CCR8 antibodies and their uses

Abstract

The present invention relates to an isolated antigen-binding protein capable of binding CCR8 derived from a primate, a pharmaceutical composition comprising the antigen-binding protein, and the use of said antigen-binding protein and / or pharmaceutical composition in the prevention and / or treatment of tumors or cancer.

Description

[Technical field]

[0001] The present invention relates to the biomedical or biopharmaceutical technical field, more specifically to an anti-CCR8 monoclonal antibody molecule and its uses. [Background technology]

[0002] Tumor infiltrating CD4 + FoxP3 + Regulatory cells (Tregs) are one of the major immunosuppressive cell populations in the tumor microenvironment (TME). It has been well documented that systematic depletion of tumor-infiltrating CD4+FoxP3+Tregs enhances antitumor activity in multiple mouse tumor models.

[0003] Chemokine receptor CCR8, also known as CY6, CKR-L1 or TER1, is a G protein-conjugated seventh transmembrane protein. In humans and mice, it is found to be mainly expressed on Treg and a small portion of Th2, but not on Th1. In breast cancer, human CCR8 is highly expressed on Treg residing at the tumor site compared with normal tissues and peripheral blood, and it has been demonstrated that the CCR8+Treg cells in this portion are a cell group that mainly plays an immunosuppressive role. Analysis has shown that high expression of CCR8 is positively correlated with the survival rate of various tumors, including breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer, colon cancer, etc.

[0004] CCL1 is one of the major ligands for endogenous expression of CCR8. CCL1 is overexpressed in many types of tumor tissues and recruits CCR8-expressing Treg cells to infiltrate into tumor tissues. Blocking CCL1-CCR8 action can block the immunosuppressive effect of Treg and increase the antitumor effect.

[0005] Targeting CCR8 to eliminate CCR8+ Tregs in the tumor environment or block CCL1-mediated migration of CCR8+ Tregs into tumor tissues may provide a potential new route for tumor immunotherapy. Summary of the Invention

[0006] The present application provides an isolated antigen-binding protein capable of binding to primate (human and / or monkey)-derived CCR8, blocking the binding between CCR8 and its ligand CCL1, blocking intracellular calcium influx signals induced by CCL1, inhibiting cell migration induced by CCL1, having ADCC reporter gene biological activity, and having NK cell-mediated ADCC biological activity. The isolated antigen-binding protein of the present application can also specifically target Treg cells with immunosuppressive activity infiltrating into tumor tissues, and shows clear antitumor activity in animal experiments.

[0007] In one aspect, the present application provides an isolated antigen binding protein, wherein said antigen binding protein comprises an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:359, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:38, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:360.

[0008] In some embodiments, the HCDR1 comprises an amino acid sequence set forth in any one of SEQ ID NOs:15, 16, 21, and 22, the HCDR2 comprises an amino acid sequence set forth in SEQ ID NO:38, and the HCDR3 comprises an amino acid sequence set forth in any one of SEQ ID NOs:65, 68, 72, and 73.

[0009] In some embodiments, the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from any of the following groups: (1) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (2) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (3) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68, (4) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, (5) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73, (6) HCDR1: SEQ ID NO: 21, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (7) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (8) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, and (9) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73.

[0010] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and the VH comprises an amino acid sequence set forth in any one of SEQ ID NOs: 169, 172, 177, and 181-197.

[0011] In some embodiments, the antigen binding protein further comprises an antibody heavy chain constant region.

[0012] In some embodiments, the heavy chain constant region is derived from a human IgG constant region.

[0013] In some embodiments, the heavy chain constant region is derived from a human IgG1 constant region.

[0014] In some embodiments, the heavy chain constant region comprises an amino acid sequence set forth in any one of SEQ ID NOs:356-357.

[0015] In some embodiments, the antigen binding protein comprises an antibody heavy chain, and the antibody heavy chain comprises an amino acid sequence set forth in any one of SEQ ID NOs:251, 254, 259-262, 266-284.

[0016] In some embodiments, the antigen binding protein comprises an antibody light chain or fragment thereof, wherein the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO:361, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO:362.

[0017] In some embodiments, the LCDR1 comprises an amino acid sequence set forth in any one of SEQ ID NOs:105, 106, 107, 111, and 112, the LCDR2 comprises an amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 comprises an amino acid sequence set forth in any one of SEQ ID NOs:142, 150, 151, and 152.

[0018] In some embodiments, the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (2) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (3) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 150; (4) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 151; (5) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 152; (6) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (7) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; and (8) LCDR1: SEQ ID NO: 112, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142.

[0019] In some embodiments, the antigen binding protein comprises an antibody light chain variable region, VL, and said VL comprises an amino acid sequence set forth in any one of SEQ ID NOs: 214, 217, 220, 223, 227-230, 232-234, 236, 237, 242, 243, and 244.

[0020] In some embodiments, the antigen binding protein further comprises an antibody light chain constant region.

[0021] In some embodiments, the light chain constant region comprises the amino acid sequence set forth in SEQ ID NO:358.

[0022] In some embodiments, the antigen binding protein comprises an antibody light chain, and the antibody light chain comprises an amino acid sequence set forth in any one of SEQ ID NOs:321, 324, 327, 330, 334-337, 339-341, 343, 344, 349, 350, and 351.

[0023] In some embodiments, the antigen binding protein comprises an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (3) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (4) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (5) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68; (6) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (7) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; (8) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 21, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (9) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (10) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (11) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; (12) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 150, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (13) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 151, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (14) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 152, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (15) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (16) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68; (17) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (18) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (19) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; and (20) LCDR1: SEQ ID NO: 112, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65.

[0024] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and an antibody light chain variable region, VL, and the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 214 and VH: SEQ ID NO: 169; (2) VL: SEQ ID NO: 217 and VH: SEQ ID NO: 172; (3) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 172; (4) VL: SEQ ID NO: 223 and VH: SEQ ID NO: 177; (5) VL: SEQ ID NO: 227 and VH: SEQ ID NO: 172; (6) VL: SEQ ID NO: 228 and VH: SEQ ID NO: 172; (7) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 181; (8) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 182; (9) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 183; (10) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 184; (11) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 185; (12) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 186; (13) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 187; (14) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 188; (15) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 189; (16) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 190; (17) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 191; (18) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 192; (19) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 193; (20) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 172; (21) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 172; (22) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 172; (23) VL: SEQ ID NO: 233 and VH: SEQ ID NO: 172; (24) VL: SEQ ID NO: 234 and VH: SEQ ID NO: 172; (25) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 185; (26) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 191; (27) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 185; (28) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 188; (29) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 191; (30) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 188; (31) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 191; (32) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 194; (33) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 195; (34) VL: SEQ ID NO: 236 and VH: SEQ ID NO: 194; (35) VL: SEQ ID NO: 236 and VH: SEQ ID NO: 195; (36) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 196; (37) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 197; (38) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 196; (39) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 197; (40) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 188; (41) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 185; (42) VL: SEQ ID NO: 242 and VH: SEQ ID NO: 172; (43) VL: SEQ ID NO: 243, and VH: SEQ ID NO: 172; and (44) VL: SEQ ID NO: 244, and VH: SEQ ID NO: 172.

[0025] In one aspect, the present application provides an isolated antigen binding protein, wherein said antigen binding protein comprises an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:363, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:364, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:365.

[0026] In some embodiments, the HCDR1 comprises an amino acid sequence set forth in any one of SEQ ID NOs:15-18, the HCDR2 comprises an amino acid sequence set forth in any one of SEQ ID NOs:37-39, and the HCDR3 comprises an amino acid sequence set forth in any one of SEQ ID NOs:65-67.

[0027] In some embodiments, the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from any of the following groups: (1) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 37, and HCDR3: SEQ ID NO: 65, (2) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (3) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (4) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66, (5) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 67, (6) HCDR1: SEQ ID NO: 17, HCDR2: SEQ ID NO: 39, and HCDR3: SEQ ID NO: 65, and (7) HCDR1: SEQ ID NO: 18, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65.

[0028] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and the VH comprises an amino acid sequence set forth in any one of SEQ ID NOs: 167, 168, and 170-176.

[0029] In some embodiments, the antigen binding protein further comprises an antibody heavy chain constant region.

[0030] In some embodiments, the heavy chain constant region is derived from a human IgG constant region.

[0031] In some embodiments, the heavy chain constant region is derived from a human IgG1 constant region.

[0032] In some embodiments, the heavy chain constant region comprises an amino acid sequence set forth in any one of SEQ ID NOs:356-357.

[0033] In some embodiments, the antigen binding protein comprises an antibody heavy chain, and the antibody heavy chain comprises an amino acid sequence set forth in any one of SEQ ID NOs:249, 250, 252, 253, 255, 256, 257, 258, and 261.

[0034] In some embodiments, the antigen binding protein comprises an antibody light chain or fragment thereof, wherein the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO:366, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO:141.

[0035] In some embodiments, the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141; and (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141.

[0036] In some embodiments, the antigen binding protein comprises an antibody light chain variable region, VL, and said VL comprises an amino acid sequence set forth in any one of SEQ ID NOs: 212, 213, 215, 216, 218, 219, 221, 222, 231 and 235.

[0037] In some embodiments, the antigen binding protein further comprises an antibody light chain constant region.

[0038] In some embodiments, the light chain constant region comprises the amino acid sequence set forth in SEQ ID NO:358.

[0039] In some embodiments, the antigen binding protein comprises an antibody light chain, and the antibody light chain comprises an amino acid sequence set forth in any one of SEQ ID NOs:319, 320, 322, 323, 325, 326, 328, 329, 338, and 342.

[0040] In some embodiments, the antigen binding protein comprises an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 37, and HCDR3: SEQ ID NO: 65; (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (3) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 17, HCDR2: SEQ ID NO: 39, and HCDR3: SEQ ID NO: 65; (4) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (5) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 18, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (6) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; and (7) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 67.

[0041] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and an antibody light chain variable region, VL, and the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 212 and VH: SEQ ID NO: 167; (2) VL: SEQ ID NO: 213 and VH: SEQ ID NO: 168; (3) VL: SEQ ID NO: 215 and VH: SEQ ID NO: 170; (4) VL: SEQ ID NO: 216 and VH: SEQ ID NO: 171; (5) VL: SEQ ID NO: 218 and VH: SEQ ID NO: 173; (6) VL: SEQ ID NO: 219 and VH: SEQ ID NO: 174; (7) VL: SEQ ID NO: 221 and VH: SEQ ID NO: 175; (8) VL: SEQ ID NO: 222 and VH: SEQ ID NO: 176; (9) VL: SEQ ID NO: 231, and VH: SEQ ID NO: 172; and (10) VL: SEQ ID NO: 235, and VH: SEQ ID NO: 172.

[0042] In one aspect, the present application provides an isolated antigen binding protein, said antigen binding protein comprising an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 16, 19, 20, 23, 24 and 25, said HCDR2 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 38 and 40-47, and said HCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 66, 69, 70, 71 and 74-79.

[0043] In some embodiments, the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from any of the following groups: (1) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 69; (2) HCDR1: SEQ ID NO: 20, HCDR2: SEQ ID NO: 41, and HCDR3: SEQ ID NO: 70; (3) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 71; (4) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 74; (5) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 44, and HCDR3: SEQ ID NO: 76; (6) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 45, and HCDR3: SEQ ID NO: 77; (7) HCDR1: SEQ ID NO: 23, HCDR2: SEQ ID NO: 43, and HCDR3: SEQ ID NO: 75; (8) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 46, and HCDR3: SEQ ID NO: 78; (9) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (10) HCDR1: SEQ ID NO: 25, HCDR2: SEQ ID NO: 47, and HCDR3: SEQ ID NO: 79; and (11) HCDR1: SEQ ID NO: 24, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 79.

[0044] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and the VH comprises an amino acid sequence set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205.

[0045] In some embodiments, the antigen binding protein further comprises an antibody heavy chain constant region.

[0046] In some embodiments, the heavy chain constant region is derived from a human IgG constant region.

[0047] In some embodiments, the heavy chain constant region is derived from a human IgG1 constant region.

[0048] In some embodiments, the heavy chain constant region comprises an amino acid sequence set forth in any one of SEQ ID NOs:356-357.

[0049] In some embodiments, the antigen binding protein comprises an antibody heavy chain, and the antibody heavy chain comprises an amino acid sequence set forth in any one of SEQ ID NOs: 263, 264, 265, and 285-298.

[0050] In some embodiments, the antigen binding protein comprises an antibody light chain or fragment thereof, wherein the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises an amino acid sequence set forth in any one of SEQ ID NOs: 104, 105, 108-110 and 113-117, the LCDR2 comprises an amino acid sequence set forth in any one of SEQ ID NOs: 127-134, and the LCDR3 comprises an amino acid sequence set forth in any one of SEQ ID NOs: 141, 143-149 and 153.

[0051] In some embodiments, the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 108, LCDR2: SEQ ID NO: 128, and LCDR3: SEQ ID NO: 143, (2) LCDR1: SEQ ID NO: 109, LCDR2: SEQ ID NO: 129, and LCDR3: SEQ ID NO: 144, (3) LCDR1: SEQ ID NO: 110, LCDR2: SEQ ID NO: 130, and LCDR3: SEQ ID NO: 145, (4) LCDR1: SEQ ID NO: 113, LCDR2: SEQ ID NO: 131, and LCDR3: SEQ ID NO: 146, (5) LCDR1: SEQ ID NO: 115, LCDR2: SEQ ID NO: 133, and LCDR3: SEQ ID NO: 148, (6) LCDR1: SEQ ID NO: 116, LCDR2: SEQ ID NO: 134, and LCDR3: SEQ ID NO: 149, (7) LCDR1: SEQ ID NO: 114, LCDR2: SEQ ID NO: 132, and LCDR3: SEQ ID NO: 147, (8) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141, (9) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141, and (10) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, and LCDR3: SEQ ID NO: 153.

[0052] In some embodiments, the antigen binding protein comprises an antibody light chain variable region, VL, and said VL comprises an amino acid sequence set forth in any one of SEQ ID NOs: 224-226, 238-241 and 245-248.

[0053] In some embodiments, the antigen binding protein further comprises an antibody light chain constant region.

[0054] In some embodiments, the light chain constant region comprises the amino acid sequence set forth in SEQ ID NO:358.

[0055] In some embodiments, the antigen binding protein comprises an antibody light chain, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NOs: 331-333, 345-348 and 352-355.

[0056] In some embodiments, the antigen binding protein comprises an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 108, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 143, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 69; (2) LCDR1: SEQ ID NO: 109, LCDR2: SEQ ID NO: 129, LCDR3: SEQ ID NO: 144, HCDR1: SEQ ID NO: 20, HCDR2: SEQ ID NO: 41, and HCDR3: SEQ ID NO: 70; (3) LCDR1: SEQ ID NO: 110, LCDR2: SEQ ID NO: 130, LCDR3: SEQ ID NO: 145, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 71; (4) LCDR1: SEQ ID NO: 113, LCDR2: SEQ ID NO: 131, LCDR3: SEQ ID NO: 146, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 74; (5) LCDR1: SEQ ID NO: 115, LCDR2: SEQ ID NO: 133, LCDR3: SEQ ID NO: 148, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 44, and HCDR3: SEQ ID NO: 76; (6) LCDR1: SEQ ID NO: 116, LCDR2: SEQ ID NO: 134, LCDR3: SEQ ID NO: 149, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 45, and HCDR3: SEQ ID NO: 77; (7) LCDR1: SEQ ID NO: 114, LCDR2: SEQ ID NO: 132, LCDR3: SEQ ID NO: 147, HCDR1: SEQ ID NO: 23, HCDR2: SEQ ID NO: 43, and HCDR3: SEQ ID NO: 75; (8) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 46, and HCDR3: SEQ ID NO: 78; (9) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (10) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 153, HCDR1: SEQ ID NO: 25, HCDR2: SEQ ID NO: 47, and HCDR3: SEQ ID NO: 79; and (11) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 153, HCDR1: SEQ ID NO: 24, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 79.

