil, a platelet, a T cell, a B cell, a Treg, a precursor mast cell, an endothelial cell, a neuron, or an osteoclast.

[0047] In another aspect, the present disclosure provides a method of inducing TNF-α production and / or CD86 expression, the method comprising exposing immature macrophages to an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure.

[0048] In another aspect, the present disclosure provides a method of inhibiting M2-like polarization of immature macrophages, comprising exposing the immature macrophages to an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure. In some embodiments, the purpose of the inhibition is to rescue T cell activation.

[0049] In another aspect, the present disclosure provides a method of enhancing anti-CD47 agent-mediated phagocytosis of a target cell, the method comprising exposing the target cell to an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure.

[0050] In another aspect, the present disclosure provides use of an antibody or antigen-binding fragment thereof, chimeric antigen receptor and / or pharmaceutical composition of the present disclosure in combination with an anti-CD47 agent to induce or enhance phagocytosis of target cells.

[0051] In another aspect, the present disclosure provides a kit comprising (a) an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure, and (b) an anti-CD47 agent, which is useful for inducing or enhancing phagocytosis of target cells.

[0052] In some embodiments, the target cell is an antigen-presenting cell, a macrophage, a cancer cell, or a cell infected with a pathogen. In some embodiments, the anti-CD47 agent is an anti-CD47 antibody or an antigen-binding fragment thereof.

[0053] In another aspect, the present disclosure provides use of an antibody or antigen-binding fragment thereof, chimeric antigen receptor, and / or pharmaceutical composition of the present disclosure in combination with an anti-PD-1 or PD-L1 agent in rescuing T cell activity from suppression by immunosuppressive myeloid cells. In some embodiments, the anti-PD1 or PD-L1 agent is an anti-PD1 or PD-L1 antibody or antigen-binding fragment thereof. In some embodiments, the anti-PD-L1 agent is atezolizumab.

[0054] In another aspect, the present disclosure provides a kit useful for rescuing T cell activity from suppression by immunosuppressive myeloid cells, comprising (a) an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition of the present disclosure, and (b) an anti-PD1 or PD-L1 agent. In some embodiments, the anti-PD1 or PD-L1 agent is an anti-PD1 or PD-L1 antibody or antigen-binding fragment thereof. In some embodiments, the anti-PD-L1 agent is atezolizumab.

[0055] In another aspect, the present disclosure provides a method for detecting the presence or amount of LILRB2 in a sample, the method comprising contacting the sample with an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure, and determining the presence or amount of LILRB2 in the sample.

[0056] In another aspect, the present disclosure provides a method for diagnosing a LILRB2-related disease or condition in a subject, the method comprising: a) contacting a sample collected from the subject with an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure; b) determining the presence or amount of LILRB2 in the sample; and c) correlating the presence or amount of LILRB2 with the presence or status of the LILRB2-related disease or condition in the subject.

[0057] In another aspect, the present disclosure provides a kit comprising an antibody or antigen-binding fragment thereof and / or pharmaceutical composition and / or chimeric antigen receptor of the present disclosure, and useful for detecting LILRB2, optionally recombinant LILRB2, cell surface-expressed LILRB2, or LILRB2-expressing cells. [Brief explanation of the drawings]

[0058] [Figure 1] FIG. 1 shows the binding affinities of selected antibodies, reference antibodies (J-19.h1 and 1E1), and a negative control (IgG4) to HEK293F-hLILRB2 cells as measured by FACS assay. [Figure 2] FIG. 2 shows the binding affinities of selected antibodies, reference antibodies (J-19.h1 and 1E1), and a negative control (IgG4) to HEK293F-hLILRB2 cells as measured by FACS assay. [Figure 3] FIG. 3 shows the binding affinities of selected chimeric antibodies and a reference antibody (15G8) to HEK293T-hLILRB1 cells as measured by FACS assay. [Figure 4] FIG. 4 shows the cross-reactivity of selected chimeric antibodies to HEK293T-monkey LILRB2 as determined by FACS assay. [Figure 5]Figure 5 shows the blocking of HLA-G / LILRB2 interaction by selected chimeric antibodies, reference antibodies (J-19.h1 and 1E1), and a negative control (IgG4) in a stable chimeric receptor reporter cell line (Jurkat-hLILRB2 ECD-PILRβ TM-PILRβ ICD-DAP12-NFAT-Luc cells). [Figure 6] FIG. 6 shows the LPS-induced inflammatory response (measured by TNF-α secretion) in immature macrophages treated with selected chimeric antibodies, a reference antibody (J-19.h1) and a negative control (IgG4). [Figure 7] FIG. 7 shows the inhibition of immature macrophages towards M2-like polarization (measured by CD25 expression on CD4+ T cells) by selected chimeric antibodies, reference antibodies (J-19.h1 and 1E1) and a negative control (IgG4). [Figure 8] FIG. 8 shows the anti-CD47-mediated macrophage phagocytic effect induced by selected anti-LILRB2 / 1 antibodies, reference antibodies (15G8 and Hz73D1.v1) and a negative control (IgG4). [Figure 9] Figure 9 shows the blocking activity of selected chimeric antibodies, reference antibodies (15G8 and Hz73D1.v1), and a negative control (IgG4) against HLA-G / LILRB1 interaction in a stable chimeric receptor reporter cell line (Jurkat-hLILRB1 ECD-PILRβ TM-PILRβ ICD-DAP12-NFAT-Luc cells). [Figure 10] FIG. 10 shows the blocking activity of selected chimeric antibodies and reference antibodies (B2-19 and 1E1) against HLA-G / LILRB2 interaction or HLA-A, B, C / LILRB2 interaction in Jurkat NFAT reporter cells. [Figure 11] FIG. 11 shows the blocking activity of selected chimeric and reference antibodies (15G8 and Hz73D1.v1) on HLA-G / LILRB1 interaction in Jurkat NFAT reporter cells. [Figure 12]FIG. 12 shows the LPS-induced inflammatory response (measured by CD86 expression) in immature macrophages treated with selected chimeric antibodies, reference antibodies (J-19.h1 and B2-19) and a negative control (IgG4). [Figure 13] FIG. 13 shows the effect of selected anti-LILRB2 antibodies on bone marrow-derived cytokine secretion (GM-CSF secretion and TNF-α secretion) by primary human PBMCs. [Figure 14A] FIG. 14A shows the effect of selected anti-LILRB2 antibodies, reference antibodies (J-19.h1 and B2-19), and a negative control (IgG4) in inhibiting the polarization of monocytes toward a macrophage-like immunosuppressive phenotype. [Figure 14B] FIG. 14B shows the effect of selected anti-LILRB2 antibodies, reference antibodies (J-19.h1 and B2-19), and a negative control (IgG4) in inhibiting the polarization of monocytes toward a macrophage-like immunosuppressive phenotype. [Figure 15] FIG. 15 shows the inhibition of M2-like polarization of immature macrophages (measured by IFNγ production) by selected chimeric antibodies, reference antibodies (J-19.h1, B2-19 and 1E1) and a negative control (IgG4). [Figure 16] FIG. 16 shows the reversal of the inhibition of MDSC-mediated T cell activation by selected chimeric antibodies, reference antibodies (J-19.h1 and B2-19) and a negative control (IgG4). [Figure 17] Figure 17 shows the inhibition of M2-like polarization of macrophages (as measured by IFNγ production) by combinations of PD-L1 antibodies with selected chimeric antibodies, a reference antibody (B2-19), and a negative control (IgG4). [Figure 18] Figure 18 shows the antitumor efficacy of different doses of chimeric antibody ch45-F1-F5-A2 (10 mg / kg, 6 mg / kg, 3 mg / kg), a reference antibody (B2-19), and a negative control (IgG4) in a syngeneic Lewis lung carcinoma (LLC1) model in LILRB2 transgenic mice. [Figure 19]FIG. 19 shows the anti-tumor efficacy of chimeric antibodies (ch33-E3-C9-G8 and ch45-F1-F5-A2) and a negative control (IgG4) in the humanized mouse breast cancer MDA-MB-231 model. [Figure 20A] FIG. 20A shows the competitive binding of several chimeric anti-LILRB2 antibodies with the reference antibody B2-19. [Figure 20B] FIG. 20B shows the competitive binding of several chimeric anti-LILRB2 antibodies with the reference antibody J-19.h1. [Figure 20C] FIG. 20C shows the competitive binding of ch45-F1-F5-A2 with ch19-H6-A9-E4. DETAILED DESCRIPTION OF THE INVENTION

[0059] The following description of the present disclosure is intended to merely illustrate various embodiments of the present disclosure. Therefore, the specific modifications discussed are not intended to limit the scope of the present disclosure. It will be apparent to those skilled in the art that various equivalents, changes, and modifications can be made without departing from the scope of the present disclosure, and it is understood that such equivalent embodiments are incorporated herein. All references cited herein, including publications, patents, and patent applications, are incorporated herein by reference in their entirety. definition

[0060] The term "antibody," as used herein, includes any immunoglobulin, monoclonal, polyclonal, multivalent, bivalent, monovalent, multispecific, or bispecific antibody that binds to a specific antigen. A naturally occurring, intact antibody contains two heavy (H) chains and two light (L) chains. Mammalian heavy chains are classified as α, δ, ε, γ, and μ, with each heavy chain containing a variable region (VH) and a first, second, third, and optionally, fourth constant region (CH1, CH2, CH3, and CH4, respectively). Mammalian light chains are classified as λ or κ, with each light chain containing a variable region (VL) and a constant region. Antibodies are "Y" shaped, with the tail of the Y containing the second and third constant regions of two heavy chains joined together via disulfide bonds. Each arm of the Y contains the variable region and first constant region of a single heavy chain bound to the variable and constant region of a single light chain. The variable regions of the light and heavy chains are responsible for antigen binding. The variable regions in both chains generally contain three highly variable loops called complementarity-determining regions (CDRs) (light chain CDRs include LCDR1, LCDR2, and LCDR3, while heavy chain CDRs include HCDR1, HCDR2, and HCDR3). The three CDRs are interposed between adjacent sections known as framework regions (FRs), which are more highly conserved than the CDRs and form a scaffold supporting the hypervariable loops (light chain FRs include LFR1, LFR2, LFR3, and LFR4, while heavy chain FRs include HFR1, HFR2, HFR3, and HFR4). The constant regions of the heavy and light chains are not involved in antigen binding but exhibit various effector functions. Antibodies are classified into classes based on the amino acid sequence of their heavy chain constant regions. The five major classes or isotypes of antibodies are IgA, IgD, IgE, IgG, and IgM, characterized by the presence of α, δ, ε, γ, and μ heavy chains, respectively. Some of the major antibody classes are divided into subclasses, such as IgG1 (γ1 heavy chain), IgG2 (γ2 heavy chain), IgG3 (γ3 heavy chain), IgG4 (γ4 heavy chain), IgA1 (α1 heavy chain), or IgA2 (α2 heavy chain).

[0061] In certain embodiments, the antibodies provided herein encompass any antigen-binding fragment thereof. The term "antigen-binding fragment," as used herein, refers to an antibody fragment formed from a portion of an antibody comprising one or more (e.g., 1, 2, 3, 4, 5, or 6) CDRs, or any other antibody fragment that binds to an antigen but does not comprise an intact native antibody structure. Examples of antigen-binding fragments include, without limitation, diabodies, Fab, Fab', F(ab'), Fd, Fv fragments, disulfide-stabilized Fv fragments (dsFv), (dsFv)2, bispecific dsFv (dsFv-dsFv'), disulfide-stabilized diabodies (ds diabodies), single-chain antibody molecules (scFv), scFv dimers (bivalent diabodies), diabodies, multispecific antibodies, camelized single-domain antibodies, nanobodies, domain antibodies, or bivalent domain antibodies. An antigen-binding fragment is capable of binding to the same antigen or epitope as the parent antibody.

[0062] "Fab," with respect to an antibody, refers to the portion of an antibody consisting of a single light chain (both variable and constant regions) linked by disulfide bonds to the variable region and first constant region of a single heavy chain.

[0063] "Fab'" refers to a Fab fragment that includes part of the hinge region.

[0064] "F(ab')2" refers to a Fab' dimer.

[0065] "Fc," with respect to an antibody (e.g., of the IgG, IgA, or IgD isotype), refers to the portion of the antibody consisting of the second and third constant domains of a first heavy chain linked via disulfide bonds to the second and third constant domains of a second heavy chain. For antibodies of the IgM and IgE isotype, Fc further comprises a fourth constant domain. The Fc portion of an antibody is responsible for various effector functions, such as antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), but does not function in antigen binding.

[0066] "Fv," with respect to antibodies, refers to the minimum fragment of an antibody that contains an intact antigen-binding site. An Fv fragment consists of the variable region of a single heavy chain bound to the variable region of a single heavy chain.

[0067] A "single-chain Fv antibody" or "scFv" refers to an engineered antibody consisting of a light chain variable region and a heavy chain variable region that are connected to each other either directly or via a linker (e.g., a peptide sequence) (Huston JS et al., Proc Natl Acad Sci USA, 85:5879 (1988)).

[0068] "Single chain Fv-Fc antibody" or "scFv-Fc" refers to an engineered antibody consisting of an scFv connected to the Fc region of an antibody.

[0069] "Camelized single domain antibody," "heavy chain antibody," or "HCAb" refers to an antibody that contains two VH domains and no light chains (Riechmann L. and Muyldermans S., J Immunol Methods. Dec 10; 231(1-2):25-38 (1999); Muyldermans S., J Biotechnol. Jun; 74(4):277-302 (2001); WO94 / 04678; WO94 / 25591; U.S. Patent No. 6,005,079). Heavy chain antibodies were originally derived from camelids (camels, dromedaries, and llamas). Although lacking light chains, camelized antibodies possess a robust antigen-binding repertoire (Hamers-Casterman C. et al., Nature. Jun 3; 363(6428):446-8 (1993), Nguyen VK. et al., Immunogenetics. Apr; 54(1):39-47 (2002), Nguyen VK. et al., Immunology. May; 109(1):93-101 (2003)). The variable domain of heavy chain antibodies (VHH domain) represents the smallest known antigen-binding unit generated by the adaptive immune response (Koch-Nolte F. et al., FASEB J. Nov; 21(13):3490-8. Epub 2007 Jun 15 (2007)).

[0070] "Nanobody" refers to an antibody fragment consisting of a VHH domain from a heavy chain antibody and two constant domains, CH2 and CH3.

[0071] A "diabody" or "dAb" comprises a small antibody fragment with two antigen-binding sites, wherein these fragments are V or V+ on the same polypeptide chain. L V connected to the domain H Domaine (V H -V L or V L -V H) (see, e.g., Holliger P. et al., Proc Natl Acad Sci USA. Jul 15;90(14):6444-8 (1993), EP404097, WO93 / 11161). By using a linker that is too short to allow pairing of the two domains on the same chain, the domains are forced to pair with complementary domains on another chain, thereby generating two antigen-binding sites. The antigen-binding sites may target the same or different antigens (or epitopes). In certain embodiments, a "bispecific ds diabody" is a diabody that targets two different antigens (or epitopes).

[0072] A "domain antibody" refers to an antibody fragment containing only the variable region of a heavy chain or the variable region of a light chain. H The domains are covalently linked with a peptide linker to create a bivalent or multivalent domain antibody. H The domains may target the same or different antigens.

[0073] The term "valent," as used herein, refers to the presence of a particular number of antigen-binding sites in a given molecule. The term "monovalent" refers to an antibody or antigen-binding fragment that has only a single antigen-binding site, and the term "multivalent" refers to an antibody or antigen-binding fragment that has multiple antigen-binding sites. Thus, the terms "bivalent," "tetravalent," and "hexavalent" refer to two, four, and six antigen-binding sites, respectively, in an antigen-binding molecule. In some embodiments, an antibody or antigen-binding fragment thereof is bivalent.

[0074] As used herein, a "bispecific" antibody is an artificial antibody having fragments derived from two different monoclonal antibodies and capable of binding to two different epitopes, which may be on the same antigen or on two different antigens.

[0075] As used herein, a "multispecific" antibody refers to an antibody that specifically binds to at least two different antigens or at least two different epitopes within the same antigen. A multispecific antibody may, for example, bind to two, three, four, five, or more different antigens or different epitopes within the same antigen.

[0076] In a specific embodiment, an "scFv dimer" is a bivalent diabody or bispecific scFv (BsFv) comprising a VH-VL (linked by a peptide linker) dimerized with another VH-VL moiety, whereby the VH's of one moiety coordinates with the VL's of another moiety to form two binding sites which may target the same antigen (or epitope) or different antigens (or epitopes). In another embodiment, an "scFv dimer" is a bispecific diabody comprising VH1-VL2 (linked by a peptide linker) associated with VL1-VH2 (also linked by a peptide linker), whereby VH1 and VL1 and VH2 and VL2 coordinate, with each coordinated pair having a different antigen specificity.

[0077] "dsFv" refers to a disulfide-stabilized Fv fragment in which the link between the variable region of a single light chain and the variable region of a single heavy chain is a disulfide bond. In some embodiments, a "(dsFv)2" or "(dsFv-dsFv')" refers to a disulfide-stabilized Fv fragment in which the link between the variable region of a single light chain and the variable region of a single heavy chain is a disulfide bond. H The moieties are linked by a peptide linker (e.g., a long flexible linker) and each of the two V L In some embodiments, the dsFv-dsFv' is bispecific, with each disulfide paired heavy and light chain having a different antigen specificity.

[0078] The term "chimeric," as used herein, refers to an antibody or antigen-binding fragment in which a portion of the heavy and / or light chain is derived from one species and the remaining portion of the heavy and / or light chain is derived from another species. In an illustrative example, a chimeric antibody can contain a constant region derived from a human and a variable region derived from a non-human animal, such as a mouse. In some embodiments, the non-human animal is a mammal, such as a mouse, rat, rabbit, goat, sheep, guinea pig, or hamster.

[0079] The term "humanized," as used herein, means that an antibody or antigen-binding fragment contains CDRs derived from a non-human animal, FR regions derived from a human, and, if applicable, constant regions derived from a human. The CDRs of the humanized antibodies provided in this disclosure may contain mutations compared to the CDRs of their parent antibodies.

[0080] The term "affinity," as used herein, refers to the strength of the non-covalent interactions between an immunoglobulin molecule (i.e., an antibody) or an antigen-binding fragment thereof and an antigen.

[0081] An antibody or antigen-binding fragment thereof that "specifically binds" to a target (e.g., an epitope) or "specific binding" to a target is a term well known in the art, and methods for determining such specific binding are also well known in the art. A molecule is said to exhibit "specific binding" when it reacts or associates with a particular cell or substance more frequently, more rapidly, for a longer duration, and / or with higher affinity than with other cells or substances. An antibody "specifically binds" to a target when it binds to the target with higher affinity, avidity, more readily, and / or for a longer duration than with other substances. For example, an antibody that specifically binds to a LILRB2 epitope is an antibody that binds to this LILRB2 epitope with higher affinity, avidity, more readily, and / or for a longer duration than to other LILRB2 epitopes or non-LILRB2 epitopes. Reading this definition also understands, for example, that an antibody (or moiety or epitope) that specifically binds to a first target may or may not specifically bind to a second target. Thus, "specific binding" or "specifically binds" does not necessarily require (although it can include) exclusive binding. Generally, but not necessarily, reference to binding means specific binding.

[0082] As used herein, the ability to "compete for binding to LILRB2" refers to the ability of a first antibody or antigen-binding fragment to inhibit, to any detectable extent, the binding interaction between LILRB2 and a second anti-LILRB2 antibody. In certain embodiments, an antibody or antigen-binding fragment that competes for binding to LILRB2 inhibits the binding interaction between LILRB2 and a second anti-LILRB2 antibody by at least 85%, or at least 90%. In certain embodiments, this inhibition may be greater than 95%, or greater than 99%.

[0083] The term "epitope," as used herein, refers to a specific group of atoms or amino acids on an antigen that binds to an antibody. Two antibodies may bind to the same or closely related epitopes within an antigen if they exhibit competitive binding to the antigen. The epitope may be a linear epitope or a conformational epitope (i.e., involving separate amino acid residues). For example, an antibody or antigen-binding fragment and a reference antibody may be considered to bind to the same epitope / closely related epitopes if the antibody or antigen-binding fragment blocks the binding of the reference antibody to the antigen by at least 85%, or at least 90%, or at least 95%.

[0084] The term "amino acid," as used herein, refers to an organic compound containing an amine (-NH) and a carboxyl (-COOH) functional group, as well as a side chain unique to each amino acid. The names of amino acids are also represented in this disclosure as standard one-letter or three-letter codes and are summarized as follows:

[0085] [Table 1]

[0086] With respect to amino acid sequences, a "conservative substitution" refers to the replacement of an amino acid residue with another amino acid residue having a side chain with similar physicochemical properties. For example, conservative substitutions can be made between amino acid residues having hydrophobic side chains (e.g., Met, Ala, Val, Leu, and Ile), neutral hydrophilic side chains (e.g., Cys, Ser, Thr, Asn, and Gln), acidic side chains (e.g., Asp, Glu), basic side chains (e.g., His, Lys, and Arg), or aromatic side chains (e.g., Trp, Tyr, and Phe). As is known in the art, conservative substitutions usually do not significantly alter the conformational structure of a protein, thereby preserving the biological activity of the protein.

[0087] The term "homologous," as used herein, refers to a nucleic acid sequence (or its complementary strand) or amino acid sequence that has at least 60% (e.g., at least 65%, 70%, 75%, 80%, 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) sequence identity with another sequence when optimally aligned.

[0088] "Percent (%) sequence identity" with respect to an amino acid sequence (or nucleic acid sequence) is defined as the percentage of amino acid (or nucleic acid) residues in a candidate sequence that are identical to the amino acid (or nucleic acid) residues in a reference sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum number of identical amino acids (or nucleic acids). In other words, the percent (%) sequence identity of an amino acid sequence (or nucleic acid sequence) can be calculated by dividing the number of identical amino acid residues (or bases) with respect to the reference sequence being compared by the total number of amino acid residues (or bases) in either the candidate sequence or the reference sequence, whichever is shorter. Conservative substitutions of amino acid residues may or may not be considered identical residues. Alignment for purposes of determining percent amino acid (or nucleic acid) sequence identity can be accomplished by publicly available tools such as, for example, BLASTN, BLASTp (available at the National Center for Biotechnology Information (NCBI) website; see also Altschul SF et al., J. Mol. Biol., 215:403-410 (1990); Stephen F. et al., Nucleic Acids Res., 25:3389-3402 (1997)), ClustalW2 (available at the European Bioinformatics Institute website; see also Higgins DG et al., Methods in Enzymology, 266:383-402 (1996); Larkin MA et al., Bioinformatics (Oxford, England), 23(21): 2947-8 (2007)), and ALIGN or Megalign (DNASTAR) software. Those skilled in the art can use the default parameters provided by these tools or customize the parameters for alignment, for example, by selecting a suitable algorithm.

[0089] As used herein, "effector function" refers to a biological activity resulting from the binding of the Fc region of an antibody to an effector such as the C1 complex and an Fc receptor. Exemplary effector functions include complement-dependent cytotoxicity (CDC), which is mediated by the interaction of an antibody on the C1 complex with C1q, antibody-dependent cellular cytotoxicity (ADCC), which is mediated by the binding of the Fc region of an antibody to an Fc receptor on an effector cell, and phagocytosis. Effector function can be assessed by various assays, such as Fc receptor binding assays, C1q binding assays, and cytolytic assays.

[0090] "Functional blocking," as used herein, refers to the mechanism by which an antibody or antigen-binding fragment thereof can bind to a protein and prevent the protein from binding to another ligand, thereby modulating downstream signaling activity.