[0057] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and an antibody light chain variable region, VL, and the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 224 and VH: SEQ ID NO: 178; (2) VL: SEQ ID NO: 225 and VH: SEQ ID NO: 179; (3) VL: SEQ ID NO: 226 and VH: SEQ ID NO: 180; (4) VL: SEQ ID NO: 238 and VH: SEQ ID NO: 198; (5) VL: SEQ ID NO: 240 and VH: SEQ ID NO: 200; (6) VL: SEQ ID NO: 241 and VH: SEQ ID NO: 201; (7) VL: SEQ ID NO: 239 and VH: SEQ ID NO: 199; (8) VL: SEQ ID NO: 245 and VH: SEQ ID NO: 202; (9) VL: SEQ ID NO: 246 and VH: SEQ ID NO: 203; (10) VL: SEQ ID NO: 248, and VH: SEQ ID NO: 205; and (11) VL: SEQ ID NO: 247, and VH: SEQ ID NO: 204.

[0058] In one aspect, the present application provides an isolated antigen binding protein, wherein said antigen binding protein comprises an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:22, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:367, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:368.

[0059] In some embodiments, the HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:22, the HCDR2 comprises the amino acid sequence set forth in any one of SEQ ID NOs:38 and 48, and the HCDR3 comprises the amino acid sequence set forth in any one of SEQ ID NOs:72, 80, 81, 82, and 83.

[0060] In some embodiments, the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from any of the following groups: (1) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, (2) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 80, (3) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 81, (4) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 80, (5) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 81, (6) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 82, and (7) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 83.

[0061] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and said VH comprises an amino acid sequence set forth in any one of SEQ ID NOs: 196 and 206-211.

[0062] In some embodiments, the antigen binding protein further comprises an antibody heavy chain constant region.

[0063] In some embodiments, the heavy chain constant region is derived from a human IgG constant region.

[0064] In some embodiments, the heavy chain constant region is derived from a human IgG1 constant region.

[0065] In some embodiments, the heavy chain constant region comprises an amino acid sequence set forth in any one of SEQ ID NOs:356-357.

[0066] In some embodiments, the antigen binding protein comprises an antibody heavy chain, and the antibody heavy chain comprises an amino acid sequence set forth in any one of SEQ ID NOs:299-318.

[0067] In some embodiments, the antigen binding protein comprises an antibody light chain or fragment thereof, wherein the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises the amino acid sequence set forth in SEQ ID NO:111, the LCDR2 comprises the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 comprises the amino acid sequence set forth in SEQ ID NO:142.

[0068] In some embodiments, the antigen binding protein comprises an antibody light chain variable region, VL, and said VL comprises the amino acid sequence shown in SEQ ID NO:237.

[0069] In some embodiments, the antigen binding protein further comprises an antibody light chain constant region.

[0070] In some embodiments, the light chain constant region comprises the amino acid sequence set forth in SEQ ID NO:358.

[0071] In some embodiments, the antigen binding protein comprises an antibody light chain, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO:344.

[0072] In some embodiments, the antigen binding protein comprises an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (2) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 80; (3) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 81; (4) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 80; (5) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 81; (6) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 82; and (7) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 83.

[0073] In some embodiments, the antigen binding protein comprises an antibody heavy chain variable region, VH, and an antibody light chain variable region, VL, and the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 196; (2) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 206; (3) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 207; (4) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 208; (5) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 209; (6) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 210; and (7) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 211.

[0074] In some embodiments, the antigen binding protein has one or more of the following properties: a) 2 × 10 -8 can bind to primate-derived CCR8 with an EC50 value of M or lower; b) capable of blocking the binding of CCR8 to the ligand CCL1; c) inhibiting calcium ion fluxes induced by CCL1; and d) It can inhibit CCL1-induced cell migration.

[0075] In some embodiments, the primate comprises a human and / or a monkey.

[0076] In some embodiments, the antigen binding protein comprises an antibody or an antigen-binding fragment thereof.

[0077] In some embodiments, the antigen binding protein comprises a full length antibody, a Fab, a Fab', a F(ab')2, an Fv, preferably an scFv, a di-scFv, a bispecific antibody, a multispecific antibody, a heavy chain antibody and / or a single domain antibody, or a monoclonal and / or polyclonal antibody produced by said antibodies.

[0078] In some embodiments, the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a humanized antibody, and a fully human antibody.

[0079] In one aspect, the present application provides an isolated nucleic acid molecule or molecules, said nucleic acid molecule encoding said isolated antigen binding protein.

[0080] In one aspect, the present application provides one or more vectors, said vectors comprising the nucleic acid molecule described above.

[0081] In one aspect, the present application provides one or more cells, said cells comprising said nucleic acid molecule or said vector.

[0082] In one aspect, the present application provides a method of producing one of said isolated antigen binding proteins, said method comprising culturing said cell under conditions allowing expression of said isolated antigen binding protein.

[0083] In one aspect, the present application provides a chimeric antigen receptor, said chimeric antigen receptor comprising said antigen binding protein.

[0084] In one aspect, the present application provides a genetically modified cell, the genetically modified cell comprising the chimeric antigen receptor described above. In some embodiments, the genetically modified cell comprises a eukaryotic cell. In some embodiments, the genetically modified cell comprises an isolated human cell. In some embodiments, the genetically modified cell comprises an immune cell, such as a T cell or a NK cell.

[0085] In one aspect, the present application provides an antibody drug conjugate, the antibody drug conjugate comprising a cytotoxic agent and the antigen binding protein described above.

[0086] In one aspect, the present application provides a pharmaceutical composition, comprising the isolated antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, and / or the antibody drug conjugate, and optionally a pharma- ceutical acceptable vector.

[0087] In one aspect, the present application provides a kit or administration device, the kit or administration device comprising the antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate and / or the pharmaceutical composition; preferably, the kit further comprises (i) a device for administering the antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate and / or the pharmaceutical composition; and / or (ii) instructions for use.

[0088] In one aspect, the present application provides the use of one of said antigen binding proteins, said nucleic acid molecule, said vector, said cell, said chimeric antigen receptor, said genetically modified cell, said antibody drug conjugate and / or said pharmaceutical composition in the manufacture of a drug, wherein said drug is used for preventing, alleviating and / or treating a CCR8 mediated disease or disorder.

[0089] In some embodiments, the CCR8-mediated disease or disorder comprises a tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a solid tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a non-solid tumor.

[0090] In certain embodiments, the CCR8-mediated disease or disorder comprises breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and / or colon cancer.

[0091] In one aspect, the present application provides a method of inhibiting a CCL1-mediated calcium ion flux, the method comprising administering said isolated antigen binding protein and / or said pharmaceutical composition.

[0092] In certain embodiments, the method is an in vitro method or a method for non-diagnostic purposes.

[0093] In one aspect, the present application provides a method of inhibiting a CCL1-induced cell migration, the method comprising administering said isolated antigen binding protein and / or said pharmaceutical composition.

[0094] In certain embodiments, the method is an in vitro method or a method for non-diagnostic purposes.

[0095] In one aspect, the present application provides a method for preventing, alleviating or treating a CCR8-mediated disease or disorder, the method comprising administering the antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate and / or the pharmaceutical composition to a subject in need thereof.

[0096] In some embodiments, the CCR8-mediated disease or disorder comprises a tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a solid tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a non-solid tumor.

[0097] In certain embodiments, the CCR8-mediated disease or disorder comprises breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and / or colon cancer.

[0098] In one aspect, the present application provides said antigen binding protein, said nucleic acid molecule, said vector, said cell, said chimeric antigen receptor, said genetically modified cell, said antibody drug conjugate and / or said pharmaceutical composition, wherein said drug is used for preventing, alleviating and / or treating a CCR8 mediated disease or disorder.

[0099] In some embodiments, the CCR8-mediated disease or disorder comprises a tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a solid tumor. In some embodiments, the CCR8-mediated disease or disorder comprises a non-solid tumor.

[0100] In certain embodiments, the CCR8-mediated disease or disorder comprises breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and / or colon cancer. Further aspects of the invention are described below: [Section 1] An isolated antigen binding protein comprising an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:359, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:38, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:360. [Section 2] 2. The isolated antigen binding protein of claim 1, wherein said HCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 15, 16, 21 and 22, said HCDR2 comprises an amino acid sequence as set forth in SEQ ID NO: 38, and said HCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 65, 68, 72 and 73; preferably, said HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from the group consisting of: (1) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (2) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (3) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68, (4) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, (5) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73, (6) HCDR1: SEQ ID NO: 21, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (7) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (8) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, and (9) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73. [Section 3] 3. The isolated antigen-binding protein of any one of claims 1 to 2, comprising an antibody heavy chain variable region VH, and wherein the VH comprises an amino acid sequence set forth in any one of SEQ ID NOs: 169, 172, 177 and 181-197. [Section 4] 4. The isolated antigen binding protein of any one of claims 1 to 3, comprising an antibody light chain or a fragment thereof, the antibody light chain or a fragment thereof comprising LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises the amino acid sequence shown in SEQ ID NO:361, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO:127, and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO:362. [Section 5] 5. The isolated antigen binding protein of clause 4, wherein said LCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 105, 106, 107, 111 and 112, said LCDR2 comprises an amino acid sequence as set forth in SEQ ID NO: 127, and said LCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 142, 150, 151 and 152; preferably, said LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from the group consisting of: (1) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (1) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (2) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 150; (3) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 151; (4) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 152; (5) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; (6) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142; and (7) LCDR1: SEQ ID NO: 112, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 142. [Section 6] 6. The isolated antigen binding protein of any one of clauses 1 to 5, comprising an antibody light chain variable region VL, and wherein the VL comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 214, 217, 220, 223, 227-230, 232-234, 236, 237, 242, 243 and 244. [Section 7] 7. The isolated antigen binding protein of any one of clauses 1 to 6, comprising an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (3) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (4) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (5) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68; (6) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (7) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; (8) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 21, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (9) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (10) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (11) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; (12) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 150, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (13) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 151, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (14) LCDR1: SEQ ID NO: 106, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 152, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (15) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (16) LCDR1: SEQ ID NO: 107, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 68; (17) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (18) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (19) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 73; and (20) LCDR1: SEQ ID NO: 112, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65. [Section 8] 8. The isolated antigen-binding protein of any one of clauses 1 to 7, comprising an antibody heavy chain variable region VH and an antibody light chain variable region VL, wherein the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 214 and VH: SEQ ID NO: 169; (2) VL: SEQ ID NO: 217 and VH: SEQ ID NO: 172; (3) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 172; (4) VL: SEQ ID NO: 223 and VH: SEQ ID NO: 177; (5) VL: SEQ ID NO: 227 and VH: SEQ ID NO: 172; (6) VL: SEQ ID NO: 228 and VH: SEQ ID NO: 172; (7) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 181; (8) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 182; (9) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 183; (10) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 184; (11) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 185; (12) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 186; (13) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 187; (14) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 188; (15) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 189; (16) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 190; (17) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 191; (18) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 192; (19) VL: SEQ ID NO: 220 and VH: SEQ ID NO: 193; (20) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 172; (21) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 172; (22) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 172; (23) VL: SEQ ID NO: 233 and VH: SEQ ID NO: 172; (24) VL: SEQ ID NO: 234 and VH: SEQ ID NO: 172; (25) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 185; (26) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 191; (27) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 185; (28) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 188; (29) VL: SEQ ID NO: 230 and VH: SEQ ID NO: 191; (30) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 188; (31) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 191; (32) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 194; (33) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 195; (34) VL: SEQ ID NO: 236 and VH: SEQ ID NO: 194; (35) VL: SEQ ID NO: 236 and VH: SEQ ID NO: 195; (36) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 196; (37) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 197; (38) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 196; (39) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 197; (40) VL: SEQ ID NO: 229 and VH: SEQ ID NO: 188; (41) VL: SEQ ID NO: 232 and VH: SEQ ID NO: 185; (42) VL: SEQ ID NO: 242 and VH: SEQ ID NO: 172; (43) VL: SEQ ID NO: 243, and VH: SEQ ID NO: 172; and (44) VL: SEQ ID NO: 244, and VH: SEQ ID NO: 172. [Section 9] An isolated antigen binding protein comprising an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:22, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:367, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:368. [Section 10] 10. The isolated antigen binding protein of claim 9, wherein the HCDR1 comprises the amino acid sequence shown in SEQ ID NO: 22, the HCDR2 comprises the amino acid sequence shown in any one of SEQ ID NOs: 38 and 48, and the HCDR3 comprises the amino acid sequence shown in any one of SEQ ID NOs: 72, 80, 81, 82 and 83; preferably, wherein the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from the group consisting of: (1) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72, (2) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 80, (3) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 81, (4) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 80, (5) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 81, (6) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 82, and (7) HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 83. [Section 11] 11. The isolated antigen binding protein of any one of clauses 9 to 10, comprising an antibody heavy chain variable region VH, and wherein the VH comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 196 and 206-211. [Section 12] 12. The isolated antigen binding protein of any one of clauses 9 to 11, comprising an antibody light chain or a fragment thereof, said antibody light chain or a fragment thereof comprising LCDR1, LCDR2 and LCDR3, wherein said LCDR1 comprises the amino acid sequence set forth in SEQ ID NO:111, said LCDR2 comprises the amino acid sequence set forth in SEQ ID NO:127, and said LCDR3 comprises the amino acid sequence set forth in SEQ ID NO:142. [Section 13] 13. The isolated antigen binding protein of any one of clauses 9 to 12, comprising an antibody light chain variable region VL, and wherein said VL comprises the amino acid sequence shown in SEQ ID NO:237. [Section 14] 14. The isolated antigen binding protein of any one of clauses 9 to 13, comprising an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (2) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 80; (3) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 81; (4) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 80; (5) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 81; (6) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 82; and (7) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 83. [Section 15] 15. The isolated antigen-binding protein of any one of clauses 9 to 14, comprising an antibody heavy chain variable region VH and an antibody light chain variable region VL, wherein the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 196; (2) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 206; (3) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 207; (4) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 208; (5) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 209; (6) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 210; and (7) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 211. [Section 16] Full-length antibody, Fab, Fab', F(ab') 2 16. The isolated antigen binding protein of any one of claims 1 to 15, comprising an Fv, preferably an scFv, a di-scFv, a bispecific antibody, a multispecific antibody, a heavy chain antibody and / or a single domain antibody, or a monoclonal and / or polyclonal antibody produced by said antibody. [Section 17] 17. The isolated antigen binding protein of paragraph 16, wherein the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a humanized antibody, and a fully human antibody. [Section 18] 18. One or more isolated nucleic acid molecules encoding the isolated antigen binding protein of any one of paragraphs 1 to 17. [Section 19] A vector comprising the nucleic acid molecule according to item 18. [Section 20] A cell comprising the nucleic acid molecule of paragraph 18 or the vector of paragraph 19. [Section 21] 21. A method of producing the isolated antigen binding protein of any one of clauses 1 to 17, comprising culturing the cell of clause 20 under conditions allowing expression of the isolated antigen binding protein of any one of clauses 1 to 17. [Section 22] 18. A chimeric antigen receptor comprising the antigen-binding protein of any one of claims 1 to 17. [Section 23] 23. A genetically modified cell comprising the chimeric antigen receptor of claim 22, which is preferably a eukaryotic cell, preferably an isolated human cell, more preferably an immune cell such as a T cell or an NK cell. [Section 24] 18. An antibody drug conjugate comprising a cytotoxic agent and the antigen-binding protein of any one of clauses 1 to 17. [Section 25] A pharmaceutical composition comprising the isolated antigen binding protein of any one of clauses 1 to 17, the nucleic acid molecule of clause 18, the vector of clause 19, the cell of clause 20, the chimeric antigen receptor of clause 22, the genetically modified cell of clause 23, and / or the antibody drug conjugate of clause 24, and optionally a pharma- ceutical acceptable vector. [Section 26] The kit comprises the isolated antigen binding protein of any one of clauses 1 to 17, the nucleic acid molecule of clause 18, the vector of clause 19, the cell of clause 20, the chimeric antigen receptor of clause 22, the genetically modified cell of clause 23, the antibody drug conjugate of clause 24 and / or the pharmaceutical composition of clause 25; preferably the kit or administration device further comprises: (i) a device for administering the antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate and / or the pharmaceutical composition; and / or (ii) instructions for use. [Section 27] Use of the isolated antigen binding protein of any one of clauses 1 to 17, the nucleic acid molecule of clause 18, the vector of clause 19, the cell of clause 20, the chimeric antigen receptor of clause 22, the genetically modified cell of clause 23, the antibody drug conjugate of clause 24 and / or the pharmaceutical composition of clause 25 in the manufacture of a drug, wherein the drug is used for preventing, alleviating and / or treating a CCR8-mediated disease or disorder. [Section 28] 28. The use according to clause 27, wherein the CCR8-mediated disease or disorder comprises a tumor, and the tumor is preferably breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and / or colon cancer. [Section 29] 27. A method for inhibiting calcium ion influx by CCL1, the method comprising administering an isolated antigen binding protein according to any one of clauses 1 to 17 and / or a pharmaceutical composition according to clause 25, preferably an in vitro method or a method for non-diagnostic purposes. [Section 30] 27. A method of inhibiting CCL1-induced cell migration, the method comprising administering an isolated antigen binding protein according to any one of clauses 1 to 17 and / or a pharmaceutical composition according to clause 25, preferably an in vitro method or a method for non-diagnostic purposes. [Section 31] A method for preventing, alleviating, and / or treating a CCR8-mediated disease or disorder, the method comprising administering to a subject in need thereof the isolated antigen binding protein of any one of clauses 1 to 17, the nucleic acid molecule of clause 18, the vector of clause 19, the cell of clause 20, the chimeric antigen receptor of clause 22, the genetically modified cell of clause 23, the antibody drug conjugate of clause 24, and / or the pharmaceutical composition of clause 25. [Section 32] 32. The method of claim 31, wherein the CCR8-mediated disease or disorder comprises a tumor, and the tumor is preferably breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer, colon cancer.

[0101] Those skilled in the art can readily ascertain other aspects and advantages of the present application from the following detailed description. In the following detailed description, only exemplary embodiments of the present application are shown and described. Those skilled in the art will recognize that the present application allows those skilled in the art to modify the particular embodiments disclosed without departing from the spirit and scope of the present invention. Therefore, the descriptions set forth in the drawings and specification of the present application are intended to be illustrative rather than limiting. [Brief description of the drawings]

[0102] Particular features of the invention are set forth in the appended claims. A better understanding of the features and advantages of the invention can be obtained by reference to the following detailed description of exemplary embodiments and drawings, the description of which is brief: [Figure 1] Figures 1A, 1B, 1C and 1D show the results of CCR8 chimeric antibodies binding to human CCR8 on the cell surface: Figure 1A: CHO-K1, Figure 1B: HEK293, Figure 1C: Baf3, Figure 1D: CHO-K1. [Diagram 2] FIG. 2 shows the results of binding of a chimeric antibody with enhanced ADCC function and its parent antibody to human CCR8 on the surface of HEK293 cells. [Diagram 3] FIG. 3 shows the results of PR004128 mutant molecules binding to human CCR8 on the surface of CHO-K1 cells. [Figure 4] FIG. 4 shows the results of PR004128 humanized variants PR004519-PR004527 binding to human CCR8 on the surface of CHO-K1 cells. [Diagram 5] FIG. 5 shows the results of binding of PR004128 humanized mutants PR004668 and PR004669 to human CCR8 on the surface of CHO-K1 cells. [Figure 6] FIG. 6 shows the results of binding of PR004128PTM site-deleted and humanized mutant antibodies to human CCR8 on the surface of CHO-K1 cells. [Figure 7]7A, 7B and 7C show the results of fully human CCR8 antibodies binding to human CCR8 on the surface of CHO-K1 cells. [Figure 8] Figures 8A and 8B show the results of single cell clone fully human antibodies binding to human CCR8 on the surface of CHO-K1 cells. [Figure 9] FIG. 9 shows the results of binding of a saturation mutant antibody at position 96 of the light chain of RP004128 to human CCR8 on the surface of CHO-K1 cells. [Figure 10] Figures 10A and 10B show the results of PR004666 mutants binding to human CCR8 on the surface of CHO-K1 cells. [Figure 11] FIG. 11 shows the results of binding of PR006276AF, PR006276, PR006275AF, PR006275, PR005565AF, and PR005565 to human CCR8 on the surface of CHO-K1 cells. [Figure 12] FIG. 12 shows the results of chimeric antibodies binding to monkey CCR8 on the cell surface. [Figure 13] FIG. 13 shows the results of binding of a chimeric antibody with enhanced ADCC function to monkey CCR8 on the cell surface. [Figure 14] FIG. 14 shows the results of PR004128 mutant molecules binding to monkey CCR8 on the cell surface. [Figure 15] FIG. 15 shows the results of humanized antibodies PR004519-PR004527 binding to monkey CCR8 on the cell surface. [Figure 16] FIG. 16 shows the results of humanized antibodies PR004668 and PR004669 binding to monkey CCR8 on the cell surface. [Figure 17] FIG. 17 shows the results of PTM site-removed humanized antibodies binding to monkey CCR8 on the cell surface. [Figure 18] FIG. 18 shows the results of binding of a saturation mutant antibody at position 96 of the light chain of RP004128 to monkey CCR8 on the cell surface. [Figure 19] FIG. 19 shows the results of PR004666 mutants binding to monkey CCR8 on the cell surface. [Figure 20]Figure 20 shows the results of PR006276AF, PR006276, PR006275AF, PR006275, PR005565AF, and PR005565 binding to monkey CCR8 on the cell surface. [Figure 21] Figures 21A and 21B show the results of CCR8 chimeric antibody molecules blocking intracellular calcium flux induced by CCL1. [Figure 22] FIG. 22 shows the results of PR005329, PR005330, PR005332, and PR005333 blocking CCL1-induced intracellular calcium flux. [Figure 23] FIG. 23 shows the results of PR004121, PR004122, PR004225, PR004128, PR004131, PR004249, PR004250, PR004251, and PR004252 blocking CCL1-induced intracellular calcium flux. [Figure 24] FIG. 24 shows the results of PR004668, PR004520, PR004669, and PR004525 blocking CCL1-induced intracellular calcium flux. [Diagram 25] Figure 25 shows the results of PR004660, PR004661, PR004662, PR004663, PR004664, PR004665, PR004666, PR004667, and PR004128 blocking CCL1-induced intracellular calcium flux. [Figure 26] FIG. 26 shows the results of PR005124, PR005125, PR005127, PR005128, and PR004128 blocking CCL1-induced intracellular calcium flux. [Figure 27] FIG. 27 shows the results of PR005170, PR005171, and PR005172 blocking CCL1-induced intracellular calcium flux. [Figure 28]Figure 28A shows the results of PR004120, PR004121, PR004122, PR004123, PR004124, and PR004125 blocking CCL1-induced cell migration. Figure 28B shows the results of PR004126, PR004127, PR004128, PR004130, PR004129, and PR004131 blocking CCL1-induced cell migration. [Figure 29] Figure 29 shows the results of PR005329, PR005330, PR005332, PR005333, and PR004520 blocking CCL1-induced cell migration. [Diagram 30] Figure 30A shows the results of PR004121, PR004122, PR004125, PR004128, PR004131, PR004250, and PR004251 blocking CCL1-induced cell migration. Figure 30B shows the results of PR004525 blocking CCL1-induced cell migration. Figure 30C shows the results of PR004249 blocking CCL1-induced cell migration. [Diagram 31] Figure 31A shows the results of PR004324, PR004326, PR004328, PR004329, and PR004128 blocking CCL1-induced cell migration. Figure 31B shows the results of PR004336, PR004339, PR004340, PR004343, and PR004128 blocking CCL1-induced cell migration. Figure 31C shows the results of PR004330, PR004333, and PR004128 blocking CCL1-induced cell migration. [Diagram 32] Figure 32A shows the results of PR004519, PR004520, PR004521, PR004522, PR004523, PR004524, and PR004128 blocking CCL1-induced cell migration. Figure 32B shows the results of PR004525, PR004526, PR004527, and PR004128 blocking CCL1-induced cell migration. Figure 32C shows the results of PR004668 and PR004669 blocking CCL1-induced cell migration. [Diagram 33] FIG. 33 shows the results of PR004662 and PR004666 blocking CCL1-induced cell migration. [Diagram 34] Figure 34A shows the results of PR005124, PR005125, PR005127, PR005128, and PR004128 blocking CCL1-induced cell migration, and Figure 34B shows the results of PR005331, PR005335, PR005336, and PR004520 blocking CCL1-induced cell migration. [Diagram 35] Figures 35A, 35B, 35C, 35D and 35E show the results of antigen epitope competitive binding measurements of PR004121, PR004122, PR004125, PR004128 and PR004131. [Diagram 36] FIG. 36 shows the results of measuring the ADCC reporter gene biological activity of PR004125 and PR004250. [Figure 37] FIG. 37 shows the results of measuring the ADCC reporter gene biological activity of PR005565AF, PR006275AF, and PR006276AF. [Figure 38] Figure 38A shows the results of measuring PR004668, PR004520, PR004669, and PR004525 dependent NK cell-mediated ADCC biological activity. Figure 38B shows the results of measuring PR004519 dependent NK cell-mediated ADCC biological activity. Figure 38C shows the results of measuring PR004666 dependent NK cell-mediated ADCC biological activity. Figure 38D shows the results of measuring PR005125 and PR005128 dependent NK cell-mediated ADCC biological activity. Figure 38E shows the results of measuring PR004974 dependent NK cell-mediated ADCC biological activity. [Figure 39] FIG. 39 shows the results of measuring PR004666, PR006155, and PR006166-dependent NK cell-mediated ADCC biological activity. [Diagram 40] FIG. 40 shows the results of measuring the differential expression of CCR8 in Tregs derived from human tumor-infiltrating lymphocytes (ccRCC TIL Tregs and BC TIL Tregs) and Tregs derived from normal human PBMCs. [Diagram 41]Figures 41A and 41B show that PR005565 (Figure 41A) and a commercial CCR8 antibody (Biolegend, Cat N360602) (Figure 41B) bind to cells overexpressing CCR8. [Diagram 42] Figure 42 shows tumor growth inhibition by PR004520 and anti-PD-1 antibody, and anti-PD-L1 antibody Tecentrip, alone or in combination. [Diagram 43] Figure 43 shows tumor growth inhibition by PR004520, PR004525, PR004668 and anti-PD-1 antibody alone or in combination. [Diagram 44] Figure 44 shows that the defucosylated form of PR005565AF and the anti-PD-1 antibody RMP1-14, anti-PD-L1 antibody, alone or in combination, inhibit tumor growth, where ip: intraperitoneal injection, BIWx6: twice a week for 6 doses. [Diagram 45] FIG. 45 shows that defucosylated forms of PR005565AF, PR006276AF, PR006275AF inhibit tumor growth at 3 mg / kg, 10 mg / kg, ip: intraperitoneal injection, BIW×6: twice weekly for 6 doses. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0103] Detailed Description Hereinafter, the embodiments of the present invention will be described with reference to specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0104] Term definition In this application, the term "antigen binding protein" generally refers to a protein that includes an antigen-binding portion, optionally adopting a conformational stent or scaffold portion that facilitates binding of the antigen-binding protein to an antigen. Typically, it can include an antibody light chain variable region (VL), an antibody heavy chain variable region (VH), or both. The VH and VL regions can be further differentiated into hypervariable regions called complementarity determining regions (CDRs) interspersed with more conservative regions called framework regions (FRs or FWRs). Each VH and VL may be composed of three CDRs and four FR regions, arranged from the amino terminus to the carboxyl terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. The variable regions of the heavy and light chains include the binding domains that interact with the antigen. Examples of antigen-binding proteins include, but are not limited to, antibodies, antigen-binding fragments (Fab, Fab', Fv fragments, F(ab')2, scFv, di-scFv and / or dAb), antibody-drug conjugates, multispecific antibodies (e.g., bispecific antibodies), antibody fragments, antibody derivatives, antibody analogs, or fusion proteins, so long as they exhibit the desired antigen-binding activity.

[0105] In this application, the term "Fab" generally refers to a fragment containing a heavy chain variable domain and a light chain variable domain, and also contains the constant domain of the light chain and the first constant domain (CH 1) of the heavy chain; the term "Fab'" generally refers to a fragment that differs from Fab by the addition of a small number of residues (including one or more cysteines from the antibody hinge region) at the carboxyl terminus of the heavy chain CH1 domain; the term "F(ab')2" generally refers to a dimer of Fab', an antibody fragment that contains two Fab fragments linked via disulfide bridges on the hinge region. The term "Fv" generally refers to the minimum antibody fragment that contains a complete antigen recognition and binding site. In some cases, the fragment may consist of a dimer of a heavy chain variable region and a light chain variable region that are tightly associated non-covalently; the term "dsFv" generally refers to a disulfide bond-stabilized Fv fragment in which the bond between a single light chain variable region and a single heavy chain variable region is a disulfide bond. The term "dAb fragment" generally refers to an antibody fragment that consists of a VH domain. In this application, the term "scFv" generally refers to a monovalent molecule formed by covalently linking one heavy chain variable domain and one light chain variable domain of an antibody by a flexible peptide linker; such scFv molecules can have the general structures NH2-VL-linker-VH-COOH or NH2-VH-linker-VL-COOH.

[0106] In this application, the term "variable" generally refers to the fact that there is strong variation in some parts of the sequence of the variable domain of an antibody, which shapes the binding and specificity of various specific antibodies to a particular antigen. However, the variability is not uniformly distributed throughout the variable region of an antibody. It is concentrated in three segments of the light and heavy chain variable regions, called the complementarity determining regions (CDRs) or hypervariable regions (HVRs). The more highly conserved parts of the variable regions are called frameworks (FRs). Natural heavy and light chain variable domains each contain four FR regions (H-FR1, H-FR2, H-FR3, H-FR4, L-FR1, L-FR2, L-FR3, L-FR4), which mostly adopt a β-fold structure, connected by three CDRs, forming loop connections and sometimes forming part of the β-fold structure. The CDRs in each chain are adjacent to each other through the FR region and form the antigen-binding site of the antibody together with the CDR from the other chain, and the constant region is not directly involved in the binding of the antibody to the antigen, but exhibits different effect functions such as antibody-dependent cellular cytotoxicity of the antibody. In the art, the CDR of an antibody can be defined in various ways, such as the Kabat definition rule based on sequence variability (see Kabat et al., Immunological Protein Sequence, 5th Edition, National Institutes of Health, Bethesda, MD (1991)) and the Chothia definition rule based on the position of the structural ring region (see A1-Lazikani et al., JmolBiol 273:927-481997). In the present application, the combined definition rule, including the Kabat definition and the Chothia definition, is also used to determine the amino acid residues in the variable domain sequence and the full-length antibody sequence. See Table 1 for the definition method of the antibody CDR. [Table 1]

[0107] Here, Laa-Lbb can refer to the amino acid sequence from position aa (Chothia numbering scheme) to position bb (Chothia numbering scheme) from the N-terminus of the antibody light chain, and Haa-Hbb can refer to the amino acid sequence from position aa (Chothia numbering scheme) to position bb (Chothia numbering scheme) from the N-terminus of the antibody heavy chain. For example, L24-L34 can refer to the amino acid sequence from position 24 to position 34 from the N-terminus of the antibody light chain according to the Chothia numbering scheme, and H26-H32 can refer to the amino acid sequence from position 26 to position 32 from the N-terminus of the antibody heavy chain according to the Chothia numbering scheme. For example, in the present application, CDR division can be performed using the Chothia numbering scheme as an example.

[0108] As used herein, the term "isolated" antigen binding protein generally refers to an antigen binding protein that has been identified and isolated and / or recovered from components of its production environment (e.g., natural or recombinant). The contaminant components of its production environment may typically include enzymes, hormones, other proteinaceous or non-proteinaceous solutes, substances that would interfere with its research, diagnostic or therapeutic uses. An isolated antigen binding protein or antibody is usually prepared by at least one purification step.