[0091] "Antibody-dependent cellular cytotoxicity" or "ADCC," as used herein, refers to a cell-mediated reaction in which effector cells expressing Fc receptors (FcRs) recognize bound antibodies or antigen-binding fragments on target cells, subsequently causing lysis of the target cells. "ADCC activity" or "ADCC effect" refers to the ability of an antibody or antigen-binding fragment bound to a target cell to cause the ADCC reaction described above.

[0092] "Complement-dependent cytotoxicity" or "CDC," as used herein, refers to the mechanism by which antibodies can mediate the lysis of specific target cells through activation of an organism's complement system. In CDC, C1q binds to antibodies, and this binding triggers the complement cascade, which leads to the formation of the membrane attack complex (MAC) (C5b-C9) on the surface of target cells, as a result of classical pathway complement activation. "CDC activity" or "CDC effect" refers to the ability of an antibody or antigen-binding fragment bound to a target cell to elicit the CDC response described above.

[0093] "Effector cells" are leukocytes that express one or more Fc receptors and perform effector function. Examples of human leukocytes that mediate phagocytosis include peripheral blood mononuclear cells (PBMCs), natural killer (NK) cells, monocytes, cytotoxic T cells, and neutrophils, with PBMC-derived anti-inflammatory macrophages being preferred. Effector cells may be isolated from natural sources, such as blood or PBMCs, as known in the art.

[0094] An "isolated" material has been altered by artifical means from its natural state. When an "isolated" composition or material occurs in nature, it has been changed or removed from its original environment, or both. For example, a polynucleotide or polypeptide that naturally occurs in a living animal is not "isolated," but the same polynucleotide or polypeptide would be "isolated" if it were sufficiently separated from the coexisting materials of its natural state so that it exists in a substantially pure state. An "isolated nucleic acid sequence" refers to the sequence of an isolated nucleic acid molecule. In certain embodiments, an "isolated antibody or antigen-binding fragment thereof" refers to an antibody or antigen-binding fragment thereof that is at least 60%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% pure as measured by electrophoretic methods (such as SDS-PAGE, isoelectric focusing, capillary electrophoresis) or chromatographic methods (such as ion exchange chromatography or reverse-phase HPLC).

[0095] As used herein, the term "vector" refers to a vehicle into which a polynucleotide encoding a protein can be operably inserted to express that protein. A vector can be used to transform, transduce, or transfect a host cell to express the genetic elements carried by the vector within the host cell. Examples of vectors include plasmids, phagemids, cosmids, artificial chromosomes such as yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs), or P1-derived artificial chromosomes (PACs), bacteriophages such as lambda phage or M13 phage, and animal viruses. Categories of animal viruses used as vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpesviruses (e.g., herpes simplex viruses), poxviruses, baculoviruses, papillomaviruses, and papovaviruses (e.g., SV40). Vectors can contain various elements for controlling expression, such as promoter sequences, transcription initiation sequences, enhancer sequences, selectable elements, and reporter genes. In addition, the vector may contain an origin of replication. The vector may also contain materials that aid in entry into a cell, including, but not limited to, a viral particle, a liposome, or a protein coating. The vector may be an expression vector or a cloning vector. The present disclosure provides a vector (e.g., an expression vector) containing a nucleic acid sequence provided herein encoding an antibody or antigen-binding fragment thereof, at least one promoter (e.g., SV40, CMV, EF-1α) operably linked to the nucleic acid sequence, and at least one selectable marker.Examples of vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex virus), poxviruses, baculoviruses, papilloma viruses, papova viruses (e.g., SV40), lambda phage, and M13 phage, as well as the plasmids pcDNA3.3, pMD18-T, pOptivec, pCMV, pEGFP, pIRES, pQD-Hyg-GSeu, pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX, pGEX, and pC Examples of such vectors include, but are not limited to, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS10, pLexA, pACT2.2, pCMV-SCRIPT.RTM., pCDM8, pCDNA1.1 / amp, pcDNA3.1, pRc / RSV, PCR2.1, pEF-1, pFB, pSG5, pXT1, pCDEF3, pSVSPORT, and pEF-Bos.

[0096] The term "host cell," as used herein, refers to a cell into which an exogenous polynucleotide and / or vector can be or has been introduced.

[0097] The term "subject" includes human and non-human animals. Non-human animals include all vertebrates, e.g., mammals and non-human mammals, such as non-human primates, mice, rats, cats, rabbits, sheep, dogs, cows, chickens, amphibians, and reptiles. Unless otherwise specified, the terms "patient," "subject," or "individual" are used interchangeably herein.

[0098] The term "anti-tumor activity" refers to reducing tumor cell proliferation, viability, or metastatic activity. For example, anti-tumor activity can be demonstrated by a reduction in the rate of growth of abnormal cells or a stabilization or reduction in tumor size during treatment, or an increase in survival time with treatment, compared to a no-treatment control. Such activity can be assessed using recognized in vitro or in vivo tumor models, including, but not limited to, xenograft models, allograft models, mouse mammary tumor virus (MMTV) models, and other models known in the art for determining anti-tumor activity.

[0099] "Treating" a disease, disorder or condition, as used herein, includes preventing or alleviating the disease, disorder or condition, delaying the onset or rate of progression of the disease, disorder or condition, reducing the risk of developing the disease, disorder or condition, preventing or delaying the onset of symptoms associated with the disease, disorder or condition, reducing or terminating symptoms associated with the disease, disorder or condition, causing complete or partial regression of the disease, disorder or condition, curing the disease, disorder or condition, or some combination thereof.

[0100] The terms "diagnosis", "diagnose" and "diagnosing" refer to the identification of a pathological state, disease or condition, such as the identification of a LILRB2-related disease, or the identification of a subject having a LILRB2-related disease that may benefit from a particular treatment regimen. In some embodiments, diagnosis includes the identification of an abnormal amount or activity of LILRB2. In some embodiments, diagnosis refers to the identification of cancer in a subject.

[0101] As used herein, the term "biological sample" or "sample" refers to a biological composition collected or derived from a subject of interest that contains cellular and / or other molecular entities that can be characterized and / or identified based on, for example, physical, biochemical, chemical, and / or physiological properties. Biological samples include, but are not limited to, cells, tissues, organs, and / or biological fluids of a subject collected by any method known to those of skill in the art. In some embodiments, the biological sample is a bodily fluid sample. In some embodiments, the bodily fluid sample is whole blood, plasma, serum, mucus (including nasal secretions and sputum), peritoneal fluid, pleural fluid, saliva, urine, synovial fluid, cerebrospinal fluid (CSF), thoracentesis fluid, intraperitoneal fluid, ascites, or pericardial fluid. In some embodiments, the biological sample is tissue or cells obtained from the stomach, heart, liver, spleen, lungs, kidneys, skin, or blood vessels of a subject.

[0102] The term "LILRB2," as used herein, refers to leukocyte immunoglobulin-like receptor subfamily B member 2, and includes any variants, conformations, isoforms, and species homologs of LILRB2 naturally expressed by cells or expressed by cells transfected with the LILRB2 gene. For example, LILRB2 as described herein can refer to leukocyte immunoglobulin-like receptor subfamily B member 2 protein derived from any vertebrate source, such as primates (e.g., humans, monkeys) and rodents (e.g., mice and rats). An exemplary sequence of human LILRB2 protein is described, for example, in UniProtKB Entry No. Q8N423 or GenBank Accession No. NP_001074447.2. The term "LILRB2," as used herein, is intended to encompass any form of LILRB2, for example, 1) a native, unprocessed LILRB2 molecule, a "full-length" LILRB2 chain, or a naturally occurring variant of LILRB2, such as a splice variant or allelic variant; 2) any form of LILRB2 that results from processing within a cell; or 3) a full-length, fragment (e.g., truncated, extracellular / transmembrane domain), or modified form (e.g., mutant form, glycosylated / PEGylated, His-tag / immunofluorescence fusion form) of a LILRB2 subunit produced by recombinant methods.

[0103] The term "anti-LILRB2 antibody" or "LILRB2 antibody" refers to an antibody that binds to LILRB2 (e.g., human LILRB2) and may also bind to other targets, such as LILRB1. The term "anti-human LILRB2 antibody" or "anti-hLILRB2 antibody" refers to an antibody that binds to human LILRB2.

[0104] As used herein, a "LILRB2-related" disease, disorder, or condition refers to any disease, disorder, or condition that is caused, exacerbated, or results from increased or decreased expression or activity of LILRB2. In some embodiments, the LILRB2-related disease, disorder, or condition is a disorder associated with excessive cell proliferation, e.g., cancer. In certain embodiments, the LILRB2-related disease or condition is characterized by expression or overexpression of LILRB2 and / or LILRB2-related genes.

[0105] The term "pharmaceutically acceptable" indicates that the specified carrier, vehicle, diluent, excipient, and / or salt is generally chemically and / or physiologically compatible with the other ingredients that make up the formulation and physiologically compatible with the subject to which it is to be administered.

[0106] The term "LILRB2-expressing cells," as used herein, refers to cells that express LILRB2 on their surface. Anti-LILRB2 antibody

[0107] The present disclosure provides anti-LILRB2 antibodies and antigen-binding fragments thereof. The anti-LILRB2 antibodies and antigen-binding fragments provided herein are capable of binding (e.g., specifically binding) to LILRB2 (e.g., human LILRB2).

[0108] The binding affinity of the antibodies or antigen-binding fragments thereof provided herein is determined by the ratio of the association rate to the dissociation rate when the binding between the antigen and the antigen-binding molecule reaches equilibrium (k off / k on ) represents K D The antigen-binding affinity (e.g., K D) can be suitably determined by any suitable method known in the art, for example, a flow cytometry assay. In some embodiments, the binding of an antibody or antigen-binding fragment thereof to an antigen at different concentrations can be determined by flow cytometry, where the determined mean fluorescence intensity (MFI) is first plotted against the antibody concentration, and then the dependence of specific binding fluorescence intensity (Y) on antibody concentration (X) is calculated using Prism version 5 (GraphPad Software, San Diego, CA) using the one-site saturation equation Y = B max *X / (K D +X), K D The value can be calculated where B max refers to the maximum specific binding of the test antibody to the antigen.

[0109] The binding of the antibodies or antigen-binding fragments thereof provided herein to LILRB2 is measured using the "half maximal effective concentration" (EC), which refers to the concentration at which 50% of the maximal binding of the antibody is observed. 50 ) value. 50 Values ​​can be measured by binding assays known in the art, for example, direct or indirect binding assays such as enzyme-linked immunosorbent assays (ELISAs), FACS assays, and other binding assays.

[0110] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein can specifically bind to human LILRB2, e.g., as measured by a FACS assay. For example, the antibodies or antigen-binding fragments thereof provided herein have an EC of 10 nM or less (e.g., 9 nM or less, 8 nM or less, 7 nM or less, 6 nM or less, 5 nM or less, 4 nM or less, 3 nM or less, 2 nM or less, 1 nM or less, 0.9 nM or less, 0.8 nM or less, 0.7 nM or less, 0.6 nM or less, 0.5 nM or less, 0.4 nM or less, 0.3 nM or less, 0.2 nM or less, or 0.1 nM or less) as measured by a FACS assay. 50 It binds to human LILRB2.

[0111] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of binding to human LILRB2 and human LILRB1, as measured, for example, by a FACS assay. In the present disclosure, antibodies capable of binding to both LILRB2 and LILRB1 are also referred to as "anti-LILRB2 / 1" antibodies.

[0112] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have an EC of 15 nM or less (e.g., 10 nM or less, 9 nM or less, 8 nM or less, 7 nM or less, 6 nM or less, 5 nM or less, 4 nM or less, 3 nM or less, 2 nM or less, 1 nM or less, 0.9 nM or less, 0.8 nM or less, 0.7 nM or less, 0.6 nM or less, 0.5 nM or less, 0.4 nM or less, 0.3 nM or less, 0.2 nM or less, or 0.1 nM or less) as measured by FACS assay. 50 and binds to human LILRB1 at an EC of 15 nM or less (e.g., 10 nM or less, 9 nM or less, 8 nM or less, 7 nM or less, 6 nM or less, 5 nM or less, 4 nM or less, 3 nM or less, 2 nM or less, 1 nM or less, 0.9 nM or less, 0.8 nM or less, 0.7 nM or less, 0.6 nM or less, 0.5 nM or less, 0.4 nM or less, 0.3 nM or less, 0.2 nM or less, or 0.1 nM or less) as measured by FACS assay. 50 It binds to human LILRB2.

[0113] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of binding to human LILRB2 and rhesus monkey LILRB2, e.g., as measured by a FACS assay. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are cross-reactive with human and rhesus monkey LILRB2, e.g., as measured by a FACS assay.

[0114] The term "cross-reactivity" or "cross-reactive," as used herein, refers to the ability of a binding protein to bind to a target other than its target. Generally, a binding protein binds to its target tissue / antigen with appropriately high affinity, while exhibiting appropriately low affinity for non-target normal tissue / antigen. Individual binding proteins are generally selected to meet the following two criteria: (1) the antibody binds to tissue appropriate for known expression of the antibody target, as visualized by staining methods known in the art; and (2) tissues from the same organ have similar staining patterns between humans and toxin species (e.g., mice and cynomolgus monkeys). These and other methods for assessing cross-reactivity are known to those skilled in the art (e.g., US20090311253A1).

[0115] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of functionally blocking the interaction of LILRB2 with its ligand. In certain embodiments, the ligand is HLA-G. In certain embodiments, the blocking effect is measured using a chimeric receptor reporter system as described in Example 3 of the present disclosure.

[0116] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of enhancing polarization of macrophages toward a more inflammatory phenotype. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein enhance the inflammatory response in immature macrophages, as measured, for example, by detecting TNF-α secretion and / or CD86 expression, as described in Example 4 of the present disclosure. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein suppress M2-like polarization of immature macrophages to rescue T cell activation, as measured, for example, by detecting CD25 expression, as described in Example 4 of the present disclosure.

[0117] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of enhancing anti-CD47-mediated phagocytosis. The phagocytic effect can be measured by any method known in the art. For example, the phagocytic effect can be measured by the method described in Example 5 of the present disclosure. In certain embodiments, in the phagocytic effect assay, the target cells are human melanoma cancer cells A375 stably expressing HLA-G (A375-HLA-G), and the effector cells are anti-inflammatory macrophages derived from PBMCs.

[0118] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein can enhance T cell or myeloid cell inflammatory cytokine secretion (e.g., GM-CSF secretion and / or TNF-α secretion). For example, the effect of anti-LILRB2 antibodies of the present disclosure on myeloid-derived cytokine secretion can be measured by the methods described in Example 4.2 of the present disclosure.

[0119] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of inhibiting the polarization of monocytes toward a macrophage-like immunosuppressive phenotype. For example, the inhibitory effect of anti-LILRB2 antibodies of the present disclosure on the polarization of monocytes toward a macrophage-like immunosuppressive phenotype can be measured by the method described in Example 4.3 of the present disclosure.

[0120] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of reversing MDSC-mediated suppression of T cell activation. For example, the reversal effect of an anti-LILRB2 antibody of the present disclosure on MDSC-mediated suppression of T cell activation can be measured by the method described in Example 4.5 of the present disclosure.

[0121] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are capable of rescuing T cell activity from suppression by immunosuppressive myeloid cells when used in combination with an anti-PD-1 or anti-PD-L1 agent. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein rescue T cell activity from suppression by immunosuppressive myeloid cells, as measured, for example, by determining IFN-γ production as described in Example 6 of the present disclosure. Exemplary Anti-LILRB2 Antibodies

[0122] In certain embodiments, the present disclosure provides an antibody or antigen-binding fragment thereof that binds to LILRB2, one, two or three heavy chain complementarity determining regions (HCDR1, HCDR2 and / or HCDR3) contained within any one of the heavy chain variable (VH) region sequences selected from the group consisting of SEQ ID NOs: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231 and 239, and / or Provided is an antibody or antigen-binding fragment thereof comprising one, two or three light chain complementarity determining regions (LCDR1, LCDR2 and / or LCDR3) contained within any one of the light chain variable (VL) region sequences selected from the group consisting of SEQ ID NOs: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232 and 240.

[0123] Those skilled in the art can define or identify the CDR boundaries of a VH or VL region by methods well known in the art, provided that the amino acid sequence of the VH or VL region is known. For example, the CDR boundaries of an antibody or antigen-binding fragment thereof may be defined or identified according to the Kabat, IMGT, Chothia, or Al-Lazikani definitions (Al-Lazikani, B., Chothia, C., Lesk, AM, J. Mol. Biol., 273(4), 927 (1997); Chothia, C. et al., J. Mol. Biol. Dec 5;186(3):651-63 (1985); Chothia, C. and Lesk, AM, J. Mol. Biol., 196,901 (1987); Chothia, C. et al., Nature. Dec 21-28;342(6252):877-83 (1989); Kabat EA et al., Sequences of Proteins of Immunological Interest, 5 thEd. Public Health Service, National Institutes of Health, Bethesda, Md. (1991); Marie-Paule Lefranc et al., Developmental and Comparative Immunology, 27: 55-77 (2003); Marie-Paule Lefranc et al., Immunome Research, 1(3), (2005); Marie-Paule Lefranc, Molecular Biology of B cells (second edition), chapter 26, 481-514, (2015)). In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are identified according to the Kabat convention. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are identified according to the IMGT convention. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are identified according to the Chothia convention. In some embodiments, the CDR boundaries of the antibodies or antigen-binding fragments thereof provided herein are identified according to the Al-Lazikani definition.

[0124] In certain embodiments, the present disclosure provides an antibody or antigen-binding fragment thereof that binds to LILRB2, including anti-LILRB2 antibodies 23-H3-D3-C7, 44-D7-C12-B6, 45-H2-B10-G4-F3, 30-D2-F6-F10, 18-D2-G7-G8, 20-H7-F3-H5, 33-E3-C9-G8, 18-H4-A10-B7, 41-E2-E6-E12-E5, 33-G2-C6-E3, 34-A5-A8-D6, 49-D6-G3-E1, 41-E2-E5-C7, 7-E10-G7-E7, 34-F6-H9-D1, 34- Provided are antibodies or antigen-binding fragments thereof comprising one or more (e.g., 1, 2, 3, 4, 5, or 6) CDR sequences of F12-G3-G12, 45-F1-F5-A2, 38-C7-D6-G3, 12-C11-G2-H5, 14-G11-G12-C4, 33-G3-C3-D8, 17-F8-G4-C5, 44-A4-B8-A4, 30-A12-C8-F8, 50-F11-G7-F8, 10-F12-G9-D3, 24-A4-G8-C11-H3, 47-E4-A8-A8, 40-G4-A8-G5, or 19-H6-A9-E4.

[0125] The antibody "23-H3-D3-C7," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 7 and a light chain variable region having the sequence of SEQ ID NO: 8.

[0126] The antibody "44-D7-C12-B6," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 15 and a light chain variable region having the sequence of SEQ ID NO: 16.

[0127] The antibody "45-H2-B10-G4-F3," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 23 and a light chain variable region having the sequence of SEQ ID NO: 24.

[0128] The antibody "30-D2-F6-F10," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 31 and a light chain variable region having the sequence of SEQ ID NO: 32.

[0129] The antibody "18-D2-G7-G8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 39 and a light chain variable region having the sequence of SEQ ID NO: 40.

[0130] The antibody "20-H7-F3-H5," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 47 and a light chain variable region having the sequence of SEQ ID NO: 48.

[0131] The antibody "33-E3-C9-G8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 55 and a light chain variable region having the sequence of SEQ ID NO: 56.

[0132] The antibody "18-H4-A10-B7," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 63 and a light chain variable region having the sequence of SEQ ID NO: 64.

[0133] The antibody "41-E2-E6-E12-E5," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 71 and a light chain variable region having the sequence of SEQ ID NO: 72.

[0134] The antibody "33-G2-C6-E3," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 79 and a light chain variable region having the sequence of SEQ ID NO: 80.

[0135] The antibody "34-A5-A8-D6," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 87 and a light chain variable region having the sequence of SEQ ID NO: 88.

[0136] The antibody "49-D6-G3-E1," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 95 and a light chain variable region having the sequence of SEQ ID NO: 96.

[0137] The antibody "41-E2-E5-C7," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 103 and a light chain variable region having the sequence of SEQ ID NO: 104.

[0138] The antibody "7-E10-G7-E7," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 111 and a light chain variable region having the sequence of SEQ ID NO: 112.

[0139] The antibody "34-F6-H9-D1," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 119 and a light chain variable region having the sequence of SEQ ID NO: 120.

[0140] The antibody "34-F12-G3-G12," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 127 and a light chain variable region having the sequence of SEQ ID NO: 128.

[0141] The antibody "45-F1-F5-A2," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 135 and a light chain variable region having the sequence of SEQ ID NO: 136.

[0142] The antibody "38-C7-D6-G3," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 143 and a light chain variable region having the sequence of SEQ ID NO: 144.

[0143] The antibody "12-C11-G2-H5," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 151 and a light chain variable region having the sequence of SEQ ID NO: 152.

[0144] The antibody "14-G11-G12-C4," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 159 and a light chain variable region having the sequence of SEQ ID NO: 160.

[0145] The antibody "33-G3-C3-D8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 167 and a light chain variable region having the sequence of SEQ ID NO: 168.

[0146] The antibody "17-F8-G4-C5," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 175 and a light chain variable region having the sequence of SEQ ID NO: 176.

[0147] The antibody "44-A4-B8-A4," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 183 and a light chain variable region having the sequence of SEQ ID NO: 184.

[0148] The antibody "30-A12-C8-F8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 191 and a light chain variable region having the sequence of SEQ ID NO: 192.

[0149] The antibody "50-F11-G7-F8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 199 and a light chain variable region having the sequence of SEQ ID NO: 200.

[0150] The antibody "10-F12-G9-D3," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 207 and a light chain variable region having the sequence of SEQ ID NO: 208.

[0151] The antibody "24-A4-G8-C11-H3," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 215 and a light chain variable region having the sequence of SEQ ID NO: 216.

[0152] The antibody "47-E4-A8-A8," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 223 and a light chain variable region having the sequence of SEQ ID NO: 224.

[0153] The antibody "40-G4-A8-G5," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 231 and a light chain variable region having the sequence of SEQ ID NO: 232.

[0154] The antibody "19-H6-A9-E4," as used herein, refers to a murine monoclonal antibody comprising a heavy chain variable region having the sequence of SEQ ID NO: 239 and a light chain variable region having the sequence of SEQ ID NO: 240.

[0155] The specific amino acid sequences of the heavy and light chain variable regions of each of the exemplary antibodies described above are shown in Table 3 below.

[0156] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 7, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 8.

[0157] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 15, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 16.

[0158] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 23, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 24.

[0159] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 31, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 32.

[0160] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 39, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 40.

[0161] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 47, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 48.

[0162] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 55, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 56.

[0163] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 63, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 64.

[0164] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 71, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 72.

[0165] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 79, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 80.

[0166] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 87, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 88.

[0167] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 95, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 96.

[0168] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 103, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 104.

[0169] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 111, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 112.

[0170] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 119, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 120.

[0171] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 127, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 128.

[0172] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 135, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 136.

[0173] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 143, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 144.

[0174] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 151, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 152.

[0175] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 159, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 160.

[0176] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 167, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 168.

[0177] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 175, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 176.

[0178] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 183, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 184.

[0179] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 191, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 192.

[0180] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 199, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 200.

[0181] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 207, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 208.

[0182] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 215, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 216.

[0183] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 223, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 224.

[0184] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 231, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 232.

[0185] In certain embodiments, the antibody or antigen-binding fragment thereof provided herein comprises three heavy chain CDRs (HCDR1, HCDR2, and HCDR3) contained within the VH region sequence set forth in SEQ ID NO: 239, and three light chain CDRs (LCDR1, LCDR2, and LCDR3) contained within the VL region sequence set forth in SEQ ID NO: 240.