[0109] In this application, the term "monoclonal antibody" generally refers to an antibody obtained from a population of substantially homogeneous antibodies, where the individual antibodies within the cluster are identical, except for minor natural mutations that may be present. Monoclonal antibodies usually have a high degree of specificity for a single antigen site. Also, unlike traditional polyclonal antibody preparations (which usually have different antibodies against different determinant clusters), each monoclonal antibody is against a single determinant cluster on the antigen. In addition to their specificity, the advantage of monoclonal antibodies is that they can be synthesized by hybridoma culture, uncontaminated by other immunoglobulins. The term "monoclonal" refers to the character of an antibody obtained from a substantially homogeneous antibody population, and is not to be construed as requiring the antibody to be produced by any particular method. For example, the monoclonal antibodies used in accordance with the present invention can be prepared in hybridoma cells or by recombinant DNA methods.

[0110] In this application, the term "chimeric antibody" generally refers to an antibody whose variable region is derived from one species and whose constant region is derived from another species. Typically, the variable region is derived from an antibody of a laboratory animal such as a rodent (the "parent antibody"), and the constant region is derived from a human antibody, such that the resulting chimeric antibody is less likely to provoke an adverse immune response in a human individual compared to the parent (e.g., mouse-derived) antibody.

[0111] In this application, the term "humanized antibody" generally refers to an antibody in which all or part of the amino acids other than the CDR regions of a non-human antibody (e.g., a murine antibody) have been replaced by the corresponding amino acids from a human immunoglobulin. Small additions, deletions, insertions, substitutions or modifications of amino acids in the CDR regions may be tolerated as long as the antibody retains the ability to bind to a particular antigen. A humanized antibody may optionally include at least a portion of a human immunoglobulin constant region. A "humanized antibody" retains antigen specificity similar to that of the original antibody. "Humanized" forms of non-human (e.g., murine) antibodies may include, at a minimum, chimeric antibodies of non-human immunoglobulin-derived sequences. In some cases, CDR region residues in a human immunoglobulin (acceptor antibody) may be replaced by CDR region residues of a non-human species (donor antibody) (mouse, rat, rabbit, or non-human primate) having the desired properties, affinities, and / or capabilities. In some cases, FR region residues of a human immunoglobulin may be replaced by the corresponding non-human residues. In addition, a humanized antibody may contain amino acid modifications not present in the acceptor antibody or in the donor antibody. These modifications can be made to further refine antibody performance, such as binding affinity.

[0112] In this application, the term "fully human antibody" generally refers to an antibody that is expressed in a genetically engineered animal lacking an antibody gene by transferring a gene encoding a human antibody. All parts of the antibody (including the variable and constant regions of the antibody) are encoded by genes of human origin. Fully human antibodies can greatly reduce immune side reactions in the human body caused by foreign antibodies. Methods for obtaining fully human antibodies in the art include phage display technology, transgenic mouse technology, ribosome display technology, and RNA-polypeptide technology.

[0113] In this application, the term "specific binding" generally means that an antibody binds to an epitope through its antigen-binding domain, and the binding requires some complementarity between the antigen-binding domain and the epitope. According to this definition, an antibody is said to "specifically bind" if it prefers to bind to an epitope through its antigen-binding domain rather than to a random, unrelated epitope. "Epitope" refers to a specific atomic group (e.g., sugar side chain, phosphonyl group, sulfonyl group) or amino acid on an antigen that binds to an antigen-binding protein (e.g., an antibody).

[0114] As used herein, the terms "KD", "K D " are used interchangeably and usually refer to the equilibrium dissociation constant, and "KD" is the ratio of the dissociation rate constant (kdis, also called "off-rate (koff)" or "kd") to the association rate constant (kon, also called "association rate (kon)" or "ka"). The binding affinity of an antigen-binding protein (e.g., an antibody) to an antigen can be expressed using the association rate constant (kon), the dissociation rate constant (kdis), and the equilibrium dissociation constant (KD). Methods for determining the association and dissociation rate constants are well known in the art, including, but not limited to, biomembrane interference technology (BLI), radioimmunoassay (RIA), equilibrium dialysis, surface plasmon resonance (SPR), fluorescence resonance energy transfer (FRET), co-immunoprecipitation (Co-IP), and protein chip technology. The affinity of a particular protein-protein interaction being measured may differ when measured under different conditions (e.g., salt concentration, pH).

[0115] As used herein, the term "primate" refers generally to monkey and ape species, and includes monkey species such as those from the genus Macaque (e.g., specifically, Macaca fascicularis and Macaca mulatta), and baboons (Papio ursinus), as well as common marmosets (species from the genus Callithrix), squirrel monkeys (species from the genus Saimili), tamarind monkeys (species from the genus Saguinus), and monkey species such as chimpanzees (Pan troglodytes), and also includes Homo sapiens.

[0116] In this application, the term "epitope" generally refers to a portion or region of an antigen to which an antigen-binding protein, such as an antibody, specifically binds. An epitope is usually composed of a group of chemically active interfaces, such as amino acids or carbohydrate or sugar side chain molecules, and generally has specific three-dimensional structural characteristics and specific charge characteristics. An epitope can be a linear epitope or a structural epitope. In a linear epitope, all interaction points between the protein and the interacting molecule (such as an antibody) occur linearly along the primary amino acid sequence of the protein. In a structural epitope, the interaction points occur across amino acids on the protein that are separated from each other. Methods to determine which epitopes an antigen-binding protein, such as an antibody, binds to (such as Epitope Mapping) are known in the art and include, for example, immunoimprinting and immunoprecipitation assays, for example, testing the reactivity of overlapping or adjacent peptides (e.g., from CCR8) with a particular antigen-binding protein (e.g., an anti-CCR8 antibody). Methods to determine epitope spatial conformation include techniques in the art and as described herein, for example, x-ray diffraction, 2-dimensional nuclear magnetic resonance, and HDX-MS.

[0117] As used herein, the term "cross-reactivity" refers to the ability of an antigen binding protein described herein to bind to CCR8 from different species. For example, in some cases, an antigen binding protein that binds to human CCR8 can also bind to CCR8 from other species (e.g., cynomolgus monkey CCR8). As used herein, cross-reactivity can be measured by detecting specific reactivity with purified antigen in a binding assay (e.g., SPR, ELISA, or FACS), or by detecting binding or functional interaction with cells that physiologically express CCR8. Methods for measuring cross-reactivity include standard binding measurements as described herein, for example, by using flow cytometry techniques.

[0118] As used herein, the term "subject" generally refers to mammals, including, but not limited to, domestic animals (e.g., cows, sheep, cats, dogs, horses), primates (e.g., humans and non-human primates, such as monkeys), rabbits, and rodents (e.g., mice and rats).

[0119] As used herein, the term "nucleic acid molecule" generally refers to an isolated form of nucleotides, deoxyribonucleotides, or ribonucleotides or analogs thereof of any length, either isolated from their natural environment or artificially synthesized.

[0120] In this application, the term "vector" refers to a nucleic acid molecule that is typically capable of self-replicating in a suitable host and transferring an inserted nucleic acid molecule into and / or between host cells. Vectors can include vectors primarily for inserting DNA or RNA into cells, vectors primarily for replicating DNA or RNA, and vectors primarily for transcriptional and / or translational expression of DNA or RNA. The vectors further include vectors with multiple functions as described above. The vector may be a polynucleotide that can be transcribed and translated into a polypeptide upon introduction into a suitable host cell. Generally, the vector can be caused to produce a desired expression product by culturing a suitable host cell containing the vector.

[0121] As used herein, the term "cell" generally refers to a plasmid or vector that contains or may contain a nucleic acid molecule described herein, or an individual cell, cell line, or cell culture that is capable of expressing an antibody or antigen-binding fragment thereof described herein. The cell may include offspring of a single host cell. Due to natural, unexpected, or significant mutations, the offspring and the original parent cell may not necessarily be completely identical in morphology or genomically, but may be capable of expressing an antibody or antigen-binding fragment thereof described herein. The cell may be obtained by in vitro transfecting the cell with a vector described herein. The cell may be a prokaryotic cell (e.g., E. coli) or a eukaryotic cell (e.g., a yeast cell, such as a COS cell, a Chinese hamster ovary (CHO) cell, a HeLa cell, a HEK293 cell, a COS-1 cell, a NS0 cell, or a myeloma cell). In some cases, the cell may be a mammalian cell. For example, the mammalian cell may be a CHO-K1 cell. As used herein, the term "recombinant cell" generally refers to a cell into which a recombinant expression vector has been introduced. Recombinant host cells include not only the particular cells but also the progeny of those cells.

[0122] In this application, the term "pharmaceutical composition" generally refers to a formulation in which the biological activity of the active ingredient is present in a form that is effective and does not contain additional ingredients that are unacceptably toxic to the subject to which the composition is administered. The composition is sterile. A "sterile" composition is one that has been sterilized or is free of all live microorganisms and their spores.

[0123] As used herein, the term "pharmaceutically acceptable vector" generally includes pharma- ceutically acceptable vectors, excipients, or stabilizers, the amounts and concentrations of which are non-toxic to the cells or mammals to which they are exposed. Generally, physiologically acceptable vectors are pH-buffered aqueous solutions. Examples of physiologically acceptable vectors include buffers, antioxidants, low molecular weight (less than about 10 residues) polypeptides, proteins, hydrophilic polymers, amino acids, monosaccharides, disaccharides, and other carbohydrates, chelating agents, sugar alcohols, salt-forming counterions, such as sodium, and / or non-ionic surfactants.

[0124] In this application, the term "treatment" generally means that it is expected to change the natural disease history of the individual being treated, and can realize a clinical intervention that is performed during prophylaxis or clinical pathology. The therapeutic effect, as required, includes, but is not limited to, preventing the occurrence or recurrence of the disease, relieving symptoms, attenuating the direct or indirect pathological consequences of the disease, preventing metastasis, reducing the rate of disease progression, improving or alleviating the disease state, and alleviating or improving the prognosis. In some cases, the antibody (e.g., anti-CCR8 antibody) can be used to delay or slow the progression of the disease.

[0125] As used herein, the term "tumor" generally refers to all proliferation and growth of cells, whether malignant or benign, and all pre-cancerous and cancerous cells and tissues. As used herein, tumors can include solid and / or non-solid tumors (e.g., hematological tumors, lymphomas).

[0126] As used herein, the term "antibody drug conjugate" generally refers to a substance formed by conjugating an antigen-binding protein to another active agent, which may be a small molecule active agent such as a chemotherapeutic agent, a toxin, an immunotherapeutic agent, an imaging probe, or a spectral probe.

[0127] As used herein, the term "kit" generally refers to a packaged product containing components for administering an antigen binding protein of the present application to treat a PD-1 mediated related disorder. The components of the kit may be contained in separate vials (i.e., a kit with separate parts) or may be provided in a single vial. The kit may include reagents such as buffers, protein stabilizers, signal producing systems (e.g., fluorescent signal producing systems), antibodies, control proteins, and test containers. The kit may also include instructions for carrying out the method.

[0128] In this application, the term "administration device" refers to (i) an injection module for administering a pharmaceutical composition comprising an active ingredient to a subject, (ii) a pharmaceutical composition for infusion comprising an active ingredient selected from the group consisting of antigen binding proteins, multispecific antibodies, immune cells, antibody drug conjugates, or combinations thereof, and (iii) an optional drug efficacy monitoring module.

[0129] As used herein, the term "combination" generally means that two or more therapeutic agents can be administered conjointly to a subject in a mixture, simultaneously as a single agent, or sequentially in any order as a single agent.

[0130] In the present specification, the term "between" generally means that the C-terminus of an amino acid fragment is directly or indirectly connected to the N-terminus of a first amino acid fragment, and the N-terminus is directly or indirectly connected to the C-terminus of a second amino acid fragment. In the light chain, for example, the N-terminus of the L-FR2 is directly or indirectly connected to the C-terminus of LCDR1, and the C-terminus of the L-FR2 is directly or indirectly connected to the N-terminus of LCDR2. Also, for example, the N-terminus of the L-FR3 is directly or indirectly connected to the C-terminus of LCDR2, and the C-terminus of the L-FR3 is directly or indirectly connected to the N-terminus of LCDR3. In the heavy chain, for example, the N-terminus of the H-FR2 is directly or indirectly connected to the C-terminus of HCDR1, and the C-terminus of the H-FR2 is directly or indirectly connected to the N-terminus of HCDR2. Also, for example, the N-terminus of the H-FR3 is directly or indirectly connected to the C-terminus of HCDR2, and the C-terminus of the H-FR3 is directly or indirectly connected to the N-terminus of HCDR3. In the present application, the "first amino acid fragment" and the "second amino acid fragment" may be any amino acid fragments that are the same or different.

[0131] In this application, the term "CCR8" may also be referred to as CY6, CKR-L1, CDw198, CMKBR8, GPRCY6, CMKBRL2, CC-CKR-8, or TER1, and refers to a G protein-conjugated seven-transmembrane CC chemokine receptor protein that is usually expressed in the thymus, spleen, etc., and belongs to the beta chemokine receptor family. Chemokines and their receptors are important for the migration of various cell types to sites of inflammation. CCL1 (or I-309), thymus activation-regulating cytokine (TARC), and macrophage inflammatory protein 1Beta (MIP-1Beta) have been identified as ligands for CCR8. Studies of CCR8 and its ligands have revealed that they help regulate the chemokine activity of mononuclear cells and the apoptosis of thymocytes. The term "CCR8" includes any native CCR8 from any vertebrate, including mammals such as primates (e.g., humans and monkeys) and rodents (e.g., mice and rats). CCR8 also includes "full-length", unprocessed CCR8, and any form of CCR8 produced by processing in cells. CCR8 can exist as a transmembrane protein or as a soluble protein. The term also encompasses naturally occurring variants of CCR8, such as splice variants or allelic variants. CCR8 sequences are known in the art. For example, information regarding the human CCR8 gene (including genomic DNA sequence) can be found at NCBI Gene ID No. 1237. Also, for example, information regarding the cynomolgus CCR8 gene, including genomic DNA sequence, can be found at NCBI Gene ID No. 10213257. An exemplary full-length human CCR8 protein amino acid sequence can be found at NCBI Accession No. NP_005192.1. An exemplary full-length cynomolgus CCR8 protein sequence can be found at NCBI Accession No. NP_001274549.

[0132] In the present application, the term "CCL1", also known as P500, SISe, TCA3, I-309 or SCYA1, belongs to the chemokine CC subfamily, participates in immune regulation and inflammatory processes, and can bind to CCR8. CCL1 is normally secreted by activated T cells and exhibits chemokine activity on mononuclear cells. The term "CCL1" includes any naturally occurring CCL1 from any vertebrate source, including mammals such as primates (e.g., humans and monkeys) and rodents (e.g., mice and rats). The CCL1 also includes "full-length", unprocessed CCL1, and any form of CCL1 produced by processing in cells. CCL1 may exist as a transmembrane protein or a soluble protein. The term also encompasses naturally occurring variants of CCL1, such as splice variants or allelic variants. CCL1 sequences are known in the art. For example, information regarding the human CCL1 gene (including genomic DNA sequence) can be found at NCBI Gene ID No. 6346. The amino acid sequence of an exemplary full-length human CCL1 protein can be found at NCBI accession number NP_002972.1.

[0133] In this specification, the term "comprise" generally means to include, encompass, contain or comprise. In some cases, it may also mean to include or consist of.

[0134] In this application, the term "about" generally means varying within 0.5%-10% above or below a specified value, for example, varying within 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10% above or below a specified value.

[0135] Detailed Description of the Invention Antigen-binding proteins In one aspect, the present application provides an isolated antigen binding protein having one or more of the following properties: 1) In ELISA detection, for example, 2 × 10 -8 can bind to primate-derived CCR8 with an EC50 value of M or lower; 2) It can block the binding of CCR8 to the ligand CCL1; 3) It can inhibit calcium ion influx induced by CCR8; and 4) It can inhibit CCR8-induced cell migration.

[0136] In the present application, the Fc region of the antigen binding protein may comprise modifications to enhance the ADCC effect.

[0137] Optionally, the antigen binding protein is capable of binding CCR8 of human and / or monkey origin.

[0138] In some cases, the antigen binding protein is capable of binding CCR8 from both human and monkey.

[0139] In some cases, the antigen binding protein specifically targets Treg cells with immunosuppressive activity infiltrated into tumor tissue.

[0140] Optionally, the antigen binding protein does not have targeting to inflammatory Treg cells and non-Treg type T cells.

[0141] In the present application, the isolated antigen binding protein can comprise at least one CDR of an antibody heavy chain variable region VH, for example, the VH can comprise an amino acid sequence set forth in any of SEQ ID NOs: 169, 172, 177, and 181-197.

[0142] In the present application, the antigen binding protein may comprise an HCDR1, wherein the HCDR1 may comprise the amino acid sequence shown in SEQ ID NO:359: GFTFX5TX7 (SEQ ID NO:359); where X5=N, Q or S, and X7=N or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the HCDR1 may comprise the amino acid sequence shown in any one of SEQ ID NOs: 15, 16, 21, and 22.

[0143] In the present application, the antigen binding protein may comprise an HCDR2, and the HCDR2 may comprise the amino acid sequence shown in SEQ ID NO: 38. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0144] In the present application, the antigen binding protein may comprise an HCDR3, wherein the HCDR3 may comprise the amino acid sequence shown in SEQ ID NO:360: GKEX4X5NYYAMDX 12 (SEQ ID NO:360); where X4=N or Q, X5=A or G, X 12 = F or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the HCDR3 may comprise the amino acid sequence shown in any of SEQ ID NOs: 65, 68, 72, and 73.

[0145] In the present application, the antigen binding protein may comprise HCDR1, HCDR2, and HCDR3, which may comprise, in order, the amino acid sequences set forth in SEQ ID NO:359, SEQ ID NO:38, and SEQ ID NO:360, respectively. In some cases, HCDR1 of the antigen binding protein may comprise the amino acid sequence set forth in any of SEQ ID NOs:15, 16, 21, and 22, the HCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:38, and the HCDR3 may comprise the amino acid sequence set forth in any of SEQ ID NOs:65, 68, 72, and 73. For example, the antigen binding protein may comprise HCDR1, HCDR2, and HCDR3, and the combination of HCDR1, HCDR2, and HCDR3 may be selected from any of the groups in the following table: [Table 2]

[0146] In the present application, the antigen binding protein may comprise a framework region H-FR1. The C-terminus of the H-FR1 is directly or indirectly connected to the N-terminus of the HCDR1. For example, the H-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs: 1, 2, 5, 7 and 8. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0147] In the present application, the antigen binding protein may comprise an H-FR2, wherein the H-FR2 is between the HCDR1 and the HCDR2. For example, the H-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 26, 27, 30, and 31. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0148] In the present application, the antigen binding protein may comprise an H-FR3, wherein the H-FR3 is between the HCDR2 and the HCDR3, for example, the H-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 50, 56, and 57. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0149] In the present application, the antigen binding protein may comprise an H-FR4, and the N-terminus of the H-FR4 may be linked to the C-terminus of the HCDR3. For example, the H-FR4 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 84, 85, and 89. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0150] In the present application, the antigen binding protein may comprise a heavy chain variable region VH, and the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 169, 172, 177 and 181-197. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0151] In the present application, the antigen binding protein may comprise an Fc region, for example, the Fc region may comprise a modification to enhance ADCC effect.

[0152] In the present application, the antigen binding protein may comprise an Fc region, for example, the glycosylated side chain of the Fc region may be free of a fucose group, or the Fc region may be free of a glycosylated side chain of a fucose group.

[0153] The antigen binding protein of the present application may comprise a heavy chain constant region CH, and the antibody heavy chain constant region may comprise a human IgG constant region. Optionally, the human IgG constant region may comprise a human IgG1 constant region. The human IgG1 constant region may comprise natural and synthetic IgG1 constant regions or variants thereof. The mutations may comprise one or more of the following mutations: S239D and I332E. For example, the human IgG1 constant region of the fusion protein may comprise the amino acid sequence shown in SEQ ID NO:356 or 357.

[0154] In the present application, the antigen binding protein can comprise an antibody heavy chain. For example, the antibody heavy chain can comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 251, 254, 259-262, 266-284.

[0155] In the present application, the antigen binding protein may comprise at least one CDR in an antibody light chain variable region VL, wherein the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 214, 217, 220, 223, 227-230, 232-234, 236, 237, 242, 243 and 244.

[0156] In the present application, the antigen binding protein can comprise an LCDR1, and the LCDR1 can comprise the amino acid sequence shown in SEQ ID NO:361: RSX3KSLLHSX 10 X 11 X 12 X 13 YLY (SEQ ID NO: 361); in which X3=N or S; X 10 =N or Q;X 11 =A or G;X 12 =N or K; and X 13 = I or T. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0157] For example, the LCDR1 may comprise the amino acid sequence set forth in any one of SEQ ID NOs:105, 106, 107, 111, and 112.

[0158] In the present application, the antigen binding protein may comprise an LCDR2, and the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO: 127. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0159] In the present application, the antigen binding protein may comprise an LCDR3, and the LCDR3 may comprise the amino acid sequence shown in SEQ ID NO:362: MQHLEYPX8T (SEQ ID NO:362); where X8=I, L, M or V. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0160] For example, the LCDR3 may comprise the amino acid sequence set forth in any one of SEQ ID NOs:142, 150, 151, and 152.

[0161] In the present application, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, in which the LCDR1 may comprise the amino acid sequence shown in any one of SEQ ID NOs: 105, 106, 107, 111 and 112, the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO: 127, and the LCDR3 may comprise the amino acid sequence shown in SEQ ID NO: 362.

[0162] In the present application, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, in which the LCDR1 may comprise the amino acid sequence shown in SEQ ID NO:361, the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO:127, and the LCDR3 may comprise the amino acid sequence shown in any one of SEQ ID NOs:142, 150, 151 and 152.

[0163] For example, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, and the combination of LCDR1, LCDR2 and LCDR3 may be selected from any of the groups in Table 3 below. [Table 3]

[0164] In the present application, the antigen binding protein may comprise a framework region L-FR1. The C-terminus of the L-FR1 is directly or indirectly connected to the N-terminus of the LCDR1. For example, the L-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs:92, 98 and 99. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0165] In the present application, the antigen binding protein may comprise an L-FR2, wherein the L-FR2 is between the LCDR1 and the LCDR2. For example, the L-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 118, 122, and 123. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0166] In the present application, the antigen binding protein may comprise an L-FR3, said L-FR3 being between said LCDR2 and said LCDR3, for example, said L-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 135-136, for example, said sequence may be a sequence determined based on the Chothia definition rules.

[0167] In the present application, the antigen binding protein may comprise an L-FR4, and the N-terminus of the L-FR4 may be linked to the C-terminus of the LCDR3. For example, the L-FR4 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 156, 158, 159 and 164. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0168] In the present application, the antigen binding protein may comprise a light chain variable region VL, and the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 214, 217, 220, 223, 227-230, 232-234, 236, 237, 242, 243, and 244. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0169] The antigen binding protein of the present application may comprise a light chain constant region CL, and the antibody light chain constant region may comprise a human Igκ constant region. For example, the CL region may comprise the amino acid sequence shown below: SEQ ID NO:358.

[0170] In the present application, the antigen binding protein can comprise an antibody light chain. For example, the antibody light chain can comprise an amino acid sequence as set forth in any one of SEQ ID NOs:321, 324, 327, 330, 334-337, 339-341, 343, 344, 349, 350, and 351.

[0171] In the present application, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise the amino acid sequences set forth in SEQ ID NO:359, SEQ ID NO:38, SEQ ID NO:360, SEQ ID NO:361, SEQ ID NO:127 and SEQ ID NO:362, respectively.

[0172] In some cases, the HCDR1 of the antigen binding protein may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 15, 16, 21, and 22; the HCDR2 may comprise an amino acid sequence as set forth in SEQ ID NO: 38; and the HCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 65, 68, 72, and 73; the LCDR1 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 105, 106, 107, 111, and 112; the LCDR2 may comprise an amino acid sequence as set forth in SEQ ID NO: 127; and the LCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 142, 150, 151, and 152.

[0173] For example, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the combination of HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may be selected from any group in Table 4 below. [Table 4]

[0174] In the present application, the antigen binding protein may comprise an antibody heavy chain variable region (VH) and light chain variable region (VL). For example, the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 169, 172, 177, and 181-197, and the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 214, 217, 220, 223, 227-230, 232-234, 236, 237, 242, 243, and 244.

[0175] For example, the VL and VH combination of the antigen binding protein may comprise any group selected from Table 5 below. [Table 5]

[0176] In the present application, the antigen binding protein may include an antibody light chain and an antibody heavy chain, in which the light chain may include an amino acid sequence as set forth in any one of SEQ ID NOs: 321, 324, 327, 330, 334-337, 339-341, 343, 344, 349, 350, and 351, and the heavy chain may include an amino acid sequence as set forth in any one of SEQ ID NOs: 251, 254, 259-262, 266-284.

[0177] For example, the light and heavy chain combination of the antigen binding protein may comprise any group selected from Table 6 below. [Table 6]

[0178] In the present application, the antigen binding protein may comprise at least one CDR in an antibody heavy chain variable region VH. For example, the VH may comprise an amino acid sequence shown in any one of SEQ ID NOs: 196 and 206-211.

[0179] In the present application, the antigen binding protein may comprise an HCDR1, and the HCDR1 may comprise the amino acid sequence shown in SEQ ID NO: 22. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0180] In the present application, the antigen binding protein may comprise an HCDR2, and the HCDR2 may comprise the amino acid sequence shown in SEQ ID NO:367: RSKSNX6YA (SEQ ID NO:367); wherein X6=N or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0181] For example, the HCDR2 may comprise the amino acid sequence shown in any one of SEQ ID NOs:38 and 48.

[0182] In the present application, the antigen binding protein may comprise an HCDR3, and the HCDR3 may comprise the amino acid sequence shown in SEQ ID NO:368: GKEX4X5X6YYAMDF (SEQ ID NO:368); wherein X4=H, I or N; X5=A or G; and X6=K or N. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0183] For example, the HCDR3 may comprise an amino acid sequence set forth in any one of SEQ ID NOs: 72 and 80-83.

[0184] In the present application, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, and the HCDR1, HCDR2 and HCDR3 may comprise the amino acid sequences set forth in SEQ ID NO:22, SEQ ID NO:367 and SEQ ID NO:368, respectively, in that order. Optionally, the HCDR1 of the antigen binding protein may comprise the amino acid sequence set forth in SEQ ID NO:22, the HCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:38 or 48, and the HCDR3 may comprise the amino acid sequence set forth in any one of SEQ ID NOs:72 and 80-83.

[0185] For example, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, and the combination of HCDR1, HCDR2 and HCDR3 may comprise any group selected from Table 7 below. [Table 7]

[0186] In the present application, the antigen binding protein may comprise a framework region H-FR1. The C-terminus of the H-FR1 is directly or indirectly connected to the N-terminus of the HCDR1. For example, the H-FR1 may comprise the amino acid sequence shown in SEQ ID NO:7. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0187] In the present application, the antigen binding protein may comprise an H-FR2, wherein the H-FR2 is between the HCDR1 and the HCDR2. For example, the H-FR2 may comprise the amino acid sequence shown in SEQ ID NO:27. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0188] In the present application, the antigen binding protein may comprise an H-FR3, said H-FR3 being between said HCDR2 and said HCDR3, for example, said H-FR3 may comprise the amino acid sequence shown in SEQ ID NO: 56. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0189] In the present application, the antigen binding protein may comprise an H-FR4, and the N-terminus of the H-FR4 may be linked to the C-terminus of the HCDR3. For example, the H-FR4 may comprise the amino acid sequence shown in SEQ ID NO:89. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0190] In the present application, the antigen binding protein may comprise a heavy chain variable region VH, and the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 196 and 206-211. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0191] In the present application, the antigen binding protein may comprise an Fc region, for example, the Fc region may comprise a modification to enhance ADCC effect.

[0192] In the present application, the antigen binding protein may comprise an Fc region, for example, the glycosylated side chain of the Fc region may be free of a fucose group, or the Fc region may be free of a glycosylated side chain of a fucose group.

[0193] The antigen binding protein of the present application may comprise a heavy chain constant region CH, and the antibody heavy chain constant region may comprise a human IgG constant region. Optionally, the human IgG constant region may comprise a human IgG1 constant region. The human IgG1 constant region may comprise natural and synthetic IgG1 constant regions or variants thereof. The mutations may comprise one or more of the following mutations: S239D and I332E. For example, the human IgG1 constant region of the fusion protein may comprise the amino acid sequence shown in SEQ ID NO:356 or 357.

[0194] In the present application, the antigen binding protein can comprise an antibody heavy chain. For example, the antibody heavy chain can comprise an amino acid sequence as set forth in any one of SEQ ID NOs:299-318.

[0195] In the present application, the antigen binding protein may comprise at least one CDR in an antibody light chain variable region VL, wherein the VL may comprise the amino acid sequence shown in SEQ ID NO:237.

[0196] In the present application, the antigen binding protein may comprise an LCDR1, and the LCDR1 may comprise the amino acid sequence shown in SEQ ID NO: 111. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0197] In the present application, the antigen binding protein may comprise an LCDR2, and the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO: 127. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0198] In the present application, the antigen binding protein may comprise an LCDR3, and the LCDR3 may comprise the amino acid sequence shown in SEQ ID NO: 142. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0199] In the present application, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, in which the LCDR1 may comprise the amino acid sequence shown in SEQ ID NO:111, the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO:127, and the LCDR3 may comprise the amino acid sequence shown in SEQ ID NO:142.

[0200] In the present application, the antigen binding protein may comprise a framework region L-FR1. The C-terminus of the L-FR1 is directly or indirectly connected to the N-terminus of the LCDR1. For example, the L-FR1 may comprise the amino acid sequence shown in SEQ ID NO:99. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0201] In the present application, the antigen binding protein may comprise an L-FR2, and the L-FR2 is between the LCDR1 and the LCDR2. For example, the L-FR2 may comprise the amino acid sequence shown in SEQ ID NO: 123. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0202] In the present application, the antigen binding protein may comprise an L-FR3, said L-FR3 being between said LCDR2 and said LCDR3, for example, said L-FR3 may comprise the amino acid sequence shown in SEQ ID NO: 136. For example, said sequence may be a sequence determined based on the Chothia definition rules.

[0203] In the present application, the antigen binding protein may comprise an L-FR4, and the N-terminus of the L-FR4 may be linked to the C-terminus of the LCDR3. For example, the L-FR4 may comprise the amino acid sequence shown in SEQ ID NO: 164. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0204] In the present application, the antigen binding protein may comprise a light chain variable region VL, and the VL may comprise the amino acid sequence shown in SEQ ID NO: 237. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0205] The antigen binding protein of the present application may comprise a light chain constant region CL, and the antibody light chain constant region may comprise a human Igκ constant region. For example, the CL region may comprise the amino acid sequence shown below: SEQ ID NO:358.

[0206] In the present application, the antigen binding protein can comprise an antibody light chain. For example, the antibody light chain can comprise the amino acid sequence shown in SEQ ID NO:344.

[0207] In the present application, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise the amino acid sequences set forth in SEQ ID NO:22, SEQ ID NO:367, SEQ ID NO:368, SEQ ID NO:111, SEQ ID NO:127 and SEQ ID NO:142, respectively, in order.

[0208] In some cases, the HCDR1 of the antigen binding protein may comprise the amino acid sequence set forth in SEQ ID NO:22, the HCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:38 or 48, and the HCDR3 may comprise the amino acid sequence set forth in any one of SEQ ID NOs:72, 80, 81, 82, and 83, the LCDR1 may comprise the amino acid sequence set forth in SEQ ID NO:111, the LCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 may comprise the amino acid sequence set forth in SEQ ID NO:142.

[0209] For example, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the combination of HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise any group selected from Table 8 below. [Table 8]

[0210] In the present application, the antigen binding protein may comprise an antibody heavy chain variable region (VH) and a light chain variable region (VL). For example, the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 196 and 206-211, and the VL may comprise an amino acid sequence as set forth in SEQ ID NO: 237. For example, the antigen binding protein may comprise a VH and a VL, and the combination of the VH and VL may comprise any group selected from Table 9 below. [Table 9]

[0211] In the present application, the antigen binding protein may comprise an antibody light chain and an antibody heavy chain, wherein the light chain may comprise the amino acid sequence shown in SEQ ID NO:344, and the heavy chain may comprise the amino acid sequence shown in any one of SEQ ID NOs:299-318. For example, the light and heavy chain combination of the antigen binding protein may comprise any group selected from Table 10 below. [Table 10]

[0212] In the present application, the isolated antigen-binding protein is capable of binding CCR8 of human origin.