[0186] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 13 7, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 97, 98, 99, 100, 101, 102, 105, 106, 107, 108, 109, 110, 113, 114, 115, 116, 117, 118, 121, 122, 123, 124, 125, 126, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 1 7, 138, 139, 140, 141, 142, 145, 146, 147, 148, 149, 150, 153, 154, 155, 156, 157, 158, 161, 162, 163, 164, 165, 166, 169, 170, 171, 172, 173, 174, 177, 178, 179, 180, 181, 182, 185, 186, 187, 188, 189, 190, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 25 220, 221, 222, 225, 226, 227, 228, 229, 230, 233, 234, 235, 236, 237, and 238.

[0187] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 97, 98, 99, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139 , 145, 146, 147, 153, 154, 155, 161, 162, 163, 169, 170, 171, 177, 178, 179, 185, 186, 187, 193, 194, 195, 201, 202, 203, 209, 210, 211, 217, 218, 219, 225, 226, 227, 233, 234 and 235.

[0188] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NOs: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 100, 101, 102, 108, 109, 110, 116, 117, 118, 124, 125, 126, 132, 133, 134, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 220, 221, 222, 223, 2 and a VL region comprising one or two or three of LCDR1, LCDR2 and LCDR3 comprising an amino acid sequence selected from the group consisting of: 42, 148, 149, 150, 156, 157, 158, 164, 165, 166, 172, 173, 174, 180, 181, 182, 188, 189, 190, 196, 197, 198, 204, 205, 206, 212, 213, 214, 220, 221, 222, 228, 229, 230, 236, 237 and 238.

[0189] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise an HCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, 113, 121, 129, 137, 145, 153, 161, 169, 177, 185, 193, 201, 209, 217, 225, and 233; , 130, 138, 146, 154, 162, 170, 178, 186, 194, 202, 210, 218, 226 and 234, and an HCDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227 and 235.

[0190] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein comprise an LCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 100, 108, 116, 124, 132, 140, 148, 156, 164, 172, 180, 188, 196, 204, 212, 220, 228, and 236; and an LCDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 102, 110, 118, 126, 134, 142, 150, 158, 166, 174, 182, 190, 198, 206, 214, 222, 230, and 238.

[0191] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 2, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 3; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11; iii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 18, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 19; iv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27; v. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 34, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 35; vi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 42, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 43; vii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 50, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 51; viii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59; ix. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67; x. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 74, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 75; xi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91; xiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 98, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 99; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115; xvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 122, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 123; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131; xviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 138, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 139; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155; xxi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 162, and HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 163; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219; xxix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, or xxx. Comprises HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 234, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 235.

[0192] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 6; ii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 14; iii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 22; iv. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 30; v. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 38; vi. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 46; vii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 54; viii. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 62; ix. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 70; x. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 78; xi. LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 86; xii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 102; xiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 126; xvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 142; xix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 166; xxii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 238.

[0193] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein: i. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 2, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 3, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 6; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 14; iii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 18, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 19, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 22; iv. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 26, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 27, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 30; v. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 34, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 35, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 38; vi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 42, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 43, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 46; vii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 50, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 51, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 54; viii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 58, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 59, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 62; ix. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 66, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 67, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 70; x. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 74, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 75, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 78; xi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 82, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 83, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 86; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 98, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 99, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 102; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 122, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 123, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 126; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 138, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 139, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 142; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. HCDR1 comprising the amino acid sequence shown in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence shown in SEQ ID NO: 162, HCDR3 comprising the amino acid sequence shown in SEQ ID NO: 163, LCDR1 comprising the amino acid sequence shown in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence shown in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence shown in SEQ ID NO: 166; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. Comprises HCDR1 having the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 having the amino acid sequence set forth in SEQ ID NO: 234, HCDR3 having the amino acid sequence set forth in SEQ ID NO: 235, LCDR1 having the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 having the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 having the amino acid sequence set forth in SEQ ID NO: 238.

[0194] The sequence numbers of the heavy chain (referred to as "H") variable region, light chain (referred to as "L") variable region, HCDR, and LCDR for each of the 30 monoclonal antibodies described above are set forth in Table 1 below. The amino acid sequences of each CDR for the 30 exemplary monoclonal antibodies are set forth in Table 2 below. Unless otherwise indicated, the CDR boundaries set forth in Table 2 below are defined or specified according to the Kabat convention. The amino acid sequences of each VH and VL for the 30 exemplary monoclonal antibodies are set forth in Table 3 below.

[0195] [Table 2-1] [Table 2-2]

[0196] [Table 3-1] [Table 3-2] [Table 3-3] [Table 3-4]

Table 3-5

[0197]

Table 4-1

Table 4-2

Table 4-3

Table 4-4

Table 4-5

Table 4-6

Table 4-7

Table 4-8

[0198] The HCDR1, HCDR2, and HCDR3 sequences and LCDR1, LCDR2, and LCDR3 sequences of each of the 30 exemplary monoclonal antibodies can be "mixed and matched" to generate anti-LILRB2 antibodies or antigen-binding fragments thereof of the present disclosure, provided that the 30 exemplary monoclonal antibodies can bind to LILRB2 and that antigen-binding specificity is primarily provided by the CDR1, CDR2, and CDR3 regions (i.e., CDRs from different antibodies can be mixed and matched, but each antibody must contain HCDR1, HCDR2, and HCDR3 and LCDR1, LCDR2, and LCDR3). LILRB2 binding of such "mixed and matched" antibodies can be tested using the binding assays described above and in the Examples. Preferably, when VH CDR sequences are mixed and matched, the HCDR1, HCDR2, and / or HCDR3 sequences from a particular VH sequence are replaced with structurally similar CDR sequence(s). Similarly, when VL CDR sequences are mixed and matched, the LCDR1, LCDR2, and / or LCDR3 sequences from a particular VL sequence are preferably replaced with structurally similar CDR sequence(s). For example, the HCDR1s of antibodies 38-C7-D6-G3 and 12-C11-G2-H5 share certain structural similarities and can therefore be mixed and matched. It will be readily apparent to one of skill in the art that novel VH and VL sequences can be generated by replacing one or more VH and / or VL CDR sequences with structurally similar sequences from the CDR sequences of the 30 exemplary monoclonal antibodies disclosed herein.

[0199] CDRs are known to be responsible for antigen binding. However, it has been found that not all six CDRs are essential or inalterable. In other words, one or more CDRs in each of the 30 exemplary monoclonal antibodies can be replaced, altered, or modified while substantially retaining the specific binding affinity to LILRB2.

[0200] In certain embodiments, the anti-LILRB2 antibodies and antigen-binding fragments provided herein include anti-LILRB2 antibodies 23-H3-D3-C7, 44-D7-C12-B6, 45-H2-B10-G4-F3, 30-D2-F6-F10, 18-D2-G7-G8, 20-H7-F3-H5, 33-E3-C9-G8, 18-H4-A10-B7, 41-E2-E6-E12-E5, 33-G2-C6-E3, 34-A5-A8-D6, 49-D6-G3-E1, 41-E2-E5-C7, 7-E10-G7- and one of the heavy chain CDR3 sequences selected from the group consisting of E7, 34-F6-H9-D1, 34-F12-G3-G12, 45-F1-F5-A2, 38-C7-D6-G3, 12-C11-G2-H5, 14-G11-G12-C4, 33-G3-C3-D8, 17-F8-G4-C5, 44-A4-B8-A4, 30-A12-C8-F8, 50-F11-G7-F8, 10-F12-G9-D3, 24-A4-G8-C11-H3, 47-E4-A8-A8, 40-G4-A8-G5, and 19-H6-A9-E4. In certain embodiments, the anti-LILRB2 antibodies and antigen-binding fragments thereof provided herein comprise a heavy chain CDR3 sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227, and 235. The heavy chain CDR3 region is located in the center of the antigen-binding site and is therefore thought to make the most contacts with the antigen and contribute the most free energy to the affinity of the antibody to the antigen. The heavy chain CDR3 is also thought to be the most diverse of the CDRs in the antigen-binding site in terms of length, amino acid composition, and conformation due to multiple diversification mechanisms (Tonegawa S. Nature. 302:575-81). Diversity of the heavy chain CDR3 is sufficient to generate most antibody characteristics (Xu JL, Davis MM. Immunity. 13:37-45) and desirable antigen-binding affinities (Schier R, et al., J Mol Biol. 263:551-67).

[0201] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have an amino acid sequence set forth in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, or 239, or a sequence set forth in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, or 239. 1, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, or 239, having a homologous sequence thereof that has at least 80% (e.g., 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%, or at least 99%) sequence identity thereto.

[0202] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have an amino acid sequence set forth in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, or 240, or a sequence set forth in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, or 240. 2, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, or 240, having a homologous sequence thereof that has at least 80% (e.g., 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%, or at least 99%) sequence identity to the VL region of the VL region.

[0203] In certain embodiments, an antibody or antigen-binding fragment thereof provided herein comprises a VH / VL amino acid sequence pair selected from the group consisting of SEQ ID NOs: 7 / 8, 15 / 16, 23 / 24, 31 / 32, 39 / 40, 47 / 48, 55 / 56, 63 / 64, 71 / 72, 79 / 80, 87 / 88, 95 / 96, 103 / 104, 111 / 112, 119 / 120, 127 / 128, 135 / 136, 143 / 144, 151 / 152, 159 / 160, 167 / 168, 175 / 176, 183 / 184, 191 / 192, 199 / 200, 207 / 208, 215 / 216, 223 / 224, 231 / 232, and 239 / 240.

[0204] In certain embodiments, the antibodies and antigen-binding fragments thereof provided herein comprise suitable framework region (FR) sequences, so long as the antibodies and antigen-binding fragments thereof are capable of binding to LILRB2. The CDR sequences provided in Table 2 above are obtained from mouse antibodies, but can be grafted to suitable FR sequences of any suitable species, such as mouse, human, rat, rabbit, etc., by suitable methods known in the art, such as recombinant techniques.

[0205] In certain embodiments, the antibodies and antigen-binding fragments thereof provided herein are humanized. Humanized antibodies or antigen-binding fragments thereof are desirable due to their reduced immunogenicity in humans. Humanized antibodies have chimeric variable regions in which non-human CDR sequences are grafted onto human or substantially human FR sequences. Humanization of antibodies or antigen-binding fragments can essentially be achieved by substituting non-human (e.g., murine) CDR genes for the corresponding human CDR genes in a human immunoglobulin gene (see, e.g., Jones et al., (1986) Nature 321:522-525; Riechmann et al., (1988) Nature 332:323-327; Verhoeyen et al., (1988) Science 239:1534-1536).

[0206] Suitable human heavy and light chain variable domains may be selected to this end by methods known in the art. In an illustrative example, a "best-fit" approach may be used, in which a non-human (e.g., rodent) antibody variable domain sequence is screened or BLASTed against a database of known human variable domain sequences, and the human sequence closest to the non-human query sequence is identified and used as a human scaffold for grafting the non-human CDR sequences (see, e.g., Sims et al., (1993) J. Immunol. 151:2296; Chothia et al., (1987) J. Mot. Biol. 196:901). Alternatively, frameworks derived from the consensus sequence of all human antibodies may be used for grafting non-human CDRs (see, e.g., Carter et al., (1992) Proc. Natl. Acad. Sci. USA, 89:4285; Presta et al., (1993) J. Immunol., 151:2623).

[0207] In some embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein are humanized. In certain embodiments, the humanized antibodies or antigen-binding fragments thereof provided herein are composed of substantially all human sequences, excluding non-human CDR sequences. In some embodiments, the variable region FRs and constant region (if present) are derived entirely or substantially from human immunoglobulin sequences. The human FR sequences and human constant region sequences may be derived from different human immunoglobulin genes, e.g., the FR sequences are derived from one human antibody and the constant region is derived from another human antibody. In some embodiments, the humanized antibodies or antigen-binding fragments thereof comprise human heavy chains HFR1, HFR2, HFR3, and HFR4, and / or light chains LFR1, LFR2, LFR3, and LFR4.

[0208] In some embodiments, the FR region derived from a human may comprise the same amino acid sequence as the human immunoglobulin from which it was derived. In some embodiments, one or more amino acid residues in the human FR are substituted with the corresponding residue from the parent non-human antibody. In certain embodiments, this may be desirable to bring the humanized antibody or fragment thereof closer to the non-human parent antibody structure and optimize binding characteristics (e.g., increase binding affinity). In certain embodiments, the humanized antibody or antigen-binding fragment thereof provided herein contains no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residue substitutions in each of the human FR sequences, or no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residue substitutions in all of the FR sequences of the heavy or light chain variable domain. In some embodiments, such changes in amino acid residues may occur only in the heavy chain FR region, only in the light chain FR region, or in both chains. In certain embodiments, one or more amino acids in the human FR sequence are randomly mutated to increase binding affinity. In certain embodiments, one or more amino acids of the human FR sequence are backmutated to the corresponding amino acid of the parent non-human antibody to increase binding affinity.

[0209] In some embodiments, the anti-LILRB2 antibodies and antigen-binding fragments thereof provided herein comprise all or a portion of a heavy chain variable domain and / or all or a portion of a light chain variable domain. In one embodiment, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein are single-domain antibodies consisting of all or a portion of a heavy chain variable domain provided herein. Further information on such single-domain antibodies is available in the art (see, e.g., U.S. Patent No. 6,248,516).

[0210] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein further comprise an Fc region. In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein further comprise a human immunoglobulin (Ig) Fc region. In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein further comprise a constant region, optionally including a heavy chain and / or light chain constant region. In certain embodiments, the heavy chain constant region comprises a CH1, hinge, and / or CH2-CH3 region (or optionally a CH2-CH3-CH4 region). In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise a heavy chain constant region of human IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, or IgM. In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise a lambda (λ) light chain or a kappa (κ) light chain. The constant regions of the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein may be identical to the wild-type constant region sequence or may differ by one or more mutations. In some embodiments, the heavy chain constant region of the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprises the amino acid sequence set forth in SEQ ID NO: 281. In some embodiments, the light chain constant region of the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprises the amino acid sequence set forth in SEQ ID NO: 282. ASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK (SEQ ID NO: 281) RTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 282)

[0211] In certain embodiments, the heavy chain constant region comprises an Fc region. The Fc region is known to mediate effector functions of antibodies, such as antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). The Fc regions of different Ig isotypes have different abilities to induce effector functions. For example, it is recognized that the Fc regions of IgG1 and IgG3 induce both ADCC and CDC more effectively than IgG2 and IgG4. In certain embodiments, the anti-LILRB2 antibodies and antigen-binding fragments thereof provided herein comprise an Fc region of an IgG1 or IgG3 isotype capable of inducing ADCC or CDC, or a constant region of an IgG4 or IgG2 isotype with reduced or depleted effector function. In some embodiments, the Fc region is derived from human IgG1 with enhanced effector function. In some embodiments, the Fc region is derived from human IgG4. In some embodiments, the Fc region comprises the amino acid sequence set forth in SEQ ID NO: 283. APEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLSLGK (SEQ ID NO: 283)

[0212] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein have specific binding affinity to human LILRB2 sufficient for diagnostic and / or therapeutic uses.

[0213] The antibodies or antigen-binding fragments thereof provided herein can be monoclonal, polyclonal, humanized, human, chimeric, recombinant, bispecific, multispecific, labeled, bivalent, anti-idiotypic, or fusion proteins. Recombinant antibodies are antibodies prepared in vitro by recombinant methods and not in an animal.

[0214] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that compete with the antibodies or antigen-binding fragments thereof provided herein for binding to LILRB2. In certain embodiments, the present disclosure provides antibodies 23-H3-D3-C7, 44-D7-C12-B6, 45-H2-B10-G4-F3, 30-D2-F6-F10, 18-D2-G7-G8, 20-H7-F3-H5, 33-E3-C9-G8, 18-H4-A10-B7, 41-E2-E6-E12-E5, 33-G2-C6-E3, 34-A5-A8-D6, 49-D6-G3-E1, 41-E2-E5-C7, 7-E10-G7-E7, 34-F6-H9-D1 ... and 19-H6-A9-E4. In some embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that compete with the antibodies or antigen-binding fragments thereof provided herein for binding to LILRB2. In some embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that compete with the antibodies or antigen-binding fragments thereof provided herein for binding to the same epitope.

[0215] The ability to "block binding" or "compete for binding," as used herein, refers to the ability of an antibody or antigen-binding fragment to inhibit the binding interaction between two molecules (e.g., human LILRB2 and an anti-LILRB2 antibody) to any detectable degree. In certain embodiments, the antibody or antigen-binding fragment thereof blocks the binding between the two molecules, inhibiting the interaction between the two molecules by at least 85%, or at least 90%. In certain embodiments, this inhibition may be greater than 85%, or greater than 90%.

[0216] Those of skill in the art will be able to determine without undue experimentation whether a human monoclonal antibody is compatible with the antibodies of the disclosure (e.g., murine monoclonal antibodies 23-H3-D3-C7, 44-D7-C12-B6, 45-H2-B10-G4-F3, 30-D2-F6-F10, 18-D2-G7-G8, 20-H7-F3-H5, 33-E3-C9-G8, 18-H4-A10-B7, 41-E2-E6-E12-E5, 33-G2-C6-E3, 34-A5-A8-D6, 49-D6-G3-E1, 41-E2-E5-C7, 7-E10-G7-E7, 34-F6-H9-D1, 34-F12-G3-G12, 45-F It will be appreciated that it is possible to determine whether a specific antibody (e.g., 1-F5-A2, 38-C7-D6-G3, 12-C11-G2-H5, 14-G11-G12-C4, 33-G3-C3-D8, 17-F8-G4-C5, 44-A4-B8-A4, 30-A12-C8-F8, 50-F11-G7-F8, 10-F12-G9-D3, 24-A4-G8-C11-H3, 47-E4-A8-A8, 40-G4-A8-G5 or 19-H6-A9-E4) binds to the same epitope as a specific antibody (e.g., 1-F5-A2, 38-C7-D6-G3, 12-C11-G2-H5, 14-G11-G12-C4, 33-G3-C3-D8, 17-F8-G4-C5, 44-A4-B8-A4, 30-A12-C8-F8, 50-F11-G7-F8, 10-F12-G9-D3, 24-A4-G8-C11-H3, 47-E4-A8-A8, 40-G4-A8-G5 or 19-H6-A9-E4) by determining whether the former blocks the latter from binding to the LILRB2 antigen polypeptide. If the test antibody competes with an antibody of the present disclosure, as indicated by decreased binding of the antibody of the present disclosure to the LILRB2 antigen polypeptide, then the two antibodies bind to the same epitope, or closely related epitopes. Alternatively, if the binding of the test antibody to the LILRB2 antigen polypeptide is inhibited by the antibody of the present disclosure, then the two antibodies bind to the same epitope, or closely related epitopes.

[0217] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that have higher, lower, or equivalent binding affinity to LILRB2 (e.g., human LILRB2) compared to antibody J-19.h1. Information about antibody J-19.h1 is described, for example, in US20190194327A1.

[0218] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that have higher, lower, or equivalent binding affinity to LILRB2 (e.g., human LILRB2) compared to antibody 1E1. Information about antibody 1E1 is described, for example, in US20180298096A1.

[0219] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that have higher, lower, or equivalent binding affinity to LILRB1 (e.g., human LILRB1) compared to antibody Hz73D1.v1. Information about antibody Hz73D1.v1 is described, for example, in WO2021222544A1.

[0220] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that have higher, lower, or equivalent binding affinity to LILRB1 (e.g., human LILRB1) compared to antibody 15G8. Information about antibody 15G8 is described, for example, in WO2021028921A1.

[0221] In certain embodiments, the present disclosure provides anti-LILRB2 antibodies or antigen-binding fragments thereof that have higher, lower, or equivalent binding affinity to LILRB2 (e.g., human LILRB2) compared to antibody B2-19. Information about antibody B2-19 is described, for example, in WO2021158413A1.

[0222] As used herein, "J-19.h1" refers to an antibody or antigen-binding fragment thereof comprising one, two, or three heavy chain CDRs contained within a heavy chain variable region having the amino acid sequence of SEQ ID NO: 247 and one, two, or three light chain CDRs contained within a light chain variable region having the amino acid sequence of SEQ ID NO: 248. In a specific embodiment, J-19.h1 comprises an HCDR1 comprising the amino acid sequence of SEQ ID NO: 241, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 242, an HCDR3 comprising the amino acid sequence of SEQ ID NO: 243, an LCDR1 comprising the amino acid sequence of SEQ ID NO: 244, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 245, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 246. The amino acid sequences of each CDR, VH region, and VL region of J-19.h1 are set forth in Table 4 below. The CDR boundaries of J-19.h1 in Table 4 below are defined according to the Kabat rules.

[0223] As used herein, "1E1" refers to an antibody or antigen-binding fragment thereof comprising one, two, or three heavy chain CDRs contained within a heavy chain variable region having the amino acid sequence of SEQ ID NO: 255, and one, two, or three light chain CDRs contained within a light chain variable region having the amino acid sequence of SEQ ID NO: 256. In a specific embodiment, 1E1 comprises an HCDR1 comprising the amino acid sequence of SEQ ID NO: 249, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 250, an HCDR3 comprising the amino acid sequence of SEQ ID NO: 251, an LCDR1 comprising the amino acid sequence of SEQ ID NO: 252, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 253, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 254. The amino acid sequences of each CDR, VH region, and VL region of 1E1 are set forth in Table 4 below.

[0224] As used herein, "Hz73D1.v1" refers to an antibody or antigen-binding fragment thereof comprising one, two, or three heavy chain CDRs contained within a heavy chain variable region having the amino acid sequence of SEQ ID NO: 263, and one, two, or three light chain CDRs contained within a light chain variable region having the amino acid sequence of SEQ ID NO: 264. In a specific embodiment, Hz73D1.v1 comprises an HCDR1 comprising the amino acid sequence of SEQ ID NO: 257, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 258, an HCDR3 comprising the amino acid sequence of SEQ ID NO: 259, an LCDR1 comprising the amino acid sequence of SEQ ID NO: 260, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 261, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 262. The amino acid sequences of each CDR, VH region, and VL region of Hz73D1.v1 are set forth in Table 4 below. The CDR boundaries of Hz73D1.v1 in Table 4 below are defined according to the Kabat rules.

[0225] As used herein, "15G8" refers to an antibody or antigen-binding fragment thereof comprising one, two, or three heavy chain CDRs contained within a heavy chain variable region having the amino acid sequence of SEQ ID NO: 271 and one, two, or three light chain CDRs contained within a light chain variable region having the amino acid sequence of SEQ ID NO: 272. In a specific embodiment, 15G8 comprises an HCDR1 comprising the amino acid sequence of SEQ ID NO: 265, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 266, an HCDR3 comprising the amino acid sequence of SEQ ID NO: 267, an LCDR1 comprising the amino acid sequence of SEQ ID NO: 268, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 269, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 270. The amino acid sequences of each CDR, VH region, and VL region of 15G8 are set forth in Table 4 below. The CDR boundaries of 15G8 in Table 4 below are defined according to the Kabat rules.

[0226] As used herein, "B2-19" refers to an antibody or antigen-binding fragment thereof comprising one, two, or three heavy chain CDRs contained within a heavy chain variable region having the amino acid sequence of SEQ ID NO: 290 and one, two, or three light chain CDRs contained within a light chain variable region having the amino acid sequence of SEQ ID NO: 291. In a specific embodiment, B2-19 comprises an HCDR1 comprising the amino acid sequence of SEQ ID NO: 284, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 285, an HCDR3 comprising the amino acid sequence of SEQ ID NO: 286, an LCDR1 comprising the amino acid sequence of SEQ ID NO: 287, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 288, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 289. The amino acid sequences of each CDR, VH region, and VL region of B2-19 are set forth in Table 4 below. The CDR boundaries of B2-19 in Table 4 below are defined according to the Kabat rules.