[0213] In the present application, the isolated antigen binding protein can comprise at least one CDR in an antibody heavy chain variable region VH. The VH can comprise an amino acid sequence as set forth in SEQ ID NO: 331. For example, the VH can comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 167, 168, and 170-176.

[0214] In the present application, the antigen binding protein may comprise an HCDR1, and the HCDR1 may comprise the amino acid sequence shown in SEQ ID NO:363: X1FTFX5TX7 (SEQ ID NO:363); wherein X1=E or G; X5=N or S; X7=N or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the HCDR1 may comprise an amino acid sequence as shown in any one of SEQ ID NOs:15-18.

[0215] In the present application, the antigen binding protein may comprise an HCDR2, and the HCDR2 may comprise the amino acid sequence shown in SEQ ID NO:364: RX2KX4NNX7A (SEQ ID NO:364); wherein X2=S or T; X4=M or S; X7=F or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the HCDR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:37-39.

[0216] In the present application, the antigen binding protein can comprise an HCDR3, and the HCDR3 can comprise the amino acid sequence shown in SEQ ID NO:365: GKX3X4GNYYAMDX. 12 (SEQ ID NO:365); wherein X3=D or E; X4=N or Y; X 12 = F or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the HCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:65-67.

[0217] In the present application, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, in which the HCDR1 may comprise the amino acid sequence shown in SEQ ID NO:363, the HCDR2 may comprise the amino acid sequence shown in SEQ ID NO:364, and the HCDR3 may comprise the amino acid sequence shown in SEQ ID NO:365.

[0218] In the present application, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, in which the HCDR1 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 15-18, the HCDR2 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 37-39, and the HCDR3 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 65-67. For example, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, and the combination of HCDR1, HCDR2 and HCDR3 may be selected from any of the groups in the table below: [Table 11]

[0219] In the present application, the antigen binding protein may comprise a framework region H-FR1. The C-terminus of the H-FR1 is directly or indirectly connected to the N-terminus of the HCDR1. For example, the H-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs: 1-4. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0220] In the present application, the antigen binding protein may comprise an H-FR2, wherein the H-FR2 is between the HCDR1 and the HCDR2. For example, the H-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 26 and 27. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0221] In the present application, the antigen binding protein may comprise an H-FR3, said H-FR3 being between said HCDR2 and said HCDR3, for example, said H-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 49-52, for example, said sequence may be a sequence determined based on the Chothia definition rules.

[0222] In the present application, the antigen binding protein may comprise an H-FR4, and the N-terminus of the H-FR4 may be linked to the C-terminus of the HCDR3. For example, the H-FR4 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:84-86. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0223] In the present application, the antigen binding protein may comprise a heavy chain variable region VH, and the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 167, 168 and 170-176.

[0224] In the present application, the antigen binding protein may comprise an Fc region, for example, the Fc region may comprise a modification to enhance ADCC effect.

[0225] In the present application, the antigen binding protein may comprise an Fc region, for example, the glycosylated side chain of the Fc region may be free of a fucose group, or the Fc region may be free of a glycosylated side chain of a fucose group.

[0226] The antigen binding protein of the present application may comprise a heavy chain constant region CH, and the antibody heavy chain constant region may comprise a human IgG constant region. Optionally, the human IgG constant region may comprise a human IgG1 constant region. The human IgG1 constant region may comprise natural and artificial synthetic IgG1 constant regions or variants thereof. The mutations may comprise one or more of the following mutations: S239D and I332E. For example, the human IgG1 constant region of the fusion protein may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:356-357.

[0227] In the present application, the antigen binding protein can comprise an antibody heavy chain. For example, the antigen binding protein can comprise an amino acid sequence set forth in any one of SEQ ID NOs: 249, 250, 252, 253, 255, 256, 257, 258, and 261.

[0228] In the present application, the antigen binding protein may comprise at least one CDR in an antibody light chain variable region VL, wherein the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 212, 213, 215, 216, 218, 219, 221, 222, 231 and 235.

[0229] In the present application, the antigen binding protein may comprise an LCDR1, and the LCDR1 may comprise the amino acid sequence shown in SEQ ID NO:366: RSSKSLLX8SNGNTYLY (SEQ ID NO:366); wherein X8=H or Y. For example, the sequence may be a sequence determined based on the Chothia definition rules. For example, the LCDR1 may comprise an amino acid sequence set forth in any one of SEQ ID NOs:104-105.

[0230] In the present application, the antigen binding protein may comprise an LCDR2, and the LCDR2 may comprise the amino acid sequence shown in SEQ ID NO: 127. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0231] In the present application, the antigen binding protein may comprise an LCDR3, and the LCDR3 may comprise the amino acid sequence shown in SEQ ID NO: 141. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0232] In the present application, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, and the LCDR1, LCDR2 and LCDR3 may comprise the amino acid sequences shown in SEQ ID NO: 366, SEQ ID NO: 127 and SEQ ID NO: 141, respectively, in that order. Optionally, the LCDR1 of the antigen binding protein may comprise the amino acid sequence shown in any one of SEQ ID NO: 104 and SEQ ID NO: 105. For example, the LCDR1 of the antigen binding protein may comprise the amino acid sequence set forth in SEQ ID NO:104, the LCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 may comprise the amino acid sequence set forth in SEQ ID NO:141. For example, the LCDR1 of the antigen binding protein may comprise the amino acid sequence set forth in SEQ ID NO:105, the LCDR2 may comprise the amino acid sequence set forth in SEQ ID NO:127, and the LCDR3 may comprise the amino acid sequence set forth in SEQ ID NO:141.

[0233] In the present application, the antigen binding protein may comprise a framework region L-FR1. The C-terminus of the L-FR1 is directly or indirectly connected to the N-terminus of the LCDR1. For example, the L-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs:90-94 and 98-99. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0234] In the present application, the antigen binding protein may comprise an L-FR2, wherein the L-FR2 is between the LCDR1 and the LCDR2. For example, the L-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 118, 122, and 123. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0235] In the present application, the antigen binding protein may comprise an L-FR3, said L-FR3 being between said LCDR2 and said LCDR3, for example, said L-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 135-136, for example, said sequence may be a sequence determined based on the Chothia definition rules.

[0236] In the present application, the antigen binding protein may comprise an L-FR4, and the N-terminus of the L-FR4 may be linked to the C-terminus of the LCDR3. For example, the L-FR4 may comprise an amino acid sequence shown in any one of SEQ ID NOs: 154-157, 160, 161 and 164. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0237] In the present application, the antigen binding protein may comprise a light chain variable region VL, and the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 212, 213, 215, 216, 218, 219, 221, 222, 231, and 235. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0238] The antigen binding protein of the present application may comprise a light chain constant region CL, and the antibody light chain constant region may comprise a human Igκ constant region. For example, the CL region may comprise the amino acid sequence shown below: SEQ ID NO:358.

[0239] In the present application, the antigen binding protein can comprise an antibody light chain. For example, the antigen binding protein can comprise an amino acid sequence set forth in any one of SEQ ID NOs: 319, 320, 322, 323, 325, 326, 328, 329, 338, and 342.

[0240] In the present application, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise the amino acid sequences shown in SEQ ID NO:363, SEQ ID NO:364, SEQ ID NO:365, SEQ ID NO:366, SEQ ID NO:127 and SEQ ID NO:141, respectively. In some cases, the HCDR1 of the antigen binding protein may comprise an amino acid sequence set forth in any one of SEQ ID NOs: 15-18, the HCDR2 may comprise an amino acid sequence set forth in any one of SEQ ID NOs: 37-39, and the HCDR3 may comprise an amino acid sequence set forth in any one of SEQ ID NOs: 65-67, the LCDR1 may comprise an amino acid sequence set forth in any one of SEQ ID NOs: 104-105, the LCDR2 may comprise an amino acid sequence set forth in SEQ ID NO: 127, and the LCDR3 may comprise an amino acid sequence set forth in SEQ ID NO: 141.

[0241] For example, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the combination of HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise any group selected from Table 12 below. [Table 12]

[0242] In the present application, the antigen binding protein may comprise an antibody heavy chain variable region VH and light chain variable region VL. For example, the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 167, 168, and 170-176, and the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 212, 213, 215, 216, 218, 219, 221, 222, 231, and 235.

[0243] For example, the antigen binding protein may comprise a VH and a VL, and the combination of the VH and VL may comprise any group selected from Table 13 below. [Table 13]

[0244] In the present application, the antigen binding protein can comprise an antibody heavy chain and an antibody light chain. For example, the heavy chain can comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 249, 250, 252, 253, 255, 256, 257, 258, and 261, and the light chain can comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 319, 320, 322, 323, 325, 326, 328, 329, 338, and 342.

[0245] For example, the antigen binding protein may comprise a combination of light and heavy chains and may comprise any group selected from Table 14 below. [Table 14]

[0246] In the present application, the antigen binding protein may comprise at least one CDR in an antibody heavy chain variable region VH, and the VH may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205.

[0247] In the present application, the antigen binding protein may comprise an HCDR1. For example, the HCDR1 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 16, 19, 20, 23, 24, and 25. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0248] In the present application, the antigen binding protein may comprise an HCDR2. For example, the HCDR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 38 and 40-47. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0249] In the present application, the antigen binding protein may comprise an HCDR3. For example, the HCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 66, 69, 70, 71, 74-79. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0250] In the present application, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, in which the HCDR1 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 16, 19, 20, 23, 24 and 25, the HCDR2 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 38 and 40-47, and the HCDR3 may comprise an amino acid sequence as shown in any one of SEQ ID NOs: 66, 69, 70, 71, 74-79.

[0251] For example, the antigen binding protein may comprise HCDR1, HCDR2 and HCDR3, and the combination of HCDR1, HCDR2 and HCDR3 may be selected from any of the groups in Table 15 below. [Table 15]

[0252] In the present application, the antigen binding protein may comprise a framework region H-FR1. The C-terminus of the H-FR1 is directly or indirectly connected to the N-terminus of the HCDR1. For example, the H-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs:5, 6 and 9-14. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0253] In the present application, the antigen binding protein may comprise an H-FR2, wherein the H-FR2 is between the HCDR1 and the HCDR2. For example, the H-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 26, 28, 29, and 32-36. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0254] In the present application, the antigen binding protein may comprise an H-FR3, wherein the H-FR3 is between the HCDR2 and the HCDR3, for example, the H-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 50, 53-55, and 58-64. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0255] In the present application, the antigen binding protein may comprise an H-FR4, and the N-terminus of the H-FR4 may be linked to the C-terminus of the HCDR3. For example, the H-FR4 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 84-85 and 87-89. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0256] In the present application, the antigen binding protein may comprise a heavy chain variable region VH, and the VH region may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205.

[0257] In the present application, the antigen binding protein may comprise an Fc region, for example, the Fc region may comprise a modification to enhance ADCC effect.

[0258] In the present application, the antigen binding protein may comprise an Fc region, for example, the glycosylated side chain of the Fc region may be free of a fucose group, or the Fc region may be free of a glycosylated side chain of a fucose group.

[0259] The antigen binding protein of the present application may comprise a heavy chain constant region CH, and the antibody heavy chain constant region may comprise a human IgG constant region. Optionally, the human IgG constant region may comprise a human IgG1 constant region. The human IgG1 constant region may comprise natural and artificial synthetic IgG1 constant regions or variants thereof. The mutations may comprise one or more of the following mutations: S239D and I332E. For example, the human IgG1 constant region of the fusion protein may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:356-357.

[0260] In the present application, the antigen binding protein can comprise an antibody heavy chain. For example, the antigen binding protein can comprise an amino acid sequence set forth in any one of SEQ ID NOs: 263, 264, 265, and 285-298.

[0261] In the present application, the antigen binding protein may comprise at least one CDR in an antibody light chain variable region VL, and the VL may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 224-226, 238-241 and 245-248.

[0262] In the present application, the antigen binding protein may comprise an LCDR1. For example, the LCDR1 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 104, 105, 108-110 and 113-117. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0263] In the present application, the antigen binding protein may comprise an LCDR2. For example, the LCDR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs:127-134. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0264] In the present application, the antigen binding protein may comprise an LCDR3. For example, the LCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 141, 143-149 and 153. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0265] In the present application, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, in which the LCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 104, 105, 108-110 and 113-117, the LCDR2 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 127-134, and the LCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 141, 143-149 and 153.

[0266] For example, the antigen binding protein may comprise LCDR1, LCDR2 and LCDR3, and the combination of LCDR1, LCDR2 and LCDR3 may be selected from any of the groups in Table 16 below. [Table 16]

[0267] In the present application, the antigen binding protein may comprise a framework region L-FR1. The C-terminus of the L-FR1 is directly or indirectly connected to the N-terminus of the LCDR1. For example, the L-FR1 may comprise an amino acid sequence shown in any one of SEQ ID NOs:90, 92, 95-97 and 99-103. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0268] In the present application, the antigen binding protein may comprise an L-FR2, and the L-FR2 is between the LCDR1 and the LCDR2. For example, the L-FR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 118-121 and 124-126. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0269] In the present application, the antigen binding protein may comprise an L-FR3, said L-FR3 being between said LCDR2 and said LCDR3, for example, said L-FR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 135-140, for example, said sequence may be a sequence determined based on the Chothia definition rules.

[0270] In the present application, the antigen binding protein may comprise an L-FR4, and the N-terminus of the L-FR4 may be linked to the C-terminus of the LCDR3. For example, the L-FR4 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 156, 157, 159 and 162-166. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0271] In the present application, the antigen binding protein may comprise a light chain variable region VL. For example, the VL region may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 224-226, 238-241 and 245-248. For example, the sequence may be a sequence determined based on the Chothia definition rules.

[0272] The antigen binding protein of the present application may comprise a light chain constant region CL, and the antibody light chain constant region may comprise a human Igκ constant region. For example, the CL region may comprise the amino acid sequence shown below: SEQ ID NO:358.

[0273] In the present application, the antigen binding protein can comprise an antibody light chain. For example, the antigen binding protein can comprise an amino acid sequence set forth in any one of SEQ ID NOs: 331-333, 345-348, and 352-355.

[0274] In the present application, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3. In some cases, the HCDR1 of the antigen binding protein may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 16, 19, 20, 23, 24, and 25; the HCDR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 38 and 40-47; the HCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 66, 69, 70, 71, and 74-79; the LCDR1 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 104, 105, 108-110, and 113-117; the LCDR2 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 127-134; and the LCDR3 may comprise an amino acid sequence as set forth in any one of SEQ ID NOs: 141, 143-149, and 153. For example, the antigen binding protein may comprise HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3, and the combination of HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 may comprise any group selected from Table 17 below. [Table 17]

[0275] In the present application, the antigen binding protein may comprise an antibody light chain variable region VL and an antibody heavy chain variable region VH, wherein the VH comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205, and the VL comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 224-226, 238-241 and 245-248.

[0276] In the present application, the antigen binding protein may comprise an antibody light chain variable region VL and an antibody heavy chain variable region VH, wherein the VH comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205, and the VL comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 224-226, 238-241 and 245-248. For example, the VL and VH combination of the antigen binding protein may comprise any group selected from Table 18 below. [Table 18]

[0277] In the present application, the antigen binding protein may include an antibody light chain and an antibody heavy chain, in which the antibody light chain may include an amino acid sequence as set forth in any one of SEQ ID NOs: 331-333, 345-348, and 352-355, and the antibody heavy chain may include an amino acid sequence as set forth in any one of SEQ ID NOs: 263, 264, 265, and 285-298. For example, the light and heavy chain combination of the antigen binding protein may comprise any group selected from Table 19 below. [Table 19]

[0278] The proteins, polypeptides, and / or amino acid sequences of the present application should be understood to include at least mutants or homologs having the same or similar functions as the proteins or polypeptides.