[0227] [Table 5-1] [Table 5-2] [Table 5-3] Antibody variants

[0228] The antibodies and antigen-binding fragments thereof provided herein also encompass various variants of the antibody sequences provided herein.

[0229] In certain embodiments, antibody variants comprise one or more amino acid residue substitutions or modifications while retaining binding affinity to LILRB2. In certain embodiments, at least one of the substitutions or modifications is in one or more of the CDR sequences of the VH or VL region. In certain embodiments, at least one of the substitutions or modifications is in one or more of the non-CDR sequences of the VH or VL region. In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise one or more non-naturally occurring amino acid (NNAA) substitutions. In certain embodiments, the NNAA is conjugable.

[0230] For example, antibody variants comprise one or more of the CDR sequences provided in Table 2 above, one or more of the non-CDR sequences of the heavy chain variable region or light chain variable region provided in Table 3 above, and / or one or more amino acid residue substitutions or modifications in the constant region (e.g., Fc region). Such variants retain the binding specificity of their parent antibodies to LILRB2 but have one or more desirable properties conferred by the modification or substitution. For example, antibody variants may have improved antigen-binding affinity, improved glycosylation pattern, reduced risk of glycosylation, reduced deamination, enhanced effector function, improved FcRn receptor binding, increased pharmacokinetic half-life, pH sensitivity, and / or suitability for conjugation (e.g., one or more introduced cysteine ​​residues), etc.

[0231] The parent antibody sequence may be screened to identify suitable or preferred residues for modification or substitution by methods known in the art, such as "alanine scanning mutagenesis" (see, e.g., Cunningham and Wells (1989) Science, 244:1081-1085). Briefly, target residues (e.g., charged residues such as Arg, Asp, His, Lys, and Glu) may be identified and replaced with neutral or negatively charged amino acids (e.g., alanine or polyalanine), and the modified antibodies may be produced and screened for properties of interest. If substitutions at a particular amino acid position exhibit a functional change of interest, that position may be identified as a potential residue for modification or substitution. Potential residues may be further evaluated by substituting them with different types of residues (e.g., cysteine ​​residues, positively charged residues, etc.). Affinity variants

[0232] Affinity variants of antibodies may contain modifications or substitutions in one or more CDR sequences provided in Table 2 above, one or more FR sequences provided in Table 3 above, or heavy or light chain variable region sequences. FR sequences can be easily identified by those skilled in the art based on the CDR sequences in Table 2 above and the variable region sequences in Table 3 above, as it is well known in the art that CDR regions are sandwiched between FR regions in the variable region. Affinity variants retain the specific binding affinity to LILRB2 of the parent antibody, and thus have improved LILRB2 binding affinity over that of the parent antibody. In certain embodiments, at least one (or all) of the substitutions in the CDR sequences, FR sequences, or variable region sequences comprise conservative substitutions.

[0233] Those skilled in the art will understand that even if one or more amino acid residues are substituted in the CDR sequences provided in Table 2 above and the variable region sequences provided in Table 3 above, the resulting antibody or antigen-binding fragment may still retain its binding affinity or ability to LILRB2, and may even have improved binding affinity or ability. Various methods known in the art can be used to achieve this goal. For example, antibody variants (Fab or scFv variants) may be generated and expressed using phage display technology, and then screened for binding affinity to human LILRB2. As another example, computer software may be used to virtually simulate the binding of an antibody to human LILRB2 and identify amino acid residues on the antibody that form the binding interface. Such residues may be avoided from substitution to prevent a decrease in binding affinity, or may be targeted for substitution to provide stronger binding.

[0234] In certain embodiments, the humanized antibodies or antigen-binding fragments thereof provided herein comprise one or more amino acid residue substitutions in one or more of the CDR sequences and / or one or more of the FR sequences, hi certain embodiments, the affinity variants comprise a total of no more than 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 substitutions in the CDR and / or FR sequences.

[0235] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise one, two, or three CDR sequences that share at least 80% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) sequence identity with those listed in Table 2 above, while retaining specific binding affinity to LILRB2 similar to, or even higher than, that of the parent antibody.

[0236] In certain embodiments, an anti-LILRB2 antibody or antigen-binding fragment thereof comprises one or more variable region sequences having at least 80% (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) sequence identity to those listed in Table 3 above, while retaining specific binding affinity to LILRB2 similar to, or even higher than, that of the parent antibody. In some embodiments, a total of 1 to 10 amino acids are substituted, inserted, or deleted in the variable region sequences listed in Table 3 above. In some embodiments, the substitutions, insertions, or deletions occur in regions outside the CDRs (e.g., FRs). Glycosylation variants

[0237] The anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein also encompass glycosylation variants that can be obtained to increase or decrease the degree of glycosylation of the antibody or antigen-binding fragment thereof.

[0238] The antibodies or antigen-binding fragments thereof provided herein may contain one or more modifications that introduce or remove glycosylation sites. A glycosylation site is an amino acid residue having a side chain capable of being attached to a carbohydrate moiety (e.g., an oligosaccharide structure). Glycosylation of antibodies is typically N-linked or O-linked. N-linked refers to the attachment of the carbohydrate moiety to the side chain of an asparagine residue, such as an asparagine residue in a tripeptide sequence such as asparagine-X-serine and asparagine-X-threonine, where X is any amino acid except proline. O-linked glycosylation refers to the attachment of one of the sugars, such as N-acetylgalactosamine, galactose, or xylose, to a hydroxyamino acid, most commonly serine or threonine. Removal of native glycosylation sites can be conveniently achieved, for example, by altering the amino acid sequence so that one of the above-mentioned tripeptide sequences (for N-linked glycosylation sites) or a serine or threonine residue (for O-linked glycosylation sites) present in the sequence is substituted. Similarly, new glycosylation sites can be created by introducing such tripeptide sequences or serine or threonine residues. Cysteine ​​engineered variants

[0239] The anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein also include cysteine ​​engineered variants that contain one or more introduced free cysteine ​​amino acid residues.

[0240] A free cysteine ​​residue is one that is not part of a disulfide bridge. Cysteine ​​engineered variants are useful for conjugation at the engineered cysteine ​​site, e.g., via maleimide or haloacetyl, with, e.g., cytotoxic and / or imaging compounds, labels, or radioisotopes. Methods for engineering antibodies or antigen-binding fragments thereof to introduce free cysteine ​​residues are known in the art; see, e.g., WO2006 / 034488. Fc variants

[0241] The anti-LILRB2 antibodies and antigen-binding fragments provided herein also encompass Fc variants comprising one or more amino acid residue modifications or substitutions in the Fc region and / or hinge region.

[0242] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein contain one or more amino acid substitutions that improve pH-dependent binding to the neonatal Fc receptor (FcRn). By binding to FcRn at acidic pH, such variants can avoid lysosomal degradation and subsequently be translocated and released extracellularly, thereby extending pharmacokinetic half-life. Methods for engineering antibodies or antigen-binding fragments thereof to improve their binding affinity to FcRn are well known in the art; see, for example, Vaughn, D. et al., Structure, 6(1): 63-73, 1998; Kontermann, R. et al., Antibody Engineering, Volume 1, Chapter 27: Engineering of the Fc region for improved PK, published by Springer, 2010; Yeung, Y. et al., Cancer Research, 70: 3269-3277 (2010); and Hinton, P. et al., J. Immunology, 176:346-356 (2006).

[0243] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein contain one or more amino acid substitutions that alter ADCC. Specific amino acid residues in the CH2 domain of the Fc region may be substituted to enhance ADCC activity. Alternatively, or in addition, carbohydrate structures on the antibody may be altered to enhance ADCC activity. Methods for altering ADCC activity by antibody engineering have been described in the art, for example, Shields R L. et al., J. Biol. Chem. 2001, 276(9): 6591-604; Idusogie E E. et al., J. Immunol. 2000, 164(8): 4178-84; Steurer W. et al., J. Immunol. 1995, 155(3): 1165-74; Idusogie E E. et al., J. Immunol. 2001, 166(4): 2571-5; Lazar G A. et al., PNAS, 2006, 103(11): 4005-4010; Ryan M C. et al., Mol. Cancer Ther., 2007, 6: 3009-3018; Richards See JO,. et al., Mol Cancer Ther. 2008, 7(8): 2517-27; Shields RL et al., J. Biol. Chem, 2002, 277: 26733-26740; Shinkawa T. et al., J. Biol. Chem, 2003, 278: 3466-3473.

[0244] In certain embodiments, an anti-LILRB2 antibody or antigen-binding fragment thereof comprises one or more amino acid substitutions that alter CDC, for example, by increasing or decreasing C1q binding and / or CDC (see, e.g., WO 99 / 51642, Duncan & Winter Nature 322:738-40 (1988), U.S. Pat. No. 5,648,260, U.S. Pat. No. 5,624,821, and WO 94 / 29351 for other examples of Fc region variants). One or more amino acids selected from amino acid residues 329, 331, and 322 in the Fc region may be replaced with another amino acid residue to alter C1q binding and / or enhance CDC (see U.S. Pat. No. 6,194,551 by Idusogie et al.). One or more amino acid substitutions may also be introduced to alter the ability of the antibody to fix complement (see PCT Publication WO 94 / 29351 by Bodmer et al.).

[0245] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise one or more amino acid substitutions at positions 234 and / or 235 (according to EU numbering) of human immunoglobulin (e.g., IgG1). In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise two amino acid substitutions at positions 234 and 235 (according to EU numbering) of human immunoglobulin (e.g., IgG1). In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise amino acid substitutions L234A and L235A (according to EU numbering).

[0246] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise one or more amino acid substitutions at position 228 (according to EU numbering) of a human immunoglobulin (e.g., IgG4). In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise the amino acid substitution S228P (according to EU numbering).

[0247] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein comprise one or more amino acid substitutions at the interface of the Fc region to promote and / or enhance heterodimerization. These modifications include the introduction of a protrusion into the first Fc polypeptide and a cavity into the second Fc polypeptide, where the protrusion may be positioned within the cavity to enhance the interaction of the first and second Fc polypeptides to form a heterodimer or complex. Methods for generating antibodies with these modifications are known in the art, for example, as described in U.S. Patent No. 5,731,168. antigen binding fragment

[0248] Also provided herein are anti-LILRB2 antigen-binding fragments. Various types of antigen-binding fragments are known in the art and can be developed based on the anti-LILRB2 antibodies provided herein, including, for example, the exemplary antibodies whose CDRs are shown in Table 2 above and whose variable sequences are shown in Table 3 above, and different variants thereof (such as affinity variants, glycosylation variants, Fc variants, and cysteine-engineered variants).

[0249] In certain embodiments, the anti-LILRB2 antigen-binding fragment provided herein is a diabody, Fab, Fab', F(ab')2, Fd, Fv fragment, disulfide-stabilized Fv fragment (dsFv), (dsFv)2, bispecific dsFv (dsFv-dsFv'), disulfide-stabilized diabody (dsdiabody), single-chain antibody molecule (scFv), scFv dimer (bivalent diabody), camelized single-domain antibody, nanobody, domain antibody, or bivalent domain antibody.

[0250] Various techniques can be used to produce such antigen-binding fragments. Exemplary methods include enzymatic digestion of intact antibodies (see, e.g., Morimoto et al., Journal of Biochemical and Biophysical Methods 24:107-117 (1992), and Brennan et al., Science, 229:81 (1985)), recombinant expression (e.g., of Fab, Fv, and ScFv antibody fragments) by host cells such as E. coli, screening (e.g., of ScFv) from phage display libraries as discussed above, and chemical coupling of two Fab'-SH fragments to form an F(ab')2 fragment (Carter et al., Bio / Technology 10:163-167 (1992)). Other techniques for producing antibody fragments will be apparent to those skilled in the art.

[0251] In certain embodiments, the antigen-binding fragment is an scFv. The production of scFvs is described, for example, in WO 93 / 16185, U.S. Patent Nos. 5,571,894 and 5,587,458. ScFvs may be fused to effector proteins at the amino or carboxyl terminus to provide fusion proteins (see, e.g., Antibody Engineering, ed. Borrebaeck).

[0252] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein are bivalent, tetravalent, hexavalent, or multivalent. Any molecule with more than two valencies is considered multivalent, including, for example, trivalent, tetravalent, and hexavalent.

[0253] A bivalent molecule may be monospecific if both binding sites specifically bind to the same antigen or epitope. This, in certain embodiments, provides stronger binding to the antigen or epitope than its monovalent counterpart. Similarly, a multivalent molecule may be monospecific. In certain embodiments, in a bivalent or multivalent antigen-binding moiety, the first and second binding sites are structurally identical (i.e., have the same sequence) or structurally different (i.e., have the same specificity but different sequences).

[0254] A bivalent molecule can also be bispecific if the two binding sites are specific for different antigens or epitopes. This is also true for multivalent molecules. For example, a trivalent molecule can be bispecific if two binding sites are monospecific for a first antigen (or epitope) and the third binding site is specific for a second antigen (or epitope). Bispecific or multispecific antibodies

[0255] In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein are bispecific or multispecific. In certain embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein are further linked to a second functional moiety having a binding specificity different from that of the anti-LILRB2 antibody or antigen-binding fragment thereof. In some embodiments, the bispecific or multispecific antibodies or antigen-binding fragments thereof provided herein have a first specificity for LILRB2 and a second specificity. In some embodiments, the second specificity is for LILRB2 but for a different epitope. In some embodiments, the second specificity is for a second antigen different from LILRB2.

[0256] In certain embodiments, the second specificity is for a tumor-associated antigen or an epitope thereof. The term "tumor-associated antigen" refers to an antigen that is or can be presented on the surface of tumor cells and is located on or within tumor cells. In some embodiments, the tumor-associated antigen may be presented only by tumor cells and not by normal cells, i.e., non-tumor cells. In some other embodiments, the tumor-associated antigen may be expressed only by tumor cells or may exhibit tumor-specific mutations compared to non-tumor cells. In some other embodiments, the tumor-associated antigen is found in both tumor and non-tumor cells, but is overexpressed in tumor cells compared to non-tumor cells, or is more accessible to antibody binding in tumor cells due to the lack of compactness of tumor tissue compared to non-tumor tissue. In some embodiments, the tumor-associated antigen is located in the tumor vasculature.

[0257] In certain embodiments, the bispecific or multispecific antibodies or antigen-binding fragments thereof provided herein are capable of binding to one or more (e.g., 1, 2, 3, 4, 5 or more) additional antigens other than LILRB2, or a second epitope on LILRB2.In certain embodiments, the one or more additional antigens other than LILRB2 are CD3, CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, Flt3, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP, TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, DLL3 , HER-2, C10orf54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1 / 2, PAK4, NAMPT, ATR, EGFR, FGFR, VEGF, c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD2, CD7, CD16, CD19, CD20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80(B7-1), CD86(B7-2), CD40, CD40L(CD154), CD47, SIRPα , CD122, CD137, CD137L, OX40(CD134), OX40L(CD252), BCMA (e.g. BCMA02), PSMA, CLDN18 (e.g. CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAMF7 , HVEM, BAFFR, ICAM-1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD27) 2), CD160, CTLA-4 (CD152), GPRC5D, IDO1, IDO2, TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), LILRB1, LILRB3, LILRB4, LILRB5, FLT3L, TLR3, CLEC9A, DEC-205, STING, IL-12, IDO, and TGFβ.

[0258] In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and CD3. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and BCMA. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and CD38. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and CD19. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and FcRH5. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and PD-L1. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and PD-1. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and CD24. In certain embodiments, the bispecific antibodies or antigen-binding fragments thereof provided herein bind to LILRB2 and FLT3L. Conjugates

[0259] In some embodiments, the anti-LILRB2 antibodies or antigen-binding fragments thereof provided herein further comprise one or more conjugate moieties. The conjugate moiety can be linked to an antibody or antigen-binding fragment thereof. The conjugate moiety is a moiety that can bind to an antibody or antigen-binding fragment thereof. It is contemplated that various conjugate moieties can be linked to the antibodies or antigen-binding fragments thereof provided herein (see, for example, "Conjugate Vaccines," Contributions to Microbiology and Immunology, JM Cruse and RE Lewis, Jr. (eds.), Carger Press, New York, (1989)). These conjugate moieties may be linked to the antibody or antigen-binding fragment thereof by methods such as covalent bonding (e.g., disulfide bonding), affinity binding, intercalation, coordinate bonding, complex formation, association, blending, or attachment. In some embodiments, the antibody or antigen-binding fragment thereof may be linked to one or more conjugates via a linker or cross-linking agent. The linker or cross-linking agent comprises a reactive chemical group that can react with an anti-LILRB2 antibody or fragment thereof. The reactive chemical groups can be N-succinimidyl esters and N-sulfosuccinimidyl esters. Additionally, the linker contains a reactive chemical group that can be a dithiopyridyl group that can react with a drug to form a disulfide bond.Examples of linker molecules include N-succinimidyl 4-(maleimidomethyl)cyclohexanecarboxylate (SMCC), N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) (see, e.g., Carlsson et al., Biochem. J., 173: 723-737). (1978)), N-succinimidyl 4-(2-pyridyldithio)butanoate (SPDB) (see, e.g., U.S. Pat. No. 4,563,304), N-succinimidyl 4-(2-pyridyldithio)2-sulfobutanoate (sulfo-SPDB) (see, U.S. Publication No. 20090274713), N-succinimidyl 4-(2-pyridyldithio)pentanoate (SPP) (see, e.g., CAS Registry No. 341498-08-6), 2-iminothiolane, or acetylsuccinic anhydride. For example, an antibody or cell-binding agent can be modified with a cross-linking reagent, and the resulting antibody or cell-binding agent containing free or protected thiol groups can then be reacted with a disulfide- or thiol-containing maytansinoid to produce a conjugate. The conjugate can be purified by chromatography, including but not limited to HPLC, size exclusion, adsorption, ion exchange and affinity capture, dialysis, or tangential flow filtration.

[0260] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein can be engineered to contain specific sites outside the epitope-binding portion that can be utilized for binding to one or more conjugate moieties. For example, such sites can include one or more reactive amino acid residues, such as cysteine ​​or histidine residues, to facilitate covalent linkage to a conjugate moiety.

[0261] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein may be linked to a conjugate moiety directly or via another conjugate moiety. For example, the antibodies or antigen-binding fragments thereof provided herein may be conjugated to biotin and then indirectly conjugated to a second conjugate conjugated to avidin. In some embodiments, the conjugate moiety comprises a clearance modifier (e.g., a polymer that extends half-life, such as PEG), a chemotherapeutic agent, a toxin, a radioisotope, a lanthanide, a detectable label (e.g., a luminescent label, a fluorescent label, an enzyme-substrate label), a DNA alkylating agent, a topoisomerase inhibitor, a tubulin-binding agent, a purification moiety, or another anti-cancer drug (e.g., an agonist of Toll-like receptor 7 (TLR-7), TLR-8, and / or TLR-9, an siRNA, an antibody or antigen-binding fragment thereof, a peptide (such as a short peptide), etc.).

[0262] A "toxin" can be any agent that is detrimental to cells or can damage or kill cells. Examples of toxins include taxol, taxoids, CC-1065 and CC-1065 analogs, duocamycin and duocamycin analogs, enediynes such as calicheamicin, dolastatins and dolastatin analogs, including auristatins, tomaymycin derivatives, leptomycin derivatives, cisplatin, carboplatin, daunorubicin, doxorubicin, vincristine, vinblastine, melphalan, mitomycin C, chlorambucil, and mogamulizumab. Irrholinodoxorubicin, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, MMAE, MMAF, DM1, DM4, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthracin dione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, Docaine, propranolol, puromycin and its analogs, antimetabolites (e.g., methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracil dacarbazine), alkylating agents (e.g., mechlorethamine, thioepaclorambucil, melphalan, carmustine (BSNU) and lomustine (CCNU), cyclophosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C, and cis-dichlorodiamineplatinum(II) (DDP) cisplatin, anthracyclines (e.g., daunorubicin (formerly daunomycin) and doxorubicin), antibiotics (e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin, and anthramycin (AMC)), antimitotic agents (e.g., vincristine and vinblastine), topoisomerase inhibitors, and tubulin binding agents.

[0263] Examples of detectable labels include fluorescent labels (e.g., fluorescein, rhodamine, dansyl, phycoerythrin, or Texas Red), enzyme-substrate labels (e.g., horseradish peroxidase, alkaline phosphatase, lucerifers, glucoamylase, lysozyme, saccharide oxidases, or β-D-galactosidase), radioisotopes (e.g., 123 I, 124 I, 125 I, 131 I, 35 S, 3 H, 111 In, 112 In, 14 C. 64 Cu, 67 Cu, 86 Y, 88 Y, 90 Y, 177 Lu, 211 At, 186 Re, 188 Re, 153 Sm, 212 Bi, and 32 P, other lanthanides), luminescent labels, plastid moieties, digoxigenin, biotin / avidin, DNA molecules, or gold for detection.

[0264] In certain embodiments, the conjugate moiety may be a clearance modifier, which serves to extend the half-life of the antibody. Illustrative examples include water-soluble polymers such as PEG, carboxymethylcellulose, dextran, polyvinyl alcohol, polyvinylpyrrolidone, and ethylene glycol / propylene glycol copolymers. The polymer may be of any molecular weight and may be branched or unbranched. The number of polymers attached to the antibody may vary, and when two or more polymers are attached, they may be the same or different molecules.

[0265] In certain embodiments, the conjugated moiety can be a purification moiety such as a magnetic bead.

[0266] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are used as the basis for a conjugate.

[0267] In certain embodiments, the antibodies or antigen-binding fragments thereof provided herein are conjugated to a signal peptide. Signal peptides (sometimes referred to as signal sequences, leader sequences, or leader peptides) can be used to facilitate secretion and isolation of the antibodies or antigen-binding fragments thereof provided herein. Signal peptides are typically characterized by a core of hydrophobic amino acids that are generally cleaved from the mature protein during secretion in one or more cleavage events. Such signal peptides contain processing sites that allow cleavage of the signal sequence from the mature protein as it passes through the secretory pathway. Thus, the present invention relates to the described polypeptides having a signal sequence, as well as polypeptides from which the signal sequence has been proteolytically cleaved (i.e., cleavage products). In one embodiment, a nucleic acid sequence encoding a signal sequence can be operably linked to a protein of interest in an expression vector, such as a protein that is not normally secreted or otherwise difficult to isolate. The signal sequence directs secretion of the protein, for example, from a eukaryotic host into which the expression vector is transformed, followed by or concurrent with cleavage of the signal sequence. The protein can then be readily purified from the extracellular medium by art-recognized methods. Alternatively, a sequence that facilitates purification may be used to link a signal sequence to the protein of interest, for example, by a GST domain. Chimeric Antigen Receptor

[0268] In certain embodiments, the present disclosure provides a chimeric antigen receptor comprising an antibody or antigen-binding fragment thereof provided herein, a transmembrane region, and an intracellular signaling region.

[0269] The term "chimeric antigen receptor" or "CAR" or "CAR," as used herein, refers to an engineered receptor that confers antigen specificity to a cell (e.g., a T cell, such as a naive T cell, a central memory T cell, an effector memory T cell, a regulatory T cell, a natural killer cell, or a combination thereof). CARs are also known as artificial T-cell receptors, chimeric T-cell receptors, or chimeric immune receptors. In some embodiments, a CAR comprises an antigen-specific targeting region (e.g., an antigen-binding fragment of an anti-LILRB2 antibody provided herein), an extracellular region, a transmembrane region, one or more costimulatory regions, and an intracellular signaling region.