[0279] In the present application, a variant may be a protein or polypeptide having a substitution, deletion, or addition of one or more amino acids to the amino acid sequence of said protein and / or said polypeptide (e.g., an antigen binding protein described herein). For example, said functional variant may include a protein or polypeptide having an amino acid change due to at least one, such as 1-30, 1-20, or 1-10, also such as 1, 2, 3, 4 or 5 amino acid substitution, deletion, and / or insertion. A functional variant may substantially retain the biological properties of the protein or polypeptide prior to modification, such as substitution, deletion, or addition. For example, a functional variant may retain at least 60%, 70%, 80%, 90%, or 100% of the biological activity (e.g., antigen binding ability) of the protein or polypeptide prior to modification.

[0280] In the present application, a portion of each heavy or light chain amino acid sequence of the antigen-binding protein is homologous to a corresponding amino acid sequence in an antibody from a particular species or belongs to a particular class. For example, the variable and constant regions of the light and heavy chains are both derived from the variable and constant regions of an antibody of an animal species such as human. In the present application, the homology may be a protein or polypeptide having at least about 85% (e.g., at least about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or more) sequence homology with the amino acid sequence of the protein and / or polypeptide (e.g., an antibody or fragment thereof that specifically binds to CCR8 protein).

[0281] In this application, homology generally means the homology, similarity, or relatedness between two or more sequences. "Percent sequence identity" can be calculated in the following manner: two sequences to be compared are compared in a comparison window, and the number of positions in the two sequences where the same nucleic acid base (e.g., A, T, C, G) or the same amino acid residue (e.g., Ala, Pro, Ser, Thr, Gly, Val, Leu, Ile, Phe, Tyr, Trp, Lys, Arg, His, Asp, Glu, Asn, Gln, Cys, Met) is present is determined to obtain the number of matching positions, and the number of matching positions is divided by the total number of positions in the comparison window (i.e., the window size), and the result is multiplied by 100 to generate a percent sequence identity. Comparison to determine percent sequence identity can be performed in various ways known in the art, for example, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. Those skilled in the art can determine appropriate parameters for comparing sequences, including any algorithms necessary to achieve maximum comparison within the full length sequence range or within the target sequence region being compared. The homology can also be measured by FASTA and BLAST. A description of the FASTA algorithm can be found in W.R. Pearson and D.J. Lipman, "Improved Tools for Biological Sequence Comparison," Proc. Natl. Acad. Sci., 85:2444-2448, 1988; D.J. Lipman and W.R. Pearson, "Fast and Sensitive Protein Similarity Searching," Science, 227:1435-144, 1989. A description of the BLAST algorithm can be found in S. Altschul, W. Gish, W. Miller, E.W. Myers, D. Lipman, "Basic Local Alignment Search Tool," Journal of Molecular Biology, 215:403-410, 1990.

[0282] Detection Method The physical / chemical properties and / or biological activities of the CCR8 antigen binding proteins described herein can be identified, screened or characterized by various assays known in the art.

[0283] In one embodiment, the antigen binding activity of the CCR8 antigen binding protein of the present application can be tested by known methods such as, for example, enzyme-linked immunosorbent assay (ELISA), immunoblocking (e.g., protein blocking), flow cytometry (e.g., FACS), immunohistochemistry, immunofluorescence, etc.

[0284] In the present application, the isolated antigen binding protein is at least 2×10 -8 The primate CCR8 antigen-binding protein can bind to CCR8 from a primate with an EC50 value of M or lower. The binding affinity of the primate CCR8 antigen-binding protein to CCR8 can be determined by any method known in the art. In some cases, the binding affinity can be determined by in-chip multiplex detection. In some cases, the binding affinity and EC50 value of the CCR8 antigen-binding protein to CCR8 can be determined by flow cytometry (FACS).

[0285] In the present application, the isolated antigen-binding protein is detected using, for example, a FACS analyzer.

[0286] In another case, the binding activity of the CCR8 antigen-binding protein of the present application to CCR8 can be detected using flow cytometry or enzyme immunoassay. For example, in a FACS test, the CCR8 antigen-binding protein is incubated at 2×10 60 min using host cells (e.g., CHO-K1 cells) stably expressing human CCR8. -8 M or lower EC50 value. For example, the EC50 value is about 1×10 -8 M or lower, approximately 9 x 10 -9 M or lower, approximately 8 x 10 -9 M or lower, approximately 7 x 10 -9 M or lower, approximately 6 x 10 -9 M or lower, approximately 5 x 10 -9 M or lower, approximately 4 x 10 -9 M or lower, approximately 3 x 10 -9 M or lower, approximately 2 x 10 -9M or lower, approximately 1 x 10 -9 It can bind to human CCR8 at M or lower.

[0287] In another case, the antigen epitope competitive binding of the CCR8 antigen binding protein is determined by flow cytometry (FACS).

[0288] In another case, differential expression of CCR8 on human tumor-infiltrating lymphocyte-derived Tregs (TIL-Tregs) and normal human PBMC-derived Tregs is measured by flow cytometry (FACS).

[0289] Nucleic Acid Molecules, Vectors and Cells In one aspect, the present application provides one or more nucleic acid molecules capable of encoding the isolated antigen binding proteins and / or multispecific antibodies described herein. The nucleic acid molecules described herein may be isolated. For example, they may be generated or synthesized by: (i) in vitro amplified, e.g., by polymerase chain reaction (PCR) amplification; (ii) cloning recombination; (iii) purified, e.g., isolated by enzymatic cutting and gel electrophoretic sorting; or (iv) synthetic, e.g., chemically synthesized. In certain embodiments, the isolated nucleic acid is a nucleic acid molecule prepared by recombinant DNA techniques.

[0290] In one aspect, the present application provides a vector that can include the nucleic acid molecule described herein. In addition, the vector can include other genes, such as marker genes, that allow the vector to be selected in a suitable host cell and under suitable conditions. In addition, the vector can include expression control elements that allow the coding region to be correctly expressed in a suitable host. Such control elements are well known to those skilled in the art and can include, for example, promoters, ribosome binding sites, enhancers, and other control elements that regulate gene transcription or mRNA translation. The vector can include, for example, a plasmid, a mucilage particle, a virus, a phage, or other vectors commonly used, for example, in genetic engineering. For example, the vector is an expression vector.

[0291] In one aspect, the present application provides a cell that can include a nucleic acid molecule described herein or a vector described herein. In some embodiments, each or each host cell can include one or more of the nucleic acid molecules or vectors described herein. In certain embodiments, each or each host cell can include a plurality (e.g., two or more) or a plurality (e.g., two or more) of the nucleic acid molecules or vectors described herein. For example, the vectors described herein can be introduced into a host cell, such as a eukaryotic cell, such as a cell derived from a plant, a fungus, or a yeast cell. The vectors described herein can be introduced into a host cell by methods known in the art, such as electroporation, lipofectine transfection, lipofectamin transfection, etc.

[0292] Chimeric Antigen Receptor In one aspect, the present application provides a chimeric antigen receptor (CAR) that can include the nucleic acid molecule described herein or the antigen-binding fragment described herein. In one embodiment, the chimeric antigen receptor can include an extracellular domain capable of binding an antigen (extracellular binding domain), a hinge domain, a transmembrane domain, and a polypeptide that transmits a cytoplasmic signal to the domain (i.e., an intracellular signal domain). The hinge domain can be considered as a part to provide flexibility to the extracellular antigen-binding region. The intracellular signal domain means that it generates a signal that can promote immune effector function of the cell of the CAR (e.g., a CAR-T cell) through a protein that transmits information intracellularly by generating a second messenger through a determined signal transduction pathway to regulate cell activity, or a protein that functions as an effector in response to such a messenger. The intracellular signal domain can include a signal transduction domain and can also include a costimulatory intracellular domain derived from a costimulatory molecule. For example, the costimulatory molecule can be selected from 4-1BB (i.e., CD137), CD27, ICOS, and / or CD28. In one aspect, the present application provides a genetically modified cell that can include the chimeric antigen receptor. In some embodiments, the genetically modified cell can comprise a eukaryotic cell. In some embodiments, the genetically modified cell can comprise an isolated human cell. In some embodiments, the genetically modified cell can comprise an immune cell, such as a T cell, or a NK cell.

[0293] Antibody Drug Conjugates In one aspect, the present application provides an antibody-drug conjugate that can include a cytotoxic agent and an antigen-binding fragment described herein. An antibody-drug conjugate generally means that an antibody and a small molecule cytotoxic agent are linked together using a specific linker, and its main components can include an antibody, a linker, and a small molecule cytotoxic agent. The targeting of the antibody-drug conjugate can come from the antibody portion, and most of the toxicity can come from the small molecule drug toxicant portion, and the antibody portion can also have its own toxicity (ADCC and CDC).

[0294] Pharmaceutical Compositions In one aspect, the present application provides a pharmaceutical composition that can include the isolated antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, and / or the antibody drug conjugate described herein, and optionally a pharma- ceutically acceptable vector. A pharma-ceutically acceptable vector is non-toxic to a recipient at the doses and concentrations used, and can include buffers, antioxidants, preservatives, low molecular weight (less than about 10 residues) polypeptides, proteins, hydrophilic polymers, amino acids, carbohydrates, salt-forming counterions, metal complexes, and / or non-ionic surfactants. The pharmaceutical compositions herein can also contain one or more active compounds that typically have complementary activities without adversely affecting each other. The type and effective amount of such drugs will depend, for example, on the amount and type of antagonist present in the formulation, and on the clinical parameters of the subject.

[0295] The pharmaceutical compositions described herein may comprise a prophylactically and / or therapeutically effective amount of the antigen binding protein, multispecific antibody. A prophylactically and / or therapeutically effective amount is the amount necessary to prevent and / or treat (at least partially treat) a disease or disorder, and / or any complications thereof, in a subject having or at risk of developing the disease or disorder.

[0296] The administration route of the pharmaceutical composition according to the present invention is preferably parenteral administration, injection administration or oral administration. Injection administration preferably includes routes such as intravenous injection, intramuscular injection, peritoneal injection, intradermal injection or subcutaneous injection. The pharmaceutical composition may be in various dosage forms conventional in the art, preferably in solid, semisolid or liquid form, i.e., aqueous, nonaqueous or suspension, more preferably, tablet, capsule, granule, injection or infusion, etc. More preferably, it is administered intravascularly, subcutaneously, intraperitoneally or intramuscularly. Preferably, the pharmaceutical composition may be administered as an aerosol or coarse spray, i.e., intranasally, or may be administered intrathecally, intramedullary or intraventricularly. More preferably, the pharmaceutical composition may be administered transdermally, transdermally, topically, enterally, intravaginally, sublingually or rectally. The pharmaceutical composition of the present invention may be prepared in various dosage forms as required, and a doctor may determine a beneficial dosage for a patient based on factors such as the type, age, weight and general disease state of the patient, and the method of administration. The method of administration may be, for example, an injection or other treatment method.

[0297] The dosage level of the pharmaceutical composition according to the present invention can be adjusted according to the amount of the composition to achieve the desired diagnostic or therapeutic result. The administration scheme can be a single injection or multiple injections, or can be adjusted. The selected dosage level and scheme can be reasonably adjusted depending on various factors, including the activity and stability (i.e., half-life) of the pharmaceutical composition, the formulation, the route of administration, the combination with other drugs or treatments, the disease or disorder to be detected and / or treated, and the health condition and previous medical history of the subject to be treated, etc.

[0298] kit In one aspect, the present application provides kits that can include the antigen binding proteins, chimeric antigen receptors, genetically modified cells, antibody drug conjugates, and / or pharmaceutical compositions described herein, which can include the antigen binding proteins, chimeric antigen receptors, genetically modified cells, and / or antibody drug conjugates described herein in a single common container, or optionally in combination with one or more therapeutic agents, optionally formulated together in a pharmaceutical composition.

[0299] In some cases, the kit may include a device for administering the antigen binding protein, chimeric antigen receptor, genetically modified cell, antibody drug conjugate, or pharmaceutical composition of the present application, e.g., the device depends on the method of application of the contents. In some cases, the kit may include a package insert page that includes information regarding the antigen binding protein, pharmaceutical composition, and dosage form in the kit. In general, such information assists patients and physicians in effectively and safely using the encapsulated antigen binding protein, pharmaceutical composition, and dosage form. The containers used in such kits may typically include at least one vial, test tube, flask, bottle, syringe, or other suitable container into which one or more of the detection and / or treatment compositions may be placed, preferably appropriately aliquoted. If a second therapeutic agent is also provided, the kit may include a second, different container into which the second detection and / or treatment composition may be placed. Alternatively, multiple compounds may be prepared as a single pharmaceutical composition and packaged in a single container device, such as a vial, flask, syringe, vial, or other suitable single container.

[0300] Dosing device In one aspect, the present application provides an administration device, such as a plastic or vial, e.g., a hollow pin or a syringe cylinder, that can be used to administer the antigen binding protein or pharmaceutical composition thereof described herein. The device can introduce the substance into the patient's body via a parenteral route (e.g., intramuscular, subcutaneous, or intravenous). For example, the injection device can be a syringe (e.g., a syringe pre-filled with the antigen binding protein or pharmaceutical composition thereof) that can include a cylinder for containing the fluid to be injected (e.g., the antigen binding protein or pharmaceutical composition thereof) and a needle (that can be used to puncture the skin and / or blood vessel). The method of administration can be varied. The route of administration can include oral administration, intramuscular injection, subcutaneous injection, rectal administration, etc.

[0301] Manufacturing method In one aspect, the present application provides a method for producing said antigen-binding protein. The method can include culturing a host cell described herein under conditions that allow expression of the antigen-binding protein. For example, this can be done by using a suitable medium, a suitable temperature, and a suitable culturing time, and the like, and these methods are known to those skilled in the art.

[0302] Any method suitable for producing monoclonal antibodies can be used to produce the antigen-binding proteins of the present application. For example, a linked or naturally occurring CCR8 protein or fragment thereof can be used to immunize an animal. Any suitable immunization method can be used, including adjuvants, immunostimulants, and repeated booster immunizations, and one or more routes can be used.

[0303] Any suitable form of CCR8 can be used as an immunogen (antigen) to generate non-human antibodies specific to CCR8 and to screen the biological activity of the antibodies. The exciting immunogen can be full-length mature human CCR8, including naturally occurring homologous dimers, or peptides containing single / multiple epitopes. The immunogen can be used alone or in combination with one or more immunogenicity enhancing agents known in the art.

[0304] The humanized antibody can be selected from any type of immunoglobulin, including IgM, IgD, IgG, IgA, IgE. In the present application, the antibody is an IgG antibody, and IgG1 or IgG4 subtypes are used. Optimization of the required constant domain sequence can be achieved by screening the antibody using the biological assays described in the Examples below to generate the required biological activity. Similarly, any light chain can be used in the compounds and methods herein. In particular, kappa, lambda chains or variants thereof can be used in the compounds and methods herein.

[0305] The sequence of the DNA molecule of the antigen binding protein of the present application or a fragment thereof can be obtained using conventional techniques such as PCR amplification or genomic library screening. The coding sequences of the light and heavy chains can also be fused to form a single chain antibody.

[0306] Once the relevant sequence is obtained, recombinant methods can be used to obtain large quantities of the relevant sequence. This is usually done by cloning into a vector, transferring into a cell, and isolating from the host cell after propagation in a conventional manner to obtain the relevant sequence. In addition, methods of artificially synthesizing the relevant sequence, especially if the fragment is short in length, can also be used. Generally, multiple small segments are first synthesized and then ligated to obtain a long segment of the sequence. The nucleic acid molecule can then be introduced into a variety of existing DNA molecules (or vectors, etc.) and cells known in the art.

[0307] The present application also relates to vectors comprising the above-mentioned suitable nucleic acid molecules and suitable promoters or control sequences. These vectors can be used to transform suitable host cells so that the proteins can be expressed. The host cells can be prokaryotic cells, such as bacterial cells, lower eukaryotic cells, such as yeast cells, or higher eukaryotic cells, such as mammalian cells. For example, animal cells include, but are not limited to, CHO-S, CHO-K1, HEK-293 cells.

[0308] The step of transforming a host cell with the recombinant DNA described herein can be carried out using techniques well known in the art. The resulting transformants can be cultured in a conventional manner to express the polypeptide encoded by the nucleic acid molecule of the present application. Depending on the host cell used, they are cultured in a conventional medium under appropriate conditions. Typically, the transformed host cell is cultured under conditions suitable for the expression of the antigen-binding protein of the present application. The antigen-binding protein of the present application is then purified using conventional isolation and purification means well known to those skilled in the art, such as protein A-Sepharose, hydroxyapatite chromatography, gel electrophoresis, dialysis, ion exchange chromatography, hydrophobic chromatography, molecular sieve chromatography or affinity chromatography.