[0270] In some embodiments, the antigen-specific targeting region is an scFv. In some embodiments, the transmembrane region comprises the transmembrane region of CD3, CD4, CD8, or CD28. In some embodiments, the costimulatory region comprises the costimulatory domain of CD28, ICOS, CD27, 4-1BB, OX40, and CD40L. In some embodiments, the intracellular signaling region is selected from the group consisting of intracellular signaling region sequences of CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR, or a combination thereof.

[0271] CARs can be implanted into a variety of cells, for example, allogeneic, autologous, or xenogeneic cells.

[0272] The term "allogeneic cells," as used herein, refers to any cells derived from a different subject of the same species.

[0273] The term "autologous cells," as used herein, refers to any cells derived from the same subject into whom the autologous cells are subsequently reintroduced.

[0274] The term "xenogeneic cell," as used herein, refers to any cell derived from a different subject of a different species.

[0275] In some embodiments, the CAR is grafted onto an immune effector cell, such as a T cell, a natural killer cell, a macrophage cell, a tumor-infiltrating lymphocyte, or the like. Polynucleotides and Recombinant Methods

[0276] The present disclosure provides isolated polynucleotides encoding the antibodies or antigen-binding fragments thereof, and / or chimeric antigen receptors provided herein. As used herein, the terms "nucleic acid" or "polynucleotide" refer to deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) and polymers thereof in single- or double-stranded form. Unless otherwise indicated, a particular polynucleotide sequence implicitly encompasses not only the sequence explicitly indicated, but also conservatively modified variants thereof (e.g., degenerate codon substitutions), alleles, orthologs, SNPs, and complementary sequences. Specifically, degenerate codon substitutions can be achieved by generating sequences in which the third position of one or more (or all) selected codons is substituted with mixed-base and / or deoxyinosine residues (see Batzer et al., Nucleic Acid Res. 19:5081 (1991); Ohtsuka et al., J. Biol. Chem. 260:2605-2608 (1985); and Rossolini et al., Mol. Cell. Probes 8:91-98 (1994)).

[0277] DNA encoding the antibodies or antigen-binding fragments thereof provided herein is readily isolated and sequenced by conventional procedures (e.g., oligonucleotide probes capable of binding specifically to genes encoding the heavy and light chains of the antibody). The encoding DNA may also be obtained by synthetic methods.

[0278] Isolated polynucleotides encoding the antibodies or antigen-binding fragments thereof and / or chimeric antigen receptors provided herein may be inserted into vectors for further cloning (amplification of the DNA) or expression by recombinant techniques known in the art. Many vectors are available. Vector components generally include, but are not limited to, one or more of a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter (e.g., SV40, CMV, EF-1α), and a transcription termination sequence.

[0279] The present disclosure provides vectors comprising the isolated polynucleotides provided herein. In certain embodiments, the polynucleotides provided herein encode the antibodies or antigen-binding fragments thereof and / or chimeric antigen receptors provided herein, at least one promoter (e.g., SV40, CMV, EF-1α) operably linked to the nucleic acid sequence, and at least one selectable marker. Examples of vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpesviruses (e.g., herpes simplex viruses), poxviruses, baculoviruses, papillomaviruses, papovaviruses (e.g., SV40), lambda phage, and M13 phage, as well as the plasmids pcDNA3.3, pMD18-T, pOptivec, pCMV, pEGFP, pIRES, pQD-Hyg-GSeu, pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX, pGEX, and pC Examples of such vectors include, but are not limited to, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS10, pLexA, pACT2.2, pCMV-SCRIPT.RTM., pCDM8, pCDNA1.1 / amp, pcDNA3.1, pRc / RSV, PCR2.1, pEF-1, pFB, pSG5, pXT1, pCDEF3, pSVSPORT, and pEF-Bos.

[0280] Vectors comprising polynucleotide sequences encoding the antibodies or antigen-binding fragments thereof and / or chimeric antigen receptors provided herein may be introduced into a host expression system (e.g., a host cell) for cloning or gene expression. In certain embodiments, the host expression systems provided herein are microorganisms, yeast, or mammalian cells. In certain embodiments, the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis. In certain embodiments, the yeast is Saccharomyces. In certain embodiments, the mammalian cells are selected from the group consisting of COS, CHO-S, CHO-K1, HEK-293, and 3T3 cells.

[0281] Suitable host cells for cloning or expressing DNA in the vectors herein are the prokaryotes, yeast, or higher eukaryote cells described above. Suitable prokaryotic cells for this purpose include eubacteria, such as Gram-negative or Gram-positive organisms, e.g., Enterobacteriaceae such as Escherichia, e.g., Escherichia coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella such as Salmonella typhimurium, Serratia marcescans, and Shigella, as well as Bacillus species such as Bacillus subtilis and B. licheniformis, Pseudomonas species such as Pseudomonas aeruginosa, and Streptomyces.

[0282] In addition to prokaryotes, eukaryotic microbes, such as filamentous fungi or yeast, are suitable cloning or expression hosts for vectors encoding anti-LILRB2 antibodies. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among lower eukaryotic host microorganisms. However, numerous other genera, species, and strains are commonly available and useful herein, including Schizosaccharomyces pombe, e.g., Kluyveromyces lactis, Kluyveromyces fragilis (ATCC 12,424), Kluyveromyces bulgaricus (ATCC 16,045), Kluyveromyces wickelamii (ATCC 24,178), Kluyveromyces wartii (ATCC 56,500), Kluyveromyces drosophilarum (ATCC 36,906), and Kluyveromyces thermotolerans. and Kluyveromyces marxianus; Yarrowia (EP 402,226), Pichia pastoris (EP 183,070), Candida, Trichoderma reesia (EP 244,234), Neurospora crassa; Schwanniomyces species such as Schwanniomyces occidentalis; and filamentous fungi such as Neurospora crassa, Penicillium, and Tolypocladium; and Aspergillus hosts such as Aspergillus nidulans and Aspergillus niger.

[0283] Suitable host cells for expressing the glycosylated antibodies or antigenic fragments thereof provided herein are derived from multicellular organisms. Examples of invertebrate cells include plant cells and insect cells. Numerous baculovirus strains and variants have been identified, as well as corresponding permissive insect host cells from hosts such as the armyworm (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruit fly), and Bombyx mori. Various virus strains for transfection, such as the L-1 variant of the mosquito virus (NPV) and the Bm-5 strain of the silkworm NPV, are publicly available, and such viruses can be used in accordance with the present invention, particularly for transfection of armyworm cells. Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco can also be used as hosts.

[0284] However, vertebrate cells have received the most attention, and propagation of vertebrate cells in culture (tissue culture) has become routine. Examples of useful mammalian host cell lines include SV40-transformed monkey kidney CV1 (COS-7, ATCC CRL 1651), human embryonic kidney (293 or 293 cells subcloned for growth in suspension culture, Graham et al., J. Gen. Virol. 36:59 (1977)), baby hamster kidney cells (BHK, ATCC CCL 10), Chinese hamster ovary cells / -DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci. USA 77:4216 (1980)), mouse Sertoli cells (TM4, Mather, Biol. Reprod. 23:243-251 (1980)), monkey kidney cells (CV1 ATCC CCL 70), African green monkey kidney cells (VERO-76, ATCC CRL-1587), human cervical carcinoma cells (HELA, ATCC CCL 2), canine kidney cells (MDCK, ATCC CCL 34), buffalo rat hepatocytes (BRL 3A, ATCC CRL 1442), human lung cells (W138, ATCC CCL 75), human hepatocytes (Hep G2, HB 8065), mouse mammary tumor (MMT 060562, ATCC CCL51), TRI cells (Mather et al., Annals NY Acad. Sci. 383:44-68 (1982)), MRC 5 cells, FS4 cells, mouse forestomach carcinoma cells (MFC), SNU620 cells, and a human hepatocellular carcinoma line (Hep G2). In some embodiments, the host cell is a mammalian cultured cell line such as CHO, BHK, NS0, 293, MFC, SNU620, and their derivatives.

[0285] Host cells are transformed with the above-described antibody-producing expression or cloning vectors and cultured in conventional nutrient media modified as appropriate for inducing promoters, selecting transformants, or amplifying genes encoding the desired sequences. In another embodiment, antibodies may be produced by homologous recombination, as known in the art. In certain embodiments, host cells are capable of producing the antibodies or antigen-binding fragments thereof provided herein.

[0286] The present disclosure also provides a method for expressing an antibody or antigen-binding fragment thereof, or chimeric antigen receptor provided herein, the method comprising culturing a host expression system provided herein under conditions such that the antibody or antigen-binding fragment thereof, or chimeric antigen receptor is expressed. The host expression system used to produce the antibody or antigen-binding fragment thereof, or chimeric antigen receptor provided herein can be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma), Minimal Essential Medium (MEM) (Sigma), RPMI-1640 (Sigma), and Dulbecco's Modified Eagle's Medium (DMEM) (Sigma) are suitable for culturing host cells. Additionally, any of the media described in Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal. Biochem. 102:255 (1980), U.S. Pat. Nos. 4,767,704, 4,657,866, 4,927,762, 4,560,655, or 5,122,469, WO90 / 03430, WO87 / 00195, or U.S. Pat. No. 30,985 can be used as a culture medium for host cells. Any of these media can be supplemented as needed with hormones and / or other growth factors (such as insulin, transferrin, or epidermal growth factor), salts (such as sodium chloride, calcium, magnesium, and phosphate), buffers (such as HEPES), nucleotides (such as adenosine and thymidine), antibiotics (such as the drug GENTAMYCIN™), trace elements (usually defined as inorganic compounds present at final concentrations in the micromolar range), and glucose or an equivalent energy source. Any other necessary supplements can also be included at appropriate concentrations known to those skilled in the art. Culture conditions, such as temperature and pH, will be those previously used with the host cell selected for expression and will be apparent to those skilled in the art.

[0287] When using recombinant techniques, antibodies may be produced intracellularly, in the periplasmic space, or directly secreted into the culture medium. If the antibody is produced intracellularly, as a first step, particulate cell debris, either host cells or lysed fragments, is removed, for example, by centrifugation or ultrafiltration. Carter et al., Bio / Technology 10:163-167 (1992) describes a procedure for isolating antibodies secreted into the periplasmic space of E. coli. Briefly, cell paste is thawed for approximately 30 minutes in the presence of sodium acetate (pH 3.5), EDTA, and phenylmethylsulfonyl fluoride (PMSF). Cell debris can be removed by centrifugation. If the antibody is secreted into the culture medium, the supernatant from such expression systems is typically first concentrated using a commercially available protein concentration filter, e.g., an Amicon or Millipore Pellicon ultrafiltration unit. Protease inhibitors, such as PMSF, may be included in any of the above steps to inhibit proteolysis, and antibiotics may be included to prevent the growth of adventitious contaminants.

[0288] The antibody or antigen-binding fragment thereof and / or chimeric antigen receptor prepared from the host expression system can be purified using, for example, hydroxylapatite chromatography, gel electrophoresis, dialysis, DEAE-cellulose ion exchange chromatography, ammonium sulfate precipitation, salting out, and affinity chromatography, with affinity chromatography being preferred.

[0289] In certain embodiments, solid-phase-immobilized protein A is used for immunoaffinity purification of antibodies and their antigen-binding fragments and / or chimeric antigen receptors. The suitability of protein A as an affinity ligand depends on the species and isotype of any immunoglobulin Fc domain present in the antibody. Protein A can be used to purify antibodies based on human γ1, γ2, or γ4 heavy chains (Lindmark et al., J. Immunol. Meth. 62:1-13 (1983)). Protein G is recommended for all mouse isotypes and human γ3 (Guss et al., EMBO J. 5:1567 1575 (1986)). The matrix to which the affinity ligand is attached is most often agarose, although other matrices can also be used. Mechanically stable matrices such as controlled pore glass or poly(styrenedivinyl)benzene allow for faster flow rates and shorter processing times than agarose. If the antibody contains a CH3 domain, Bakerbond ABX® resin (JT Baker, Phillipsburg, NJ) is useful for purification. Depending on the antibody recovered, other protein purification techniques can be used, such as fractionation on an ion exchange column followed by ethanol precipitation, reverse-phase HPLC, chromatography on silica, chromatography on heparin SEPHAROSE™, chromatography on anion or cation exchange resins (such as polyaspartic acid columns), chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation.

[0290] Following any preliminary purification steps, the mixture containing the antibody of interest and contaminants may be subjected to low pH hydrophobic interaction chromatography using an elution buffer of about pH 2.5 to 4.5, preferably at a low salt concentration (e.g., about 0 to 0.25 M salt). Pharmaceutical Composition

[0291] The present disclosure further provides pharmaceutical compositions comprising an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor provided herein and one or more pharmaceutically acceptable carriers.

[0292] Pharmaceutically acceptable carriers for use in pharmaceutical compositions may include, for example, pharmaceutically acceptable liquid, gel, or solid carriers, aqueous vehicles, non-aqueous vehicles, antibacterial agents, isotonic agents, buffers, antioxidants, anesthetics, suspending / dispersing agents, sequestering or chelating agents, diluents, adjuvants, excipients, or other non-toxic auxiliary substances, or other ingredients known in the art, or various combinations thereof.

[0293] Suitable ingredients herein may include, for example, antioxidants, fillers, binders, disintegrants, buffers, preservatives, lubricants, flavorings, thickeners, coloring agents, emulsifiers, or stabilizers such as sugars and cyclodextrins. Suitable antioxidants may include, for example, methionine, ascorbic acid, EDTA, sodium thiosulfate, platinum, catalase, citric acid, cysteine, thioglycerol, thioglycolic acid, thiosorbitol, butylated hydroxyanisole, butylated hydroxytoluene, and / or propyl gallate. As disclosed herein, the inclusion of one or more antioxidants, such as methionine, in compositions comprising the antibodies or antigen-binding fragments thereof and conjugates provided herein reduces oxidation of the antibodies or antigen-binding fragments thereof. This reduction in oxidation prevents or reduces loss of binding affinity, thereby improving antibody stability and maximizing shelf life. Accordingly, in certain embodiments, provided are pharmaceutical compositions comprising one or more antibodies or antigen-binding fragments thereof disclosed herein and one or more antioxidants, such as methionine. Further provided are methods for preventing oxidation of, extending the shelf life of, and / or improving the efficacy of, the antibodies or antigen-binding fragments provided herein by combining the antibodies or antigen-binding fragments with one or more antioxidants, such as methionine.

[0294] By way of further example, pharmaceutically acceptable carriers may include, for example, aqueous vehicles such as sodium chloride injection, Ringer's injection, isotonic dextrose injection, sterile water injection, or dextrose and lactated Ringer's injection; non-aqueous vehicles such as fixed oils of vegetable origin, cottonseed oil, corn oil, sesame oil, or peanut oil; antibacterial agents in bacteriostatic or fungistatic concentrations; isotonic agents such as sodium chloride or dextrose; buffers such as phosphate or citrate buffers; antioxidants such as sodium bisulfate; local anesthetics such as procaine hydrochloride; suspending and dispersing agents such as sodium carboxymethylcellulose, hydroxypropyl methylcellulose, or polyvinylpyrrolidone; emulsifying agents such as polysorbate 80 (TWEEN-80); sequestrants or chelating agents such as EDTA (ethylenediaminetetraacetic acid) or EGTA (ethylene glycol tetraacetic acid); ethyl alcohol, polyethylene glycol, propylene glycol, sodium hydroxide, hydrochloric acid, citric acid, or lactic acid. Antibacterial agents used as carriers may be added to pharmaceutical compositions in multi-dose containers and include phenol or cresol, mercurials, benzyl alcohol, chlorobutanol, methyl and propyl p-hydroxybenzoic acid esters, thimerosal, benzalkonium chloride, and benzethonium chloride. Suitable excipients may include, for example, water, saline, dextrose, glycerol, or ethanol. Suitable non-toxic auxiliary substances may include, for example, wetting or emulsifying agents, pH buffers, stabilizers, solubility enhancers, or agents such as sodium acetate, sorbitan monolaurate, triethanolamine oleate, or cyclodextrins.

[0295] The pharmaceutical compositions may be liquid solutions, suspensions, emulsions, pills, capsules, tablets, sustained-release formulations, or powders. Oral formulations may include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, polyvinylpyrrolidone, sodium saccharin, cellulose, magnesium carbonate, etc.

[0296] In certain embodiments, the pharmaceutical composition is formulated into an injectable composition. The injectable pharmaceutical composition can be prepared in any conventional form, such as a liquid solution, suspension, emulsion, or solid form suitable for preparing a liquid solution, suspension, or emulsion. Preparations for injection can include sterile and / or non-pyrogenic solutions prepared for injection, sterile dry soluble preparations such as lyophilized powders prepared to be combined with a solvent immediately before use, including hypodermic tablets, sterile suspensions prepared for injection, sterile dry insoluble preparations prepared to be combined with a vehicle immediately before use, and sterile and / or non-pyrogenic emulsions. The solution can be aqueous or non-aqueous.

[0297] In certain embodiments, unit dose parenteral preparations are packaged in ampoules, vials, or syringes with needles. All preparations for parenteral administration shall be sterile and non-pyrogenic, as known and practiced in the art.

[0298] In certain embodiments, a sterile, lyophilized powder is prepared by dissolving an antibody or antigen-binding fragment disclosed herein in a suitable solvent. The solvent may contain an excipient that improves the stability or other pharmacological components of the powder or a reconstituted solution prepared from the powder. Excipients that may be used include, but are not limited to, water, dextrose, sorbitol, fructose, corn syrup, xylitol, glycerin, glucose, sucrose, or other suitable agents. The solvent may contain a buffer such as citric acid, sodium phosphate, or potassium phosphate, or other such buffers known to those of skill in the art, in one embodiment at about neutral pH. Subsequent sterile filtration of the solution, followed by lyophilization under standard conditions known to those of skill in the art, provides the desired formulation. In one embodiment, the resulting solution is apportioned into vials for lyophilization. Each vial may contain a single dose or multiple doses of the antibody or antigen-binding fragment thereof, or a composition thereof. Overfilling the vial with a small amount (e.g., about 10%) beyond that required for the dose or set of doses may be acceptable to facilitate accurate sample draws and accurate dosing. The lyophilized powder may be stored under appropriate conditions, such as at about 4°C to room temperature.

[0299] Reconstitution of the lyophilized powder with water for injection provides a formulation for use in parenteral administration. In one embodiment, sterile and / or non-pyrogenic water or other suitable liquid carrier is added to the lyophilized powder for reconstitution. The exact amount depends on the given selected therapy and can be determined empirically. kit

[0300] In certain embodiments, the present disclosure provides a kit comprising an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein. In certain embodiments, the present disclosure provides a kit comprising an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein and a second therapeutic agent. In certain embodiments, the second therapeutic agent is selected from the group consisting of a chemotherapeutic agent, an anticancer drug, a radiation therapy agent, an immunotherapy agent, an antiangiogenic agent, a targeted therapy agent, a cell therapy agent, a gene therapy agent, a hormonal therapy agent, an antiviral agent, an antibiotic, an analgesic, an antioxidant, a metal chelator, and a cytokine.

[0301] As will be readily apparent to one of skill in the art, such kits may optionally further include one or more of a variety of conventional pharmaceutical kit components, e.g., containers containing one or more pharmaceutically acceptable carriers, additional containers, etc. Instructions as an insert or label indicating the amounts of components to be administered, administration guidelines, and / or guidelines for mixing the components may also be included in the kit. How to use

[0302] The present disclosure also provides methods for treating, preventing, or alleviating a disease, disorder, or condition in a subject, comprising administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein. In certain embodiments, the disease, disorder, or condition is a LILRB2-associated disease, disorder, or condition. In certain embodiments, the subject is a human.

[0303] In some embodiments, the LILRB2-associated disease, disorder, or condition is characterized by expression or overexpression of LILRB2.

[0304] In certain embodiments, the disease, disorder, or condition is an immune disease, an inflammatory disease, cancer, or a neurological disease. In certain embodiments, the cancer is a LILRB2-expressing cancer. As used herein, a "LILRB2-expressing" cancer refers to a cancer characterized by expression of LILRB2 protein in cancer cells, tumor-infiltrating immune cells, or expression of LILRB2 in cancer cells, tumor-infiltrating immune cells at levels significantly higher than those expected in normal cells. Various methods can be used to determine the presence and / or amount of LILRB2 in a test biological sample from a subject. For example, the test biological sample can be exposed to an anti-LILRB2 antibody or an antigen-binding fragment thereof that binds to and detects expressed LILRB2 protein. Alternatively, LILRB2 can be detected at the nucleic acid expression level by methods such as qPCR, reverse transcriptase PCR, microarray, SAGE, and FISH. In some embodiments, the test sample is derived from cancer cells or tissue, or tumor-infiltrating immune cells. The reference sample may be a control sample taken from a healthy or non-diseased individual, or a healthy or non-diseased sample taken from the same individual from whom the test sample is taken. For example, the reference sample may be a non-diseased sample adjacent to or near the test sample (e.g., tumor). In certain embodiments, the cancer is a solid tumor or a hematological tumor. In certain embodiments, the cancer is a LILRB2-expressing B-cell cancer.

[0305] In certain embodiments, the disease, disorder, or condition is Kawasaki disease, toxoplasmosis, multiple sclerosis, systemic lupus erythematosus, lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), lung adenocarcinoma, lung squamous cell carcinoma, or Lewis lung carcinoma), peritoneal cancer, carcinoid cancer, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), cancer of the anal region (e.g., anal squamous cell carcinoma), stomach cancer (e.g., gastrointestinal cancer), esophageal cancer, colon cancer, breast cancer, uterine cancer, liver cancer (e.g., cancer of the urethra, penile cancer, kidney or ureter (e.g., rhabdoid tumor of the kidney), cutaneous T-cell lymphoma, medulloblastoma, nephroblastoma, myelodysplastic syndrome, chronic and non-chronic myeloproliferative disorders, choroid plexus papilloma, renal cell carcinoma, renal pelvis cancer, central nervous system (CNS) tumors, soft tissue sarcomas (e.g., rhabdoid tumor of the kidney, urethral cancer ... sarcoma), spinal axis tumor, glioma (e.g., ependymoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma, eye cancer (e.g., retinoblastoma), brain stem glioma, or mixed glioma such as oligoastrocytoma), brain tumor (e.g., glioblastoma / glioblastoma multiforme (GBM), non-glioblastoma brain tumor, or meningioma), melanoma (e.g., cutaneous melanoma or intraocular melanoma), thrombocythemia, mesothelioma, mycosis fungoides, Sézary syndrome, idiopathic myelofibrosis, solitary plasmacytoma, vestibular schwannoma, Ewing's sarcoma, chondrosarcoma, MYH-associated polyposis, pituitary adenoma, pediatric sarcoma (e.g., neuroblastoma, childhood cancers such as rhabdomyosarcoma, osteosarcoma, and osteosarcoma, blood cancers, Hodgkin's lymphoma, non-Hodgkin's lymphoma, leukemia (e.g., lymphocytic / lymphoblastic leukemia), chronic or acute leukemia, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g.,In some embodiments, the disease, disorder, or condition is selected from the group consisting of: relapsed or refractory multiple myeloma), T-cell or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary mediastinal large B-cell lymphoma, follicular lymphoma (FL), and primary mediastinal B-cell lymphoma. In some embodiments, the disease, disorder, or condition is acute myeloid leukemia. In some embodiments, the disease, disorder, or condition is chronic myelomonocytic leukemia.

[0306] In some embodiments, the subject has been identified as having cancer cells or tumor-infiltrating immune cells that express LILRB2, optionally at levels significantly higher than those generally observed in non-cancerous cells.

[0307] In another aspect, provided is a method for treating, preventing, or alleviating a disease, disorder, or condition in a subject endowed with regulated LILRB2 activity, comprising administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein. In certain embodiments, the disease, disorder, or condition is a LILRB2-associated disease, disorder, or condition as defined above.

[0308] The therapeutically effective amount of an antibody or antigen-binding fragment provided herein will depend on various factors known in the art, such as the subject's weight, age, past medical history, current drug treatments, health status and potential for cross-reactivity, allergies, hypersensitivity and side effects, as well as the route of administration and the extent of disease development. Doses can be proportionally increased or decreased by one skilled in the art (e.g., a physician or veterinarian) depending on these and other circumstances or requirements.

[0309] In certain embodiments, the antibodies or antigen-binding fragments provided herein and / or chimeric antigen receptors provided herein may be administered at a therapeutically effective dose of about 0.01 mg / kg to 100 mg / kg. In certain embodiments, the administered dose may vary over the course of treatment. For example, in certain embodiments, an initial administered dose may be higher than subsequent administered doses. In certain embodiments, the administered dose may vary over the course of treatment depending on the subject's response.

[0310] Dosage regimens may be adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a single dose may be administered or several divided doses may be administered over time.

[0311] The antibodies or antigen-binding fragments thereof provided herein and / or chimeric antigen receptors provided herein can be administered by any route known in the art, for example, parenteral routes including subcutaneous, intraperitoneal, intravenous, intramuscular, or intradermal injection, or non-parenteral routes including transdermal, oral, intranasal, intraocular, sublingual, rectal, or topical.

[0312] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein and / or the chimeric antigen receptors provided herein may be administered alone or in combination with a therapeutically effective amount of a second therapeutic agent. For example, the antibodies or antigen-binding fragments thereof disclosed herein and / or the chimeric antigen receptors provided herein may be administered in combination with a second therapeutic agent, such as a chemotherapeutic agent, an anticancer drug, a radiotherapeutic agent, an immunotherapeutic agent, a targeted therapy agent, a cell therapy agent, a gene therapy agent, a hormone therapy agent, an antiviral agent, an antibiotic, an analgesic, an antioxidant, a metal chelator, a cytokine, an activator, an imaging agent, a cytotoxic agent, an angiogenesis inhibitor, a kinase inhibitor, a costimulatory molecule agonist, a co-inhibitory molecule blocker, an adhesion molecule blocker, an anti-cytokine antibody or a functional fragment thereof, a detectable label or reporter, an antibacterial agent, a gene editing agent, a beta agonist, a viral RNA inhibitor, a polymerase inhibitor, an interferon, or a microRNA.

[0313] The term "immunotherapy," as used herein, refers to a type of therapy that stimulates or generally strengthens the immune system to fight diseases such as cancer. Examples of immunotherapies include, without limitation, checkpoint regulators, adoptive cell transfer, cytokines, oncolytic viruses, and therapeutic vaccines.

[0314] "Targeted therapy" is a type of therapy that acts on specific molecules associated with cancer, such as specific proteins that are present in cancer cells but not in normal cells, or that are abundant in cancer cells, or target molecules in the cancer microenvironment that contribute to the growth and survival of the cancer. Targeted therapy targets the therapeutic agent to the tumor, thereby protecting normal tissue from the effects of the therapeutic agent.

[0315] In some of these embodiments, an antibody or antigen-binding fragment thereof provided herein, a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein that is administered in combination with one or more additional therapeutic agents may be administered simultaneously with the one or more additional therapeutic agents; in some of these embodiments, an antibody or antigen-binding fragment thereof provided herein and / or a pharmaceutical composition provided herein and the additional therapeutic agent(s) may be administered as part of the same pharmaceutical composition. However, an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein that is administered "in combination" with another therapeutic agent is not necessarily administered simultaneously with or in the same composition as that agent. An antibody or antigen-binding fragment thereof, a chimeric antigen receptor, or a pharmaceutical composition administered before or after another agent is considered to be administered "in combination" with that agent, as that term is used herein, even if the antibody or antigen-binding fragment, pharmaceutical composition, or chimeric antigen receptor and the second agent are administered via different routes. When possible, additional therapeutic agents administered in combination with the antibody or antigen-binding fragment thereof, chimeric antigen receptor, or pharmaceutical composition disclosed herein will be administered according to the schedule listed in the product information sheet of the additional therapeutic agent or in accordance with the schedule listed in the Physicians' Desk Reference 2003 (Physicians' Desk Reference, 57 th Ed; Medical Economics Company; ISBN: 1563634457; 57 th edition (November 2002)) or according to protocols well known in the art.

[0316] The present disclosure further provides a method for inactivating LILRB2-expressing cells in vivo or in vitro, the method comprising contacting the LILRB2-expressing cells with an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein.

[0317] The present disclosure further provides a method for modulating LILRB2 activity in a LILRB2-expressing cell, the method comprising exposing the LILRB2-expressing cell to an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein. In some embodiments, the LILRB2-expressing cell is a hematopoietic stem cell, dendritic cell, monocyte, macrophage, B cell, Treg, neutrophil, basophil, platelet, progenitor mast cell, endothelial cell, neuron, or osteoclast.

[0318] In another aspect, the present disclosure provides a method of inducing or enhancing phagocytosis of a target cell in vivo or in vitro, comprising exposing the target cell to an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein.

[0319] In some embodiments, the target cell is an antigen-presenting cell, a cancer cell, or a cell infected with a pathogen. In some embodiments, the antibody or antigen-binding fragment thereof capable of inducing or enhancing phagocytosis of a target cell is an antibody or antigen-binding fragment thereof capable of binding to LILRB1 and LILRB2.

[0320] In another aspect, the present disclosure provides a method for enhancing anti-CD47 agent-mediated phagocytosis of a target cell, comprising exposing the target cell to an antibody or antigen-binding fragment thereof and / or a chimeric antigen receptor and / or a pharmaceutical composition provided herein. In some embodiments, the target cell is an antigen-presenting cell, a cancer cell, or a cell infected with a pathogen. In some embodiments, the anti-CD47 agent is an anti-CD47 antibody or antigen-binding fragment thereof.

[0321] In another aspect, the present disclosure provides use of an antibody or antigen-binding fragment thereof, chimeric antigen receptor, or pharmaceutical composition provided herein in combination with an anti-CD47 agent to induce or enhance phagocytosis of a target cell. In some embodiments, the target cell is an antigen-presenting cell, a cancer cell, or a cell infected with a pathogen. In some embodiments, the anti-CD47 agent is an anti-CD47 antibody or antigen-binding fragment thereof.

[0322] In another aspect, the present disclosure provides a kit useful for inducing or enhancing phagocytosis of target cells, comprising (a) an antibody or antigen-binding fragment thereof and / or a chimeric antigen receptor and / or a pharmaceutical composition, and (b) an anti-CD47 agent. In some embodiments, the target cells are antigen-presenting cells, cancer cells, or cells infected with a pathogen. In some embodiments, the anti-CD47 agent is an anti-CD47 antibody or antigen-binding fragment thereof.

[0323] The anti-CD47 agent can be any molecule that targets and / or binds to CD47 (e.g., human CD47). In some embodiments, the anti-CD47 agent is an anti-CD47 antibody or an antigen-binding fragment thereof. As is known in the art, anti-CD47 antibodies can enable macrophage phagocytosis of cancer cells (Diane Tseng et al., Proc Natl Acad Sci USA 2013 Jul 2; 110(27):11103-8). Various anti-CD47 antibodies have been developed in the art. In some embodiments, the anti-CD47 agent is antibody 5F9 from Forty Seven Inc. In some embodiments, the amino acid sequences of the VH, VL, HCDR, and LCDR of antibody 5F9 are shown in Table 5 below.

[0324] [Table 6]

[0325] In another aspect, the present disclosure provides a method for blocking the interaction between LILRB2 and its ligand, the method comprising exposing LILRB2 to an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition provided herein. Various ligands for LILRB2 are known in the art, such as human leukocyte antigen class I (HLA-I), HLA-F, HLA-G, CD1d, ANGPTL, Aβ oligomers, and myelin inhibitors. In some embodiments, the ligand is HLA-G. In some embodiments, LILRB2 is expressed in or on a cell. In some embodiments, the cell is selected from a hematopoietic stem cell, a dendritic cell, a monocyte, a macrophage, a neutrophil, a basophil, a platelet, a T cell, a B cell, a Treg, a precursor mast cell, an endothelial cell, a neuron, or an osteoclast.

[0326] In another aspect, the present disclosure provides a method for inhibiting M2-like polarization of immature macrophages, comprising exposing the immature macrophages to an antibody or antigen-binding fragment thereof and / or chimeric antigen receptor and / or pharmaceutical composition provided herein. Activated macrophages can be divided into two types: M1-like macrophages and M2-like macrophages, both of which are involved in inflammatory responses. M2-like polarized tumor-associated macrophages play an important role in promoting cancer cell growth, invasion, metastasis, and angiogenesis. Therefore, M2-like polarization of immature macrophages is usually undesirable. In some embodiments, the purpose of inhibiting M2-like polarization of immature macrophages is to rescue T cell activation.

[0327] In another aspect, the present disclosure provides a method of inducing TNF-α production and / or CD86 expression, the method comprising exposing immature macrophages to an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein.

[0328] In another aspect, the present disclosure provides a method for detecting the presence or amount of LILRB2 in a sample, the method comprising contacting the sample with an antibody or antigen-binding fragment thereof provided herein, and / or a chimeric antigen receptor provided herein, and / or a pharmaceutical composition provided herein, and determining the presence or amount of LILRB2 in the sample.

[0329] In another aspect, the present disclosure provides a method for diagnosing a LILRB2-related disease, disorder, or condition in a subject, the method comprising: a) contacting a sample collected from the subject with an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein; b) determining the presence or amount of LILRB2 in the sample; and c) correlating the presence or amount of LILRB2 with the presence or status of a LILRB2-related disease, disorder, or condition in the subject.

[0330] In another aspect, the present disclosure provides a kit comprising an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein, optionally conjugated to a detectable moiety useful for detecting LILRB2, optionally recombinant LILRB2, cell surface-expressed LILRB2, or LILRB2-expressing cells. The kit may further comprise instructions for use.

[0331] In another aspect, the present disclosure also provides use of an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein in the manufacture of a medicament for treating, preventing, or ameliorating a LILRB2-related disease, disorder, or condition in a subject.

[0332] In another aspect, the present disclosure also provides use of an antibody or antigen-binding fragment thereof provided herein and / or a chimeric antigen receptor provided herein and / or a pharmaceutical composition provided herein in the manufacture of a diagnostic reagent for diagnosing a LILRB2-related disease, disorder, or condition.

[0333] The following examples are provided to better illustrate the present invention and should not be construed as limiting the scope of the present invention. All specific compositions, materials, and methods described below are within the scope of the present invention, in whole or in part. These specific compositions, materials, and methods are not intended to limit the present invention, but are merely intended to illustrate specific embodiments within the scope of the present invention. Those skilled in the art will be able to develop equivalent compositions, materials, and methods without creative effort and without departing from the scope of the present invention. It will be understood that many variations can be made to the procedures described herein within the scope of the present invention. It is the intention of the inventors that such variations are included within the scope of the present invention. [Example]

[0334] Example 1 Antibody production 1.1 Immunization

[0335] To generate antibodies targeting LILRB2 that may also have potential cross-reactivity to LILRB1, Balb / c and CD1 mice were immunized in groups with human LILRB2-overexpressing cells (CHO-S-hLILRB2) or recombinant human LILRB2 protein (complete extracellular domain, or domains 1 and 2), and human LILRB1 cells (CHO-S-hLILRB1) or recombinant human LILRB1 protein (complete extracellular domain) (as shown in Table 6 below). The immunogen was delivered to the mice by intrahepatic (IH) and / or intraperitoneal (IP) injection. After the initial immunization, several boosts were administered until the animals developed antiserum titers suitable for hybridoma development. Complete Freund's adjuvant (CFA) was used for the initial immunization, and incomplete Freund's adjuvant (IFA) was used for subsequent immunizations. The immunization protocols for animals in each group are shown in Tables 7, 8, and 9 below.

[0336] [Table 7]

[0337] [Table 8]

[0338] [Table 9]

[0339] [Table 10] 1.2 Hybridoma generation and screening

[0340] Spleen cell fusion was performed on mice determined to respond best to immunization by test bleed FACS and ELISA. FACS assays were performed on CHO-S or HEK293T cell lines stably overexpressing human LILRB2 or LILRB1 (i.e., CHO-S-hLILRB2, CHO-S-hLILRB1, HEK293T-hLILRB2, or HEK293T-hLILRB1). For ELISA assays, the complete extracellular domain of recombinant human LILRB2 protein was coated as a ligand to test antiserum concentrations. Lymphocytes from the spleen and lymph nodes were fused with a mouse myeloma cell line (SP2 / 0) using an optimized electrofusion protocol. Multiple fusions were performed to ensure the success of the project.

[0341] Fusions were plated in stacks of 96-well plates (2 × 10 4 ~10 5 Cells were grown in 24-well plates. Growth was monitored and replenished weekly. Cells were screened within 10–14 days using primary screening assays, FACS and ELISA. Multiple fusions were performed for each target antigen and screened. Positive parental clones (with or without positive binding to CHO-S-hLILRB1, domains 1 and 2 of recombinant human LILRB2 protein, or domains 1 and 2 of recombinant human LILRB1 protein) that showed positive binding to the extracellular domains of recombinant human LILRB2 and CHO-S-hLILRB2 were expanded into 24-well plates for secondary screening.

[0342] After the primary screening, positive parental clones grown in 24-well plates were screened again by the assays described below in FACS or ELISA assays. Hybridomas of interest were selected and proceeded to subcloning.

[0343] Parental hybridomas with the desired reactivity and isotype from the above screening funnel were then subcloned by multiple rounds of limiting dilution or single cell sorting until monoclones were obtained.

[0344] Subcloning plates were screened by protein-based ELISA (recombinant human LILRB2 extracellular domain), and subclones with good binding ability were expanded to 24 wells for confirmation testing. The specificity and cross-reactivity of these subclones were confirmed by FACS analysis. Briefly, parental HEK293T or HEK293F cells, HEK293F-hLILRB2, HEK293T-hLILRB1, HEK293T-hLILRB3, HEK293F-hLILRB4, HEK293T-hLILRB5, HEK293T-hLILRA1, HEK293T-hLILRA2, HEK293T-hLILRA3, HEK293T-hLILRA4, and HEK293T-hLILRA5 were incubated with antibodies produced by each subclone, respectively. Binding of the primary antibody to the cells was detected using a fluorochrome-conjugated secondary antibody. Median fluorescence intensity (MFI) was determined by FACS analysis.

[0345] The desired subclonal cell lines were sequenced and further expanded in culture flasks for cryopreservation. Initially, 0.5–13.0 × 10 6 Cells were cryopreserved at 4-6 vials per cell line. Master and working cell banks were established for the selected most valuable cell lines.

[0346] As shown in Table 10, 30 antibodies with unique sequences were discovered that showed positive binding to HEK293F cells stably overexpressing human LILRB2 protein (HEK293F-hLILRB2), suggesting that these antibodies target LILRB2. Among them, 11 antibodies (i.e., 23-H3-D3-C7, 45-H2-B10-G4-F3, 18-D2-G7-G8, 24-A4-G8-C11-H3, 33-G2-C6-E3, 49-D6-G3-E1, 34-F6-H9-D1, 34-F12-G3-G12, 45-F1-F5-A2, 44-A4-B8-A4, and 50-F11-G7-F8) were also able to bind to HEK293T cells stably overexpressing human LILRB1 (HEK293T-hLILRB1). None of these antibodies showed cross-reactivity with hLILRB3, hLILRB4, hLILRB5, hLILRA1, hLILRA2, hLILRA3, hLILRA4, or hLILRA5 expressed on HEK293 cells. The binding ability of these mouse antibodies to HEK293F-hLILRB2, HEK293T-hLILRB1, HEK293T-hLILRB3, HEK293F-hLILRB4, HEK293T-hLILRB5, HEK293T-hLILRA1, HEK293T-hLILRA2, HEK293T-hLILRA3, HEK293T-hLILRA4, and HEK293T-hLILRA5 cells, as detected by FACS, is summarized in Table 10 below.

[0347] [Table 11-1] [Table 11-2]

[0348] Example 2 Antibody Characterization: Binding Affinity 2.1 Antibodies

[0349] Hybridoma antibody clones 23-H3-D3-C7, 44-D7-C12-B6, 45-H2-B10-G4-F3, 30-D2-F6-F10, 18-D2-G7-G8, 20-H7-F3-H5, 24-A4-G8-C11-H 3, 33-E3-C9-G8, 18-H4-A10-B7, 41-E2-E6-E12-E5, 47-E4-A8-A8, 40-G4-A8-G5, 33-G2-C6-E3, 34-A5-A8-D6, 49-D6-G3-E1, 41- E2-E5-C7, 34-F6-H9-D1, 34-F12-G3-G12, 45-F1-F5-A2, 38-C7-D6-G3, 12-C11-G2-H5, 19-H6-A9-E4, 14-G11-G12-C4, 33-G3-C3-D8, 17-F8-G4-C5, 44-A4-B8-A4, 7-E10-G7-E7, 30-A12-C8-F8, 50-F11-G7-F8, and 10-F12-G9-D3 were characterized and their sequences identified by the following methods. 2.2 Hybridoma sequencing

[0350] Total RNA was isolated from hybridoma cells according to the technical manual of RNAiso Plus (TAKARA Cat#9109). Then, RNA was purified using PrimeScript II 1 with isotype-specific antisense primers or universal primers. st Total RNA was reverse transcribed into cDNA according to the technical manual of the Strand cDNA Synthesis Kit (TAKARA Cat# 6210A). VH and VL antibody fragments were amplified according to TaKaRa Taq™ (Cat# R001A). The amplified antibody fragments were individually cloned into standard cloning vectors. Colony PCR was performed to screen for clones with inserts of the correct size. For each fragment, five or more colonies with inserts of the correct size were sequenced. The sequences of different clones were aligned to provide a consensus sequence for these clones.

[0351] The CDR and variable region sequences of the hybridoma antibodies are shown in Tables 2 and 3 herein above. 2.3 Chimeric antibody generation

[0352] To evaluate the binding affinity of antibody candidates to hLILRB2 in cell-based assays, the sequences of 30 mouse antibodies in Table 10 were selected to generate and produce human IgG4 chimeric antibodies. Two reference antibodies (i.e., J-19.h1 and 1E1) were also generated as human IgG4 chimeric antibodies. Generally, DNA encoding the variable regions of the 30 mouse antibodies was synthesized and subcloned into an expression vector pre-loaded with a human IgG4 constant gene (containing the S228P mutation according to EU numbering). The vector was transfected into mammalian cells for recombinant protein expression, and the expressed antibodies were purified using a protein A affinity chromatography column. The resulting chimeric antibodies are referred to herein as ch23-H3-D3-C7, ch44-D7-C12-B6, ch45-H2-B10-G4-F3, ch30-D2-F6-F10, ch18-D2-G7-G8, ch20-H7-F3-H5, ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch18-H4-A10-B7, ch41-E2-E6-E12-E5, ch47-E4-A8-A8, ch40-G4-A8-G5, ch33-G2-C6-E3, ch34-A5-A8-D6, ch49-D6-G3-E1, ch41-E2-E5-C7, ch3 ch44-A4-B8-A4, ch7-E10-G7-E7, ch30-A12-C8-F8, ch50-F11-G7-F8, and ch10-F12-G9-D3, where the prefix "ch" indicates "chimeric" followed by the hybridoma antibody clone. For example, ch23-H3-D3-C7 indicates a chimeric antibody derived from hybridoma antibody clone 23-H3-D3-C7. The two reference antibodies generated as human IgG4 chimeric antibodies are still designated J-19.h1 and 1E1, respectively. 2.4 Antibody binding affinity to HEK293F cells stably overexpressing human LILRB2 (i.e., HEK293F-hLILRB2)

[0353] The binding affinities of these chimeric antibodies and reference antibodies (J-19.h1 and 1E1) to HEK293F cells stably overexpressing human LILRB2 protein (ie, HEK293F-hLILRB2) were determined by FACS analysis.

[0354] The protocol for FACS analysis is described below. (a) Cells were collected by centrifugation at 300 g for 5 minutes and the supernatant was discarded. (b) Cells were washed twice with FACS buffer by centrifugation at 300 g for 5 minutes and the supernatant was discarded. (c) Resuspend the cells and plate them at 1 x 10 cells onto the assay plate in 50 μl of FACS buffer. 5 Cells were seeded at 1000 x g / well. 50 μl of primary antibody at a concentration series (final concentrations: 200,000 nM, 66,667 nM, 22,222 nM, 7,407 nM, 2.469 nM, 0.823 nM, 0.274 nM, 0.091 nM, 0.030 nM, 0.010 nM, 0.003 nM, 0.000 nM) was added to each well and incubated with the cells in a CO2 incubator for 1 hour. (d) Step (b) was repeated and the cells were resuspended in 100 μl / well of diluted secondary antibody (PE-conjugated anti-human IgG Fc) and incubated at 4° C. in the dark for 45 minutes. (e) Step (b) was repeated and the cells were resuspended in 150 μl / well of FACS buffer. The cells were stored in the dark for FACS analysis.

[0355] As shown in Table 11 and Figures 1 and 2, the binding affinity of some selected antibodies to HEK293F-hLILRB2 cells was higher than or comparable to that of the reference antibodies J-19.h1 and 1E1.

[0356] [Table 12] 2.5 Antibody binding affinity to HEK293T cells stably overexpressing human LILRB1 (i.e., HEK293T-hLILRB1)

[0357] To evaluate the binding affinity of antibody candidates to hLILRB1 in a cell-based assay, the binding affinities of the chimeric antibody produced in Example 2.3 and the reference antibody 15G8 (a known anti-LILRB1 antibody produced as a human IgG4 chimeric antibody) to HEK293T cells stably overexpressing human LILRB1 protein were determined by FACS analysis. The antibody concentrations were 100.000 nM, 33.333 nM, 11.111 nM, 3.704 nM, 1.235 nM, 0.412 nM, 0.137 nM, 0.046 nM, and 0.000 nM.

[0358] As shown in Table 12 and Figure 3, the binding affinities of some selected antibodies (ch23-H3-D3-C7, ch34-F6-H9-D1, ch34-F12-G3-G12, ch44-A4-B8-A4, and ch50-F11-G7-F8) to HEK293T-hLILRB1 cells were comparable to that of the reference antibody 15G8. 2.6 Cross-reactivity to HEK293T cells stably overexpressing mouse LILRB2 and monkey LILRB2 (i.e., HEK293T-mouse LILRB2 and HEK293T-monkey LILRB2)

[0359] The binding affinities of the chimeric antibodies generated in Example 2.3 and the reference antibodies (J-19.h1 and 1E1) to HEK293T cells stably overexpressing mouse LILRB2 (Mus musculus paired Ig-like receptor B (Pirb), NM_011095.2) or monkey LILRB2 (rhesus monkey LILRBb (putative), Q1I0P6_MACMU) were determined by FACS analysis. As shown in Table 12 and Figure 4, none of the antibodies showed cross-reactivity to mouse LILRB2, and two selected antibodies (i.e., ch19-H6-A9-E4 and ch50-F11-G7-F8) showed cross-reactivity to monkey LILRB2.

[0360] [Table 13-1] [Table 13-2] 2.7 Antibody binding affinity testing using surface plasmon resonance (SPR)

[0361] The binding affinities of the chimeric antibody produced in Example 2.3 and the reference antibody B2-19 to HIS-tagged human LILRB2 (hLILRB2-HIS) were determined using Biacore™ 8K (Cytiva). The test conditions were as follows: ● Capture ligand: 2 μg / Ml antibody in running buffer, 10 mL / min, approximately 300-450 RU capture; ● Running buffer: HBS-EP+ buffer, ● Association and dissociation flow rate: 30 mL / min, 120 s association and 300 s dissociation, ● Regeneration buffer: 10mM pH1.5 Gly-HCL, ● Regeneration flow rate: 30mL / min, 30s, ● Analysis temperature: 25℃.

[0362] As shown in Table 13, the binding affinities of some chimeric antibodies (ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch47-E4-A8-A8, ch40-G4-A8-G5, ch34-A5-A8-D6, ch34-F12-G3-G12, ch19-H6-A9-E4, ch45-F1-F5-A2) were comparable to or higher than the reference antibody B2-19.

[0363] [Table 14-1] [Table 14-2]

[0364] Example 3 Antibody Characterization: Functional Blocking Capacity

[0365] To determine the functional blocking ability of selected antibodies, we employed a reporter system to screen LILRB2 or LILRB1 blocking antibodies using stable chimeric receptor reporter cells (i.e., Jurkat-hLILRB2 ECD-PILRβ TM-PILRβ ICD-DAP12-NFAT-Luc cells and Jurkat-hLILRB1 ECD-PILRβ TM-PILRβ ICD-DAP12-NFAT-Luc cells). This reporter system could test the ability of ligands (e.g., HLA-G) to bind to the extracellular domain of LILRB2 or LILRB1. This reporter system could also report signaling activation or inhibition of the chemically fused intracellular domain of the paired immunoglobulin-like receptor (PILR) β. The luciferase (Luc) reporter gene was driven by the NFAT promoter, which is activated via the adaptor DAP-12 signaling pathway. Activation of chimeric signaling by binding of agonist antibodies to the ECD could be reported as increased luciferase expression, whereas inhibition of chimeric signaling by binding of antagonist antibodies to the ECD could be reported as decreased Luc expression.

[0366] In this assay, 0.5 × 10 5 Chimeric receptor reporter cells were seeded at 0.5 × 10 per well in a U-bottom 96-well plate and incubated with the selected antibody for 1 hour in a CO2 incubator. After antibody incubation, 0.5 × 10 cells were 5 K562-HLA-G cells (i.e., K562 cells stably overexpressing HLA-G) were added at 1000p / well and incubated for 24 hours. Cells were harvested and Luc expression levels were assessed using the Luciferase Assay System (Promega #E4530).

[0367] As shown in Figure 5 , 18 antibodies (i.e., ch23-H3-D3-C7, ch30-D2-F6-F10, ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch47-E4-A8-A8, ch40-G4-A8-G5, ch33-G2-C6-E3, ch34-A5-A8-D6, ch49-D6-G3-E1, ch34-F6 -H9-D1, ch34-F12-G3-G12, ch45-F1-F5-A2, ch19-H6-A9-E4, ch33-G3-C3-D8, ch17-F8-G4-C5, ch30-A12-C8-F8, ch50-F11-G7-F8, and ch10-F12-G9-D3) showed potent blocking activity of HLA-G / LILRB2 interaction. Some of these antibodies (e.g., ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch34-F6-H9-D1, ch45-F1-F5-A2, ch30-A12-C8-F8, ch50-F11-G7-F8, ch10-F12-G9-D3) showed comparable blocking activity compared to the reference antibodies J-19.h1 and 1E1, indicating complete blockade of the HLA-G / LILRB2 interaction.

[0368] As shown in Figure 9, three antibodies (i.e., ch23-H3-D3-C7, ch34-F6-H9-D1, and ch50-F11-G7-F8) showed potent blocking activity of HLA-G / LILRB1 interaction. Some of these antibodies (e.g., ch34-F6-H9-D1 and ch50-F11-G7-F8) showed comparable blocking activity compared to the reference antibody Hz73D1.v1, indicating complete blocking of HLA-G / LILRB1 interaction.

[0369] Another NFAT-Luc reporter cell-based assay was used to assess the blocking ability of selected antibodies to relieve HLA-G-mediated inhibition via LILRB2 or LILRB1. Jurkat NFAT reporter cells were engineered to stably express full-length human LILRB2 or human LILRB1. In this assay, anti-CD3 antibody (clone OKT3) was coated at 1 μg / ml onto U-bottom 96-well plates. 0.66 × 10 5 / well chimeric receptor cells and 0.33 x 10 5 K562-HLA-G cells (or RPMI-8226 cells expressing HLA-A, B, and C) were seeded in a U-bottom 96-well plate at 1 / well and incubated with the selected antibodies for 24 hours in a CO2 incubator. The cells were harvested, and Luc expression levels were assessed using the Luciferase Assay System.

[0370] As shown in Figure 10, some antibodies (e.g., ch30-D2-F6-F10, ch33-E3-C9-G8, ch45-F1-F5-A2, ch30-A12-C8-F8, ch19-H6-A9-E4) showed comparable blocking activity compared to the reference antibodies B2-19 and 1E1, indicating complete blockade of the HLA-G / LILRB2 interaction or the HLA-A, B, C / LILRB2 interaction. As shown in Figure 11, ch34-F6-H9-D1 showed comparable blocking activity compared to the reference antibody 15G8, indicating complete blockade of the HLA-G / LILRB1 interaction.

[0371] Example 4 Antibody Characterization: Polarization of Macrophages to a More Inflammatory Phenotype 4.1 Anti-LILRB2 antibody-enhanced LPS-induced inflammatory response in immature macrophages

[0372] To determine whether the chimeric antibody produced in Example 2.3 can enhance inflammatory responses in immature macrophages, monocytes were isolated from peripheral blood mononuclear cells (PBMCs) of healthy donors using a human monocyte enrichment kit (Stemcell #19059) and incubated for 5 days in the presence of M-CSF (50 ng / ml, R&D Systems #216-MC-025). After 5 days of culture, immature macrophages were harvested and further stimulated with lipopolysaccharide (LPS, 50 ng / ml, Sigma #L2880) in the presence of the antibody for 3 days. Supernatants were collected, and TNF-α production was determined using a human TNF ELISA kit (BD Bioscience #555212). Cells were harvested, and CD86 expression was determined by flow cytometry.

[0373] As shown in Figures 6 and 12, all of the tested chimeric antibodies enhanced TNF-α secretion and CD86 expression in immature macrophages stimulated with LPS. 4.2 Effect of anti-LILRB2 antibodies on bone marrow-derived cytokine secretion by primary human PBMCs

[0374] To evaluate whether the chimeric anti-LILRB2 antibodies generated in Example 2.3 enhance T cell or myeloid cell inflammatory cytokine secretion, PBMCs from healthy donors were treated with 30 ng / ml LPS or 10 ng / ml anti-CD3 antibody (Clone OKT3) in the presence of the selected antibodies. Supernatants were collected, and TNF-α and GM-CSF production were determined using a human TNF ELISA kit and a human GM-CSF ELISA kit (BD Bioscience #555126). As shown in Figure 13, all tested chimeric antibodies enhanced LPS-stimulated GM-CSF secretion and anti-CD3 antibody-stimulated TNF-α secretion. 4.3 Inhibitory effect of anti-LILRB2 antibodies on the polarization of monocytes toward a macrophage-like immunosuppressive phenotype

[0375] To determine whether the chimeric anti-LILRB2 antibodies generated in Example 2.3 could inhibit the polarization of monocytes toward a macrophage-like immunosuppressive phenotype, monocytes were incubated in the presence of M-CSF (50 ng / ml) and selected antibodies for 5 days (Figure 14A), or immature macrophages derived from monocytes were incubated in the presence of TGF-β (20 ng / ml, R&D Systems #204-IL-050), IL-10 (20 ng / ml, R&D Systems #217-IL-025), and selected antibodies for 3 days (Figure 14B). After incubation, cells were harvested, and CD163 and CD206 expression was determined by flow cytometry. As shown in Figure 14, all tested chimeric antibodies reduced the expression of CD163 and CD206, which are representative markers of anti-inflammatory macrophages. Some antibodies (e.g., ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch45-F1-F5-A2, ch19-H6-A9-E4) had higher or similar activity in suppressing M2-like polarization of macrophages compared to the reference antibodies J-19.h1 and B2-19. 4.4 Inhibition of M2-like polarization of immature macrophages by anti-LILRB2 antibodies to rescue T cell activation

[0376] To determine whether the chimeric antibodies generated in Example 2.3 can suppress M2-like polarization of immature macrophages to rescue T cell activation, monocytes were isolated from PBMCs of healthy donors, cultured with M-CSF (50 ng / ml) for 5 days, and then polarized into anti-inflammatory macrophages for 24 hours in the presence of selected antibodies using IL-4 (20 ng / ml, R&D Systems #204-IL-050) and IL-10 (20 ng / ml, R&D Systems #217-IL-025). Allogeneic T cells were isolated from PBMCs of healthy donors using a human T cell enrichment kit (Stemcell #19051) and then co-cultured with macrophages (1 x 10 cells in U-bottom 96-well plates) for 4 days in the presence of selected antibodies, CD3 / CD28 Dynabeads activator (Gibco #11131D). 5 T cells / well, T cells:macrophages = 4:1, T cells:beads = 10:1). T cells were collected to determine activation (CD25 expression as a marker assessed by flow cytometry).

[0377] As shown in Figure 7, all chimeric antibodies reversed macrophage-mediated suppression of T cell activation, and some antibodies (e.g., ch45-H2-B10-G4-F3, ch30-D2-F6-F10, ch24-A4-G8-C11-H3, ch33-E3-C9-G8, ch34-A5-A8-D6, ch45-F1-F5-A2, ch33-G3-C3-D8, ch17-F8-G4-C5, ch30-A12-C8-F8, ch50-F11-G7-F8, ch10-F12-G9-D3) had higher or similar suppressive activity of M2-like polarization of macrophages to rescue T cell activation compared to the reference antibodies J-19.h1 and 1E1.

[0378] Additionally, monocytes were isolated from PBMCs of healthy donors and cultured with M-CSF for 5 days, followed by polarization into anti-inflammatory macrophages using TGF-β and IL-10. Autologous T cells were isolated from PBMCs of the same donors using a human T cell enrichment kit (Stemcell #19051) and then cocultured with macrophages pretreated with selected antibodies for 24 hours in the presence of 10 ng / ml CD3 antibody (Clone OKT3) and selected antibodies for 60 hours. Supernatants were collected to assess activation (IFN-γ production).

[0379] As shown in Figure 15, all tested chimeric antibodies reversed macrophage-mediated suppression of T cell activation, and some antibodies (e.g., ch19-H6-A9-E4, ch45-F1-F5-A2, ch24-A4-G8-C11-H3, ch33-E3-C9-G8) had higher or similar suppressive activity of M2-like polarization of macrophages to rescue T cell activation compared to the reference antibodies J-19.h1, B2-19, and 1E1. 4.5 Anti-LILRB2 antibody relieved T cells from MDSC-mediated immunosuppression

[0380] To generate monocytic myeloid-derived suppressor cells (M-MDSCs) derived from cancer cell lines, healthy human PBMCs from individual donors were cultured with SK-MEL-5 tumor cells at a ratio of 50:1 (PBMCs:SK-MEL-5) in cell culture medium in the presence of 20 ng / mL GM-CSF (R&D Systems #215-GM-050) for 7 days. Autologous T cells were isolated from the healthy donor's PBMCs using a human T cell enrichment kit and then cocultured with CD33+ M-MDSCs isolated using a human CD33 Positive Selection Kit (Stemcell #17876) at a ratio of 4:1 (T cells:MDSCs) in the presence of CD3 / CD28 Dynabeads activator (Gibco #11131D), 100 U / mL IL-2 (R&D Systems #BT-002-050), and selected antibodies for 4 days. Supernatants were collected to assess IFN-γ production.

[0381] As shown in Figure 16, all tested chimeric antibodies reversed MDSC-mediated suppression of T cell activation, with some antibodies (e.g., ch30-D2-F6-F10, ch19-H6-A9-E4, ch45-F1-F5-A2, ch33-E3-C9-G8, ch30-A12-C8-F8) having greater or similar activity in rescuing T cell activation from suppression by MDSC compared to the reference antibodies J-19.h1 and B2-19.

[0382] Example 5 Antibody Characterization: Anti-CD47-Mediated Phagocytosis Enhancement

[0383] To evaluate the ability of selected antibodies to enhance anti-CD47-mediated phagocytosis, monocytes were isolated from PBMCs of healthy donors and cultured with M-CSF (50 ng / ml) for 5 days. They were then polarized into anti-inflammatory macrophages with TGF-β (20 ng / ml, R&D Systems #240-B-010) and IL-10 (20 ng / ml) for 3 days. Human melanoma cancer cells A375 stably expressing HLA-G (i.e., A375-HLA-G) were labeled with 1 μM CFSE (Thermo Fisher Scientific #C34554) at 10 million cells / mL for 20 minutes at 37°C. They were then pretreated for 30 minutes with selected anti-LILRB2 antibodies (cross-reactive with LILRB1) and reference antibodies (15G8 and Hz73D1.v1, known anti-LILRB1 antibodies also produced as human IgG4 chimeric antibodies). Mature macrophages were added at a 1:1 ratio (effector:target) in the presence of 5 nM anti-CD47 antibody (Clone 5F9, Forty Seven Inc.) and co-cultured for 2 hours. Macrophages and A375-HLA-G cells were collected and stained with APC-conjugated anti-human CD14 antibody (Biolegend #367118). Macrophage-mediated phagocytosis was examined by FACS analysis.

[0384] As shown in Figure 8, all tested chimeric antibodies enhanced anti-CD47-mediated macrophage phagocytosis.

[0385] Example 6. Combination of anti-LILRB2 and anti-PD-(L)1 antibodies rescues T cell activity from suppression by immunosuppressive myeloid cells

[0386] To determine whether the combination of an anti-LILRB2 antibody and a PD-L1 antibody (atezolizumab) could enhance T cell activation in a mixed lymphocyte reaction (MLR), monocytes were isolated from PBMCs of healthy donors, cultured with M-CSF for 5 days, and polarized into anti-inflammatory macrophages with TGF-β and IL-10. Autologous T cells were isolated from the same donor's PBMCs using a human T cell enrichment kit and then co-cultured with macrophages for 48 hours in the presence of 10 ng / ml of CD3 antibody (Clone OKT3), PD-L1 antibody, and the selected chimeric anti-LILRB2 antibody. Supernatants were collected to assess IFN-γ production.

[0387] As shown in Figure 17, chimeric anti-LILRB2 antibodies (e.g., ch19-H6-A9-E4, ch45-F1-F5-A2, ch33-E3-C9-G8) were more active in suppressing M2-like polarization of macrophages to rescue T cell activation compared to the reference antibody B2-19, and enhanced T cell activation in combination with PD-L1 antibodies.

[0388] Example 7 Anti-LILRB2 antibodies showed potent anti-tumor activity in a syngeneic Lewis lung carcinoma (LLC1) model in LILRB2 transgenic mice

[0389] The antitumor efficacy of anti-LILRB2 antibodies was evaluated in LILRB2 transgenic C57BL / 6 mice bearing syngeneic murine Lewis lung carcinoma (LLC1) tumor cells. 5 Mice were subcutaneously injected with IgG4 isotype (cells). Five days after injection, groups of eight female animals were randomized to receive 10 mg / kg of IgG4 isotype, 10 mg / kg of ch45-F1-F5-A2, 6 mg / kg of ch45-F1-F5-A2, 3 mg / kg of ch45-F1-F5-A2, or 10 mg / kg of reference antibody B2-19 intraperitoneally, BIW, for up to 21 days. Tumor volume was measured twice weekly in two dimensions using calipers and calculated in mm using the formula V = (L × W × W) / 2.3 where V is tumor volume, L is tumor length (the longest dimension of the tumor), and W is tumor width (the longest dimension of the tumor perpendicular to L). No obvious weight loss or toxic effects were observed in any treatment group. As shown in Figure 18, ch45-F1-F5-A2 exhibited antitumor activity in the LLC1 model at 10 mg / kg and 6 mg / kg compared to the IgG4 isotype control group, with TGI values ​​of 43.32% and 34.88%, respectively, on day 21.

[0390] Example 8 Anti-LILRB2 antibodies showed potent anti-tumor activity in the humanized mouse breast cancer MDA-MB-231 model

[0391] The anti-tumor activity of anti-LILRB2 antibodies was tested in a humanized mouse MDA-MB-231 model. To generate macrophages, monocytes were isolated from PBMCs of healthy donors and cultured with 100 ng / ml M-CSF for 6 days. Macrophages (2 × 10 5 cells), PBMC (4 × 10 5 cells) and MDA-MB-231 cells (1 × 10 7 The tumor volume was approximately 80 mm. 3 When the tumor size reached 100 mg / kg, female animals were randomized into groups of 6 to receive 10 mg / kg of the IgG4 isotype, ch45-F1-F5-A2, or ch33-E3-C9-G8 intraperitoneally Q3D. No significant weight loss or toxic effects were observed in any of the treatment groups. As shown in Figure 19, ch45-F1-F5-A2 demonstrated antitumor activity in the MDA-MB-231 model at 10 mg / kg compared to the IgG4 isotype control group, with a TGI value of 25.69% on day 11 post-injection.

[0392] Example 9 Epitope Binding of Anti-LILRB2 Antibodies

[0393] To determine whether anti-LILRB2 antibodies competitively bind with reference antibodies (B2-19 and J-19.h1), the reference antibodies were conjugated with APC using an APC labeling kit (Abcam #ab201807). HEK293F-hLILRB2 cells were seeded into a 96-well plate in the presence of 10 nM APC-conjugated B2-19 or J-19.h1 and a range of concentrations of the chimeric anti-LILRB2 antibodies produced in Example 2.3, and incubated at 4°C in the dark for 1 hour. To determine whether ch45-F1-F5-A2 competitively binds with ch19-H6-A9-E4, ch45-F1-F5-A2 and ch19-H6-A9-E4 were conjugated with PE using a PE labeling kit (Abcam #ab102918). HEK293F-hLILRB2 cells were seeded in 96-well plates in the presence of 6.67 nM PE-conjugated ch45-F1-F5-A2 or ch19-H6-A9-E4 and a range of concentrations of chimeric anti-LILRB2 antibodies (ch19-H6-A9-E4 or ch45-F1-F5-A2). Competitive binding activity was measured by FACS analysis.

[0394] As shown in Figure 20A, chimeric antibodies (e.g., ch24-A4-G8-C11-H3, ch47-E4-A8-A8, ch40-G4-A8-G5, ch45-F1-F5-A2, ch19-H6-A9-E4, ch33-G3-C3-D8, ch10-F12-G9-D3) exhibited binding epitopes on LILRB2 that were different from those of the reference antibody B2-19. As shown in Figure 20B, chimeric antibodies (e.g., ch24-A4-G8-C11-H3, ch47-E4-A8-A8, ch40-G4-A8-G5, ch45-F1-F5-A2, ch19-H6-A9-E4, ch33-G3-C3-D8, ch10-F12-G9-D3, ch30-D2-F6-F10, and ch30-A12-C8-F8) exhibited binding epitopes on LILRB2 that were different from those of the reference antibody J-19.h1. In addition, ch45-F1-F5-A2 recognized a different epitope on LILRB2 compared to ch19-H6-A9-E4 (Figure 20C).

Claims

1. An antibody or antigen-binding fragment thereof that binds to LILRB2, one, two or three heavy chain complementarity determining regions (HCDR1, HCDR2 and / or HCDR3) contained within any one of the heavy chain variable (VH) region sequences selected from the group consisting of SEQ ID NOs: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231 and 239; and / or one, two or three light chain complementarity determining regions (LCDR1, LCDR2 and / or LCDR3) contained within any one of the light chain variable (VL) region sequences selected from the group consisting of SEQ ID NOs: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232 and 240; An antibody or antigen-binding fragment thereof comprising:

2. The antibodies or antigen-binding fragments may be selected from the group consisting of SEQ ID NOs: 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 22, 25, 26, 27, 28, 29, 30, 33, 34, 35, 36, 37, 38, 41, 42, 43, 44, 45, 46, 49, 50, 51, 52, 53, 54, 57, 58, 59, 60, 61, 62, 65, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 78, 81, 82, 83, 84, 85, 86, 89, 90, 91, 92, 93, 94, 97, 98, 99, 100, 101, 102, 105, 106, 107, 108, 109, 110, 113, 114, 115, 116, 117, 118, 121, 122, 123, 124, 125, 126, 129, 130, 131, 132, 133, 134, 137, 138, 139, 140, 141, 142, 145, 146, 147, 148, 149, 150, 153, 154, 155, 156, 157, 158, 161, 162, 163, 164, 165, 166, 169, 170, 171, 172, 173, 174, 177, 178, 179, 180, 181, 182, 185, 186, 187, 188, 189, 190, 193, 194, 195, 196, 197, 198, 201, 202, 203 2. The antibody or antigen-binding fragment thereof of claim 1, comprising at least one heavy or light chain complementarity determining region (CDR) comprising an amino acid sequence selected from the group consisting of: 3, 204, 205, 206, 209, 210, 211, 212, 213, 214, 217, 218, 219, 220, 221, 222, 225, 226, 227, 228, 229, 230, 233, 234, 235, 236, 237, and 238.

3. SEQ ID NOs: 1, 2, 3, 9, 10, 11, 17, 18, 19, 25, 26, 27, 33, 34, 35, 41, 42, 43, 49, 50, 51, 57, 58, 59, 65, 66, 67, 73, 74, 75, 81, 82, 83, 89, 90, 91, 97, 98, 99, 105, 106, 107, 113, 114, 115, 121, 122, 123, 129, 130, 131, 137, 138, 139, 145, 146, 147, 153, 154, 155, 161, 162 3. The antibody or antigen-binding fragment thereof according to claim 1 or 2, comprising a VH region comprising one or two or three of HCDR1, HCDR2 and HCDR3 comprising an amino acid sequence selected from the group consisting of: 2, 163, 169, 170, 171, 177, 178, 179, 185, 186, 187, 193, 194, 195, 201, 202, 203, 209, 210, 211, 217, 218, 219, 225, 226, 227, 233, 234 and 235.

4. SEQ ID NOs: 4, 5, 6, 12, 13, 14, 20, 21, 22, 28, 29, 30, 36, 37, 38, 44, 45, 46, 52, 53, 54, 60, 61, 62, 68, 69, 70, 76, 77, 78, 84, 85, 86, 92, 93, 94, 100, 101, 102, 108, 109, 110, 116, 117, 118, 124, 125, 126, 132, 133, 134, 140, 141, 142, 148, 149, 150, 156, 157, 158, 164, 165 4. The antibody or antigen-binding fragment thereof according to any one of claims 1 to 3, comprising a VL region comprising one or two or three of LCDR1, LCDR2 and LCDR3 comprising an amino acid sequence selected from the group consisting of: 166, 172, 173, 174, 180, 181, 182, 188, 189, 190, 196, 197, 198, 204, 205, 206, 212, 213, 214, 220, 221, 222, 228, 229, 230, 236, 237 and 238.

5. i. HCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 1, 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, 97, 105, 113, 121, 129, 137, 145, 153, 161, 169, 177, 185, 193, 201, 209, 217, 225, and 233; ii. an HCDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 10, 18, 26, 34, 42, 50, 58, 66, 74, 82, 90, 98, 106, 114, 122, 130, 138, 146, 154, 162, 170, 178, 186, 194, 202, 210, 218, 226, and 234; and iii. comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227, and 235; The antibody or antigen-binding fragment thereof of any one of claims 1 to 4, comprising HCDR3.

6. i. an LCDR1 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4, 12, 20, 28, 36, 44, 52, 60, 68, 76, 84, 92, 100, 108, 116, 124, 132, 140, 148, 156, 164, 172, 180, 188, 196, 204, 212, 220, 228, and 236; ii. an LCDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 5, 13, 21, 29, 37, 45, 53, 61, 69, 77, 85, 93, 101, 109, 117, 125, 133, 141, 149, 157, 165, 173, 181, 189, 197, 205, 213, 221, 229, and 237; and iii. an LCDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 6, 14, 22, 30, 38, 46, 54, 62, 70, 78, 86, 94, 102, 110, 118, 126, 134, 142, 150, 158, 166, 174, 182, 190, 198, 206, 214, 222, 230, and 238; The antibody or antigen-binding fragment thereof of any one of claims 1 to 5, comprising:

7. i. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 2, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 3; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11; iii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 18, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 19; iv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27; v. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 34, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 35; vi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 42, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 43; vii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 50, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 51; viii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 58, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 59; ix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 66, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 67; x. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 74, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 75; xi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 82, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 83; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91; xiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 98, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 99; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115; xvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 122, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 123; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131; xviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 138, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 139; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155; xxi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 162, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 163; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219; xxix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, or xxx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 234, and HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 235; The antibody or antigen-binding fragment thereof of any one of claims 1 to 6, comprising:

8. i. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 6; ii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 14; iii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 22; iv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 30; v. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 38; vi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 46; vii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 54; viii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 62; ix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 70; x. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 78; xi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 86; xii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 102; xiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 126; xvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 142; xix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 166; xxii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 238; The antibody or antigen-binding fragment thereof of any one of claims 1 to 7, comprising:

9. i. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 1, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 2, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 3, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 4, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 5, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 6; ii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 9, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 10, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 11, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 12, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 13, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 14; iii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 17, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 18, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 19, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 20, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 21, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 22; iv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 25, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 26, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 27, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 28, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 29, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 30; v. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 33, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 34, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 35, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 36, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 37, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 38; vi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 41, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 42, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 43, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 44, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 45, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 46; vii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 49, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 50, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 51, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 52, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 53, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 54; viii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 57, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 58, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 59, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 60, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 61, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 62; ix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 65, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 66, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 67, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 68, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 69, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 70; x. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 73, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 74, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 75, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 76, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 77, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 78; HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 81, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 82, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 83, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 84, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 85, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 86; xii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 89, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 90, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 91, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 92, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 93, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 94; xiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 97, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 98, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 99, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 100, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 101, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 102; xiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 105, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 106, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 107, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 108, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 109, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 110; xv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 113, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 114, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 115, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 116, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 117, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 118; xvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 121, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 122, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 123, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 124, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 125, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 126; xvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 129, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 130, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 131, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 132, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 133, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 134; xviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 137, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 138, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 139, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 140, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 141, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 142; xix. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 145, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 146, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 147, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 148, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 149, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 150; xx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 153, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 154, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 155, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 156, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 157, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 158; xxi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 161, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 162, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 163, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 164, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 165, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 166; xxii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 169, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 170, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 171, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 172, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 173, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 174; xxiii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 177, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 178, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 179, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 180, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 181, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 182; xxiv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 185, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 186, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 187, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 188, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 189, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 190; xxv. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 193, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 194, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 195, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 196, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 197, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 198; xxvi. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 201, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 202, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 203, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 204, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 205, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 206; xxvii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 209, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 210, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 211, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 212, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 213, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 214; xxviii. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 217, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 218, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 219, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 220, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 221, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 222; xxix. An HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 225, an HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 226, an HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 227, an LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 228, an LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 229, and an LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 230, or xxx. HCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 233, HCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 234, HCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 235, LCDR1 comprising the amino acid sequence set forth in SEQ ID NO: 236, LCDR2 comprising the amino acid sequence set forth in SEQ ID NO: 237, and LCDR3 comprising the amino acid sequence set forth in SEQ ID NO: 238; The antibody or antigen-binding fragment thereof of any one of claims 1 to 8, comprising:

10. an amino acid sequence set forth in SEQ ID NO: 7, 15, 23, 31, 39, 47, 55, 63, 71, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, or 239, 10. The antibody or antigen-binding fragment thereof of claim 1, comprising a VH region having a homologous sequence having at least 80% sequence identity to 1, 79, 87, 95, 103, 111, 119, 127, 135, 143, 151, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231 or 239.

11. an amino acid sequence set forth in SEQ ID NO: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, or 240, 11. The antibody or antigen-binding fragment thereof of claim 1, comprising a VL region having a homologous sequence thereof having at least 80% sequence identity to 2, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232 or 240.

12. 12. The antibody or antigen-binding fragment thereof of any one of claims 1 to 11, comprising a VH / VL amino acid sequence pair selected from the group consisting of SEQ ID NOs: 7 / 8, 15 / 16, 23 / 24, 31 / 32, 39 / 40, 47 / 48, 55 / 56, 63 / 64, 71 / 72, 79 / 80, 87 / 88, 95 / 96, 103 / 104, 111 / 112, 119 / 120, 127 / 128, 135 / 136, 143 / 144, 151 / 152, 159 / 160, 167 / 168, 175 / 176, 183 / 184, 191 / 192, 199 / 200, 207 / 208, 215 / 216, 223 / 224, 231 / 232, and 239 / 240.

13. 13. The antibody or antigen-binding fragment thereof of any one of claims 1 to 12, further comprising substitution or modification of one or more amino acid residues and still maintaining binding affinity to LILRB2.

14. 14. The antibody or antigen-binding fragment thereof of claim 13, wherein at least one of the substitutions or modifications is in one or more of the CDR sequences of the VH or VL region.

15. 14. The antibody or antigen-binding fragment thereof of claim 13, wherein at least one of the substitutions or modifications is in one or more of the non-CDR sequences of the VH or VL region.

16. 16. The antibody or antigen-binding fragment of claim 1 , further comprising one or more non-natural amino acid (NNAA) substitutions.

17. The antibody or antigen-binding fragment of claim 16, wherein the NNAA is conjugable.

18. For LILRB2, i. capable of specifically binding to human LILRB2; ii. capable of binding to human LILRB2 and rhesus monkey LILRB2; iii. have a higher, lower, or equivalent binding affinity to human LILRB2 compared to reference antibody J-19.h1, B2-19, or 1E1; iv. capable of binding to human LILRB2 and human LILRB1; v. has a higher, lower or equivalent binding affinity to human LILRB1 compared to reference antibody 15G8 or Hz73D1.v1; vi. capable of functionally blocking the interaction between LILRB2 and its ligand; vii. It is capable of increasing TNF-α secretion and / or CD86 expression in immature macrophages; viii. Able to suppress M2-like polarization of macrophages to rescue T cell activation; ix. Ability to enhance anti-CD47-mediated macrophage phagocytosis; x. The ability to enhance T cell or myeloid cell inflammatory cytokine secretion (e.g., GM-CSF secretion and / or TNF-α secretion); xi. Able to inhibit the polarization of monocytes into a macrophage-like immunosuppressive phenotype; xii. Able to reverse MDSC-mediated suppression of T cell activation; and xiii. The ability to rescue T cell activity from suppression by immunosuppressive myeloid cells when used in combination with anti-PD-1 or anti-PD-L1 agents; 18. The antibody or antigen-binding fragment thereof of any one of claims 1 to 17, having one or more properties selected from the group consisting of:

19. An antibody or antigen-binding fragment thereof that competes with the antibody or antigen-binding fragment thereof of any one of claims 1 to 18 for binding to LILRB2.

20. 20. The antibody or antigen-binding fragment thereof of any one of claims 1 to 19, which is a chimeric, humanized or human antibody or an antigen-binding fragment thereof.

21. 21. The antibody or antigen-binding fragment thereof of any one of claims 1 to 20, which is a labeled antibody, a bivalent antibody, an anti-idiotypic antibody, or a fusion protein.

22. Diabody, Fab, Fab', F(ab') ２ , Fd, Fv fragment, disulfide stabilized Fv fragment (dsFv), (dsFv) ２ , a bispecific dsFv (dsFv-dsFv'), a disulfide-stabilized diabody (ds diabody), a single-chain antibody molecule (scFv), an scFv dimer (bivalent diabody), a camelized single-domain antibody, a nanobody, a domain antibody, or a bivalent domain antibody.

23. 23. The antibody or antigen-binding fragment thereof of any one of claims 1 to 22, further comprising an Fc region, optionally an Fc region of a human immunoglobulin (Ig), or optionally an Fc region of a human IgG.

24. The antibody or antigen-binding fragment thereof of claim 23, wherein the Fc region is derived from human IgG1, IgG2, IgG3, or IgG4.

25. The antibody or antigen-binding fragment thereof of claim 24, wherein the Fc region comprises the amino acid sequence set forth in SEQ ID NO:

283.

26. 26. The antibody or antigen-binding fragment thereof of any one of claims 1 to 25, further comprising a constant region, optionally a human immunoglobulin (Ig) constant region, or optionally a human IgG constant region.

27. 27. The antibody or antigen-binding fragment thereof of claim 26, wherein the constant region is derived from human IgG1, IgG2, IgG3, or IgG4.

28. 28. The antibody or antigen-binding fragment thereof of claim 27, wherein the constant region is derived from human IgG4, and optionally the constant region comprises the amino acid sequence set forth in SEQ ID NO:

281.

29. 29. The antibody or antigen-binding fragment thereof of any one of claims 1 to 28, wherein the light chain is a lambda light chain or a kappa light chain.

30. 30. The antibody or antigen-binding fragment thereof of any one of claims 1 to 29, which is a bispecific or multispecific antibody or antigen-binding fragment thereof.

31. 31. The antibody or antigen-binding fragment thereof of claim 30, which is capable of specifically binding to one or more additional antigens other than LILRB2, or a second epitope on LILRB2.

32. The one or more additional antigens other than LILRB2 include CD3, CD16a, CD33, CD38, CD45, CD123, CD146, CD228, CLL-1, FLT3, TAF1, TgPRF, HVCN1, IL-6R, IL-11R, IL17A, IL-23R, IL-33, ILDR2, LAP, TSLP, TREM-1, ANGPT2, APOE, IFNAR, CypA, DOG-1, NKp30, CSF-1R, CCR2, LRRC15, mesothelin, Dickkopf2, DLL3, HER-2, and C10orf. 54, TrkA, MEKK1, KRAS, ERK, XPO1, mTORC1 / 2, PAK4, NAMPT, ATR, EGFR, FGF R, VEGF, c-MET, Her2, Her3, CTLA4, GITA, CD112R, CD2, CD7, CD16, CD19, C D20, CD24, CD27, CD30, CD34, CD37, CD39, CD70, CD73, CD83, CD28, CD80 (B 7-1), CD86 (B7-2), CD40, CD40L (CD154), CD47, SIRPα, CD122, CD137, CD1 37L, OX40 (CD134), OX40L (CD252), BCMA (e.g. BCMA02), PSMA, CLDN18 (e.g. CLDN18.2), NKG2C, 4-1BB, LIGHT, PVRIG, SLAMF7, HVEM, BAFFR, ICAM- 1, 2B4, LFA-1, GITR, ICOS (CD278), ICOSLG (CD275), LAG3 (CD223), A2AR, B7-H3 (CD276), B7-H4 (VTCN1), B7-H5, BTLA (CD272), CD160, CTLA-4 (CD1 52), GPRC5D, IDO1, IDO2, TDO, KIR, LAIR-1, NOX2, PD-1, PD-L1, PD-L2, TIM-3, VISTA, SIGLEC-7 (CD328), SIGLEC-9 (CD329), SIGLEC-15, TIGIT, PVR (CD155), LILRB1, LILRB3, LILRB4, LILRB5, FLT3L, TLR3, CLEC9A, DEC-205, STING, IL-12, IDO, and TGFβ.

33. 33. The antibody or antigen-binding fragment thereof of any one of claims 1 to 32, linked to one or more conjugate moieties.

34. 34. The antibody or antigen-binding fragment thereof of claim 33, wherein the conjugate moiety comprises a clearance modifier, a chemotherapeutic agent, a toxin, a radioisotope, a lanthanide, a detectable label, a DNA alkylating agent, a topoisomerase inhibitor, a tubulin binding agent, a purification moiety, or another anti-cancer drug.

35. 35. The antibody or antigen-binding fragment thereof of claim 33 or 34, wherein the conjugate moiety is covalently attached directly or via a linker.

36. A chimeric antigen receptor comprising the antibody or antigen-binding fragment thereof according to any one of claims 1 to 32, a transmembrane domain, and an intracellular signal domain.

37. 37. The chimeric antigen receptor of claim 36, wherein the transmembrane region comprises the transmembrane region of CD3, CD4, CD8, or CD28.

38. The chimeric antigen receptor of claim 36, wherein the intracellular signal region is selected from the group consisting of an intracellular signal region sequence of CD3, FcγRI, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, a TLR, or a combination thereof.

39. 39. The chimeric antigen receptor of any one of claims 36 to 38, wherein the antigen-binding fragment is an scFv.

40. 40. The chimeric antigen receptor of any one of claims 36 to 39, wherein the chimeric antigen receptor is transplanted into allogeneic, autologous or xenogeneic cells.

41. 41. The chimeric antigen receptor of any one of claims 36 to 40, wherein the chimeric antigen receptor is engrafted into an immune effector cell.

42. 42. The chimeric antigen receptor of any one of claims 36 to 41, wherein the chimeric antigen receptor is transplanted into a T cell, a natural killer cell, a macrophage cell, or a tumor-infiltrating lymphocyte.

43. 36. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and one or more pharmaceutically acceptable carriers.

44. 43. An isolated polynucleotide encoding an antibody or antigen-binding fragment thereof according to any one of claims 1 to 32, and / or a chimeric antigen receptor according to any one of claims 36 to 42.

45. 45. A vector comprising the isolated polynucleotide of claim 44.

46. 46. ​​A host expression system comprising the vector of claim 45 or having the polynucleotide of claim 44 integrated into its genome.

47. 47. The host expression system of claim 46, which is a microorganism, yeast, or mammalian cell, optionally wherein the microorganism is selected from the group consisting of Escherichia coli and Bacillus subtilis, optionally wherein the yeast is Saccharomyces, and optionally wherein the mammalian cell is selected from the group consisting of COS, CHO-S, CHO-K1, HEK-293, and 3T3 cells.

48. 46. ​​A virus comprising the vector of claim 45.

49. A kit comprising the antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and / or the chimeric antigen receptor of any one of claims 36 to 42 and / or the pharmaceutical composition of claim 43, and a second therapeutic agent.

50. 47. A method of expressing the antibody or antigen-binding fragment thereof of any one of claims 1 to 32 or the chimeric antigen receptor of any one of claims 36 to 42, comprising culturing the host expression system of claim 46 under conditions in which the antibody or antigen-binding fragment thereof of any one of claims 1 to 32 or the chimeric antigen receptor of any one of claims 36 to 42 is expressed.

51. 44. A method for treating, preventing or alleviating a disease, disorder or condition in a subject, comprising administering to the subject a therapeutically effective amount of the antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and / or the chimeric antigen receptor of any one of claims 36 to 42 and / or the pharmaceutical composition of claim 43.

52. 52. The method of claim 51, wherein the disease, disorder or condition is an immune disease, an inflammatory disease, cancer or a neurological disease.

53. 53. The method of claim 52, wherein the cancer is a solid tumor or a hematological tumor.

54. The disease, disorder, or condition may be Kawasaki disease, toxoplasmosis, multiple sclerosis, systemic lupus erythematosus, lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), lung adenocarcinoma, lung squamous cell carcinoma, or Lewis lung carcinoma), peritoneal cancer, carcinoid cancer, bone cancer, pancreatic cancer, primitive neuroectodermal tumor, skin cancer, gallbladder cancer, head and neck cancer, squamous cell carcinoma, uterine cancer, ovarian cancer, rectal cancer, prostate cancer, bladder cancer (e.g., urothelial carcinoma), cancer of the anal region (e.g., anal squamous cell carcinoma), stomach cancer (e.g., gastrointestinal cancer), esophageal cancer, colon cancer, breast cancer, uterine cancer, liver cancer (e.g., hepatoblastoma, hepatocellular carcinoma / hepatic carcinoma), carcinoma, or liver cancer), bile duct cancer, sarcoma, colon cancer, fallopian tube cancer, salivary gland cancer, cervical cancer, endometrial or uterine cancer, osteosarcoma, vaginal cancer, vulvar cancer, esophageal cancer, small intestine cancer, endocrine system cancer, thyroid cancer, parathyroid cancer, adrenal cancer, nasopharyngeal cancer, soft tissue sarcoma, polycythemia vera, urethral cancer, penile cancer, kidney or ureter cancer (e.g., rhabdoid tumor of the kidney), cutaneous T-cell lymphoma, medulloblastoma, nephroblastoma, myelodysplastic syndrome, chronic and non-chronic myeloproliferative disorders, choroid plexus papilloma, renal cell carcinoma, renal pelvis cancer, central nervous system (CNS) tumors, soft tissue sarcomas (e.g., rhabdomyosarcoma, fibrosarcoma, Kaposi's sarcoma), spinal axis tumors, gliomas (e.g., ependymoma, astrocytoma, anaplastic astrocytoma, oligodendroglioma, eye cancer (e.g., retinoblastoma), brain stem glioma, or mixed glioma such as oligoastrocytoma), brain tumor (e.g., glioblastoma / glioblastoma multiforme (GBM), non-glioblastoma brain tumor, or meningioma), melanoma (e.g., cutaneous melanoma or intraocular melanoma), thrombocythemia, mesothelioma, mycosis fungoides, Sezary syndrome, idiopathic myelofibrosis, solitary plasmacytoma, vestibular schwannoma, Ewing's sarcoma, chondrosarcoma, MYH-associated polyposis, pituitary adenoma, pediatric sarcoma (e.g., neuroblastoma, rhabdomyosarcoma, and osteosarcoma), etc. childhood cancers, blood cancers, Hodgkin's lymphoma, non-Hodgkin's lymphoma, leukemia (e.g., lymphocytic / lymphoblastic leukemia), chronic or acute leukemia, mast cell leukemia, lymphocytic lymphoma, primary CNS lymphoma, chronic lymphocytic leukemia (CLL), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), acute myeloid leukemia (AML), chronic myelomonocytic leukemia (CMML), chronic lymphoblastic leukemia, acute lymphoblastic leukemia, hairy cell leukemia (HCL), Burkitt's lymphoma (BL), multiple myeloma (e.g., relapsed or refractory multiple myeloma),54. The method of any one of claims 51 to 53, wherein the lymphoma is selected from the group consisting of T-cell or B-cell lymphoma, mantle cell lymphoma (MCL) (e.g., relapsed or refractory mantle cell lymphoma), malignant melanoma, diffuse large B-cell lymphoma (DLBCL), DLBCL arising from follicular lymphoma, high-grade B-cell lymphoma, primary mediastinal large B-cell lymphoma, follicular lymphoma (FL), and primary mediastinal B-cell lymphoma.

55. 55. The method of any one of claims 51 to 54, wherein the subject is a human.

56. 56. The method of any one of claims 51 to 55, wherein the administration is via a parenteral route, including subcutaneous, intraperitoneal, intravenous, intramuscular, or intradermal injection, or a non-parenteral route, including transdermal, oral, intranasal, intraocular, sublingual, rectal, or topical.

57. 57. The method of any one of claims 51 to 56, further comprising administering an additional therapeutic agent to the subject in need thereof.

58. 58. The method of claim 57, wherein the additional therapeutic agent is selected from the group consisting of an active agent, an imaging agent, a cytotoxic agent, an angiogenesis inhibitor, a kinase inhibitor, a costimulatory molecule agonist, a co-inhibitory molecule blocker, an adhesion molecule blocker, an anti-cytokine antibody or functional fragment thereof, a detectable label or reporter, an antibacterial agent, a gene editing agent, a beta agonist, a viral RNA inhibitor, a polymerase inhibitor, an interferon, and a microRNA.

59. 58. The method of claim 57, wherein the additional therapeutic agent is administered to the subject in need thereof before, after, or simultaneously with the antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and / or the chimeric antigen receptor of any one of claims 36 to 42 and / or the pharmaceutical composition of claim 43.

60. A method for regulating LILRB2 activity in a LILRB2-expressing cell, comprising exposing the LILRB2-expressing cell to an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43.

61. 61. The method of claim 60, wherein the LILRB2-expressing cell is a hematopoietic stem cell, a dendritic cell, a monocyte, a macrophage, a neutrophil, a basophil, a platelet, a progenitor mast cell, an endothelial cell, a neuron, or an osteoclast.

62. A method for blocking the interaction of LILRB2 with its ligand, comprising exposing LILRB2 to an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43.

63. 63. The method of claim 62, wherein the ligand is HLA-G.

64. 63. The method of claim 62, wherein the LILRB2 is expressed in or on a cell.

65. 65. The method of claim 64, wherein the cell is selected from a hematopoietic stem cell, a dendritic cell, a monocyte, a macrophage, a neutrophil, a basophil, a platelet, a T cell, a B cell, a Treg, a precursor mast cell, an endothelial cell, a neuron, or an osteoclast.

66. A method for inducing TNF-α production and / or CD86 expression, comprising exposing immature macrophages to the antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and / or the chimeric antigen receptor of any one of claims 36 to 42 and / or the pharmaceutical composition of claim 43.

67. A method for inhibiting M2-like polarization of immature macrophages, comprising exposing the immature macrophages to an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43.

68. 68. The method of claim 67, wherein the purpose of said suppression is to rescue T cell activation.

69. 44. A method for inducing or enhancing phagocytosis of target cells in vivo or in vitro, comprising exposing the target cells to an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43.

70. 44. A method for enhancing anti-CD47 agent-mediated phagocytosis of a target cell, comprising exposing the target cell to an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43.

71. Use of an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35, a chimeric antigen receptor described in any one of claims 36 to 42, and / or a pharmaceutical composition described in claim 43 in combination with an anti-CD47 agent to induce or enhance phagocytosis of target cells.

72. 42。 A kit useful for inducing or enhancing phagocytosis of target cells, comprising: (a) an antibody or antigen-binding fragment thereof according to any one of claims 1 to 35 and / or a chimeric antigen receptor according to any one of claims 36 to 42 and / or a pharmaceutical composition according to claim 43; and (b) an anti-CD47 agent.

73. 73. The method of claim 69 or 70, or the use of claim 71, or the kit of claim 72, wherein the target cell is an antigen-presenting cell, a macrophage, a cancer cell or a cell infected by a pathogen.

74. 73. The method of claim 70, or the use of claim 71, or the kit of claim 72, wherein the anti-CD47 agent is an anti-CD47 antibody or an antigen-binding fragment thereof.

75. 42. A method for detecting the presence or amount of LILRB2 in a sample, comprising contacting the sample with an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43, and determining the presence or amount of LILRB2 in the sample.

76. A method for diagnosing a LILRB2-related disease, disorder, or condition in a subject, comprising: a) contacting a sample taken from the subject with an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or the pharmaceutical composition described in claim 43; b) determining the presence or amount of LILRB2 in the sample; and c) correlating the presence or amount of LILRB2 with the presence or state of the LILRB2-related disease, disorder, or condition in the subject.

77. Use of an antibody or antigen-binding fragment thereof of any one of claims 1 to 35 and / or a chimeric antigen receptor of any one of claims 36 to 42 and / or a pharmaceutical composition of claim 43 in the manufacture of a medicament for treating a LILRB2-related disease, disorder or condition in a subject.

78. Use of an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43 in the manufacture of a diagnostic reagent for diagnosing a LILRB2-related disease, disorder or condition.

79. A kit comprising an antibody or antigen-binding fragment thereof described in any one of claims 1 to 35 and / or a chimeric antigen receptor described in any one of claims 36 to 42 and / or a pharmaceutical composition described in claim 43, and which is useful for detecting LILRB2, optionally recombinant LILRB2, LILRB2 expressed on the cell surface, or LILRB2-expressing cells.

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