[0309] The monoclonal antibodies obtained can be identified by conventional means, for example, the binding specificity of the monoclonal antibodies can be determined by immunoprecipitation or by in vitro binding assays such as flow cytometer technology (FACS) or enzyme-linked immunosorbent assay (ELISA).

[0310] Methods and Uses In one aspect, the present application provides the use of said antigen binding protein, said nucleic acid molecule, said vector, said cell, said chimeric antigen receptor, said genetically modified cell, said antibody drug conjugate and / or said pharmaceutical composition in the manufacture of a medicament, which can be used for treating cancer, inhibiting tumor growth, and / or inhibiting tumor cell proliferation.

[0311] In one aspect, the present application provides a method of preventing, alleviating or treating a CCR8 mediated disease or disorder, the method comprising administering to a subject in need thereof an antigen binding protein, a nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate, and / or the pharmaceutical composition.

[0312] In one aspect, the present application provides the antigen binding protein, the nucleic acid molecule, the vector, the cell, the chimeric antigen receptor, the genetically modified cell, the antibody drug conjugate and / or the pharmaceutical composition for preventing, alleviating or treating a CCR8 mediated disease or disorder.

[0313] In some embodiments, the tumor or cancer is a tumor or cancer with aberrant CCR8 expression, for example, the tumor can include breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer, and / or colon cancer. The antigen binding protein and / or pharmaceutical composition can be used to inhibit tumor growth. The aberrant CCR8 expression can be aberrant CCR8 expression on regulatory T cells (Treg). The aberrant CCR8 expression can be aberrant CCR8 expression on tumor-infiltrating regulatory T cells (Treg). For example, the pharmaceutical composition of the present application can inhibit or delay disease progression or progression, reduce tumor size (even substantially remove the tumor), and / or alleviate and / or stabilize the disease state.

[0314] In the present application, the method can be used in combination with one or more other anti-tumor therapies. For example, the other anti-tumor therapies include immunotherapies. For example, the other anti-tumor therapies include immune test point inhibitors. For example, the other anti-tumor therapies include PD-1 antibodies and / or PD-L1 antibodies. For example, the PD-1 antibodies include: and / or RMP1-14. For example, the PD-L1 antibodies include:

[0315] In one aspect, the present application provides a method of inhibiting calcium ion influx by CCL1, the method comprising administering the isolated antigen binding protein and / or pharmaceutical composition. For example, the method may be a method away from the body or an in vitro method. For example, the method may be a method for non-diagnostic and / or therapeutic purposes.

[0316] In one aspect, the present application provides a method of inhibiting CCL1-induced cell migration, the method comprising administering the isolated antigen binding protein and / or pharmaceutical composition. For example, the method may be a method away from the body or an in vitro method. For example, the method may be a method for non-diagnostic and / or therapeutic purposes.

[0317] In one aspect, the present application provides the following embodiments: 1. An isolated antigen binding protein comprising an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence set forth in SEQ ID NO:363, said HCDR2 comprises the amino acid sequence set forth in SEQ ID NO:364, and said HCDR3 comprises the amino acid sequence set forth in SEQ ID NO:365. 2. The isolated antigen binding protein according to embodiment 1, wherein the HCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 15-18, the HCDR2 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 37-39, and the HCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 65-67; ​​preferably, the HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from the group consisting of: (1) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 37, and HCDR3: SEQ ID NO: 65, (2) HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (3) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65, (4) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66, (5) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 67, (6) HCDR1: SEQ ID NO: 17, HCDR2: SEQ ID NO: 39, and HCDR3: SEQ ID NO: 65, and (7) HCDR1: SEQ ID NO: 18, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65. 3. The isolated antigen binding protein of any one of embodiments 1-2, comprising an antibody heavy chain variable region VH, and wherein the VH comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 167, 168 and 170-176. 4. The isolated antigen binding protein according to any one of embodiments 1-3, comprising an antibody light chain or a fragment thereof, the antibody light chain or a fragment thereof comprising LCDR1, LCDR2 and LCDR3, in which the LCDR1 comprises the amino acid sequence shown in SEQ ID NO:366, the LCDR2 comprises the amino acid sequence shown in SEQ ID NO:127 and the LCDR3 comprises the amino acid sequence shown in SEQ ID NO:141; preferably, the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from the group consisting of: (1) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141; and (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141. 5. The isolated antigen binding protein of any one of embodiments 1-4, comprising an antibody light chain variable region VL, and wherein the VL comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 212, 213, 215, 216, 218, 219, 221, 222, 231, and 235. 6. The isolated antigen binding protein of any one of embodiments 1-5, comprising an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any one of the following groups: (1) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 37, and HCDR3: SEQ ID NO: 65; (2) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (3) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 17, HCDR2: SEQ ID NO: 39, and HCDR3: SEQ ID NO: 65; (4) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (5) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 18, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; (6) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 15, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 65; and (7) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 67. 7. The isolated antigen binding protein of any one of embodiments 1-6, comprising an antibody heavy chain variable region VH and an antibody light chain variable region VL, wherein the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 212 and VH: SEQ ID NO: 167; (2) VL: SEQ ID NO: 213 and VH: SEQ ID NO: 168; (3) VL: SEQ ID NO: 215 and VH: SEQ ID NO: 170; (4) VL: SEQ ID NO: 216 and VH: SEQ ID NO: 171; (5) VL: SEQ ID NO: 218 and VH: SEQ ID NO: 173; (6) VL: SEQ ID NO: 219 and VH: SEQ ID NO: 174; (7) VL: SEQ ID NO: 221 and VH: SEQ ID NO: 175; (8) VL: SEQ ID NO: 222 and VH: SEQ ID NO: 176; (9) VL: SEQ ID NO: 231, and VH: SEQ ID NO: 172; and (10) VL: SEQ ID NO: 235, and VH: SEQ ID NO: 172. 8. An isolated antigen binding protein comprising an antibody heavy chain or a fragment thereof, said antibody heavy chain or a fragment thereof comprising HCDR1, HCDR2 and HCDR3, wherein said HCDR1 comprises the amino acid sequence as set forth in any one of SEQ ID NOs: 16, 19, 20, 23, 24 and 25, said HCDR2 comprises the amino acid sequence as set forth in any one of SEQ ID NOs: 38 and 40-47, and said HCDR3 comprises the amino acid sequence as set forth in any one of SEQ ID NOs: 66, 69, 70, 71 and 74-79; preferably, said HCDR1, HCDR2 and HCDR3 comprise an amino acid sequence selected from the group consisting of: (1) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 69; (2) HCDR1: SEQ ID NO: 20, HCDR2: SEQ ID NO: 41, and HCDR3: SEQ ID NO: 70; (3) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 71; (4) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 74; (5) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 44, and HCDR3: SEQ ID NO: 76; (6) HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 45, and HCDR3: SEQ ID NO: 77; (7) HCDR1: SEQ ID NO: 23, HCDR2: SEQ ID NO: 43, and HCDR3: SEQ ID NO: 75; (8) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 46, and HCDR3: SEQ ID NO: 78; (9) HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (10) HCDR1: SEQ ID NO: 25, HCDR2: SEQ ID NO: 47, and HCDR3: SEQ ID NO: 79; and (11) HCDR1: SEQ ID NO: 24, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 79. 9. The isolated antigen binding protein of embodiment 8, comprising an antibody heavy chain variable region VH, wherein the VH comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 178, 179, 180 and 198-205. 10. The isolated antigen binding protein according to any one of embodiments 8-9, comprising an antibody light chain or a fragment thereof, the antibody light chain or a fragment thereof comprising LCDR1, LCDR2 and LCDR3, wherein the LCDR1 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 104, 105, 108-110 and 113-117, the LCDR2 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 127-134, and the LCDR3 comprises an amino acid sequence as set forth in any one of SEQ ID NOs: 141, 143-149 and 153; preferably, the LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from the group consisting of: (1) LCDR1: SEQ ID NO: 108, LCDR2: SEQ ID NO: 128, and LCDR3: SEQ ID NO: 143, (2) LCDR1: SEQ ID NO: 109, LCDR2: SEQ ID NO: 129, and LCDR3: SEQ ID NO: 144, (3) LCDR1: SEQ ID NO: 110, LCDR2: SEQ ID NO: 130, and LCDR3: SEQ ID NO: 145, (4) LCDR1: SEQ ID NO: 113, LCDR2: SEQ ID NO: 131, and LCDR3: SEQ ID NO: 146, (5) LCDR1: SEQ ID NO: 115, LCDR2: SEQ ID NO: 133, and LCDR3: SEQ ID NO: 148, (6) LCDR1: SEQ ID NO: 116, LCDR2: SEQ ID NO: 134, and LCDR3: SEQ ID NO: 149, (7) LCDR1: SEQ ID NO: 114, LCDR2: SEQ ID NO: 132, and LCDR3: SEQ ID NO: 147, (8) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141, (9) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, and LCDR3: SEQ ID NO: 141, and (10) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, and LCDR3: SEQ ID NO: 153. 11. The isolated antigen binding protein of any one of embodiments 8-10, comprising an antibody light chain variable region VL, and wherein said VL comprises an amino acid sequence set forth in any one of SEQ ID NOs:224-226, 238-241 and 245-248. 12. The isolated antigen binding protein of any one of embodiments 8-11, comprising an antibody heavy chain or fragment thereof and an antibody light chain or fragment thereof, wherein the antibody heavy chain or fragment thereof comprises HCDR1, HCDR2 and HCDR3, and the antibody light chain or fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any one of the following groups: (1) LCDR1: SEQ ID NO: 108, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 143, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 69; (2) LCDR1: SEQ ID NO: 109, LCDR2: SEQ ID NO: 129, LCDR3: SEQ ID NO: 144, HCDR1: SEQ ID NO: 20, HCDR2: SEQ ID NO: 41, and HCDR3: SEQ ID NO: 70; (3) LCDR1: SEQ ID NO: 110, LCDR2: SEQ ID NO: 130, LCDR3: SEQ ID NO: 145, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 40, and HCDR3: SEQ ID NO: 71; (4) LCDR1: SEQ ID NO: 113, LCDR2: SEQ ID NO: 131, LCDR3: SEQ ID NO: 146, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 74; (5) LCDR1: SEQ ID NO: 115, LCDR2: SEQ ID NO: 133, LCDR3: SEQ ID NO: 148, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 44, and HCDR3: SEQ ID NO: 76; (6) LCDR1: SEQ ID NO: 116, LCDR2: SEQ ID NO: 134, LCDR3: SEQ ID NO: 149, HCDR1: SEQ ID NO: 19, HCDR2: SEQ ID NO: 45, and HCDR3: SEQ ID NO: 77; (7) LCDR1: SEQ ID NO: 114, LCDR2: SEQ ID NO: 132, LCDR3: SEQ ID NO: 147, HCDR1: SEQ ID NO: 23, HCDR2: SEQ ID NO: 43, and HCDR3: SEQ ID NO: 75; (8) LCDR1: SEQ ID NO: 105, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 46, and HCDR3: SEQ ID NO: 78; (9) LCDR1: SEQ ID NO: 104, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 141, HCDR1: SEQ ID NO: 16, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 66; (10) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 153, HCDR1: SEQ ID NO: 25, HCDR2: SEQ ID NO: 47, and HCDR3: SEQ ID NO: 79; and (11) LCDR1: SEQ ID NO: 117, LCDR2: SEQ ID NO: 128, LCDR3: SEQ ID NO: 153, HCDR1: SEQ ID NO: 24, HCDR2: SEQ ID NO: 42, and HCDR3: SEQ ID NO: 79. 13. The isolated antigen binding protein of any one of embodiments 8-12, comprising an antibody heavy chain variable region VH and an antibody light chain variable region VL, wherein the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 224 and VH: SEQ ID NO: 178; (2) VL: SEQ ID NO: 225 and VH: SEQ ID NO: 179; (3) VL: SEQ ID NO: 226 and VH: SEQ ID NO: 180; (4) VL: SEQ ID NO: 238 and VH: SEQ ID NO: 198; (5) VL: SEQ ID NO: 240 and VH: SEQ ID NO: 200; (6) VL: SEQ ID NO: 241 and VH: SEQ ID NO: 201; (7) VL: SEQ ID NO: 239 and VH: SEQ ID NO: 199; (8) VL: SEQ ID NO: 245 and VH: SEQ ID NO: 202; (9) VL: SEQ ID NO: 246 and VH: SEQ ID NO: 203; (10) VL: SEQ ID NO: 248, and VH: SEQ ID NO: 205; and (11) VL: SEQ ID NO: 247, and VH: SEQ ID NO: 204. 14. The isolated antigen binding protein of any one of embodiments 1-13, comprising a full length antibody, a Fab, a Fab', a F(ab')2, an Fv, preferably a scFv, a di-scFv, a bispecific antibody, a multispecific antibody, a heavy chain antibody and / or a single domain antibody, or a monoclonal and / or polyclonal antibody produced by said antibody. 15. The isolated antigen binding protein of embodiment 14, wherein the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a humanized antibody, and a fully human antibody. 16. One or more isolated nucleic acid molecules encoding the isolated antigen binding protein of any one of embodiments 1-15. 17. A vector comprising the nucleic acid molecule described in embodiment 16. 18. A cell comprising a nucleic acid molecule according to embodiment 16 or a vector according to embodiment 17. 19. A method for producing an isolated antigen binding protein according to any one of embodiments 1-15, the method comprising culturing a cell according to embodiment 18 under conditions that allow expression of the isolated antigen binding protein according to any one of embodiments 1-15. 20. A chimeric antigen receptor comprising an antigen-binding protein according to any one of embodiments 1-15. 21. A genetically modified cell comprising the chimeric antigen receptor according to embodiment 20; preferably a eukaryotic cell, preferably an isolated human cell; more preferably an immune cell such as a T cell or a NK cell. 22. An antibody drug conjugate comprising a cytotoxic agent and an antigen-binding protein according to any one of embodiments 1-15. 23. A pharmaceutical composition comprising the isolated antigen binding protein of any one of embodiments 1-15, the nucleic acid molecule of embodiment 16, the vector of embodiment 17, the cell of embodiment 18, the chimeric antigen receptor of embodiment 20, the genetically modified cell of embodiment 21, and / or the antibody drug conjugate of embodiment 22, and optionally a pharma- ceutical acceptable vector. 24. A kit comprising the isolated antigen binding protein of any one of embodiments 1-15, the nucleic acid molecule of embodiment 16, the vector of embodiment 17, the cell of embodiment 18, the chimeric antigen receptor of embodiment 20, the genetically modified cell of embodiment 21, the antibody drug conjugate of embodiment 22 and / or the pharmaceutical composition of embodiment 23; preferably the kit or administration device further comprising: (i) a device for administering said antigen binding protein, said nucleic acid molecule, said vector, said cell, said chimeric antigen receptor, said genetically modified cell, said antibody drug conjugate and / or said pharmaceutical composition; and / or (ii) instructions for use. 25. Use of the isolated antigen binding protein according to any one of the embodiments 1-15, the nucleic acid molecule according to the embodiment 16, the vector according to the embodiment 17, the cell according to the embodiment 18, the chimeric antigen receptor according to the embodiment 20, the genetically modified cell according to the embodiment 21, the antibody drug conjugate according to the embodiment 22 and / or the pharmaceutical composition according to the embodiment 23 in the manufacture of a drug, wherein the drug is used for preventing, alleviating and / or treating a CCR8-mediated disease or disorder. 26. The use according to embodiment 25, wherein the CCR8-mediated disease or disorder comprises a tumor, and the tumor is preferably breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and / or colon cancer. 27. A method for inhibiting calcium ion influx by CCL1, said method comprising administering an isolated antigen binding protein according to any one of embodiments 1-15 and / or a pharmaceutical composition according to embodiment 23; preferably an in vitro method or a method for non-diagnostic purposes. 28. A method for inhibiting CCL1-induced cell migration, the method comprising administering an isolated antigen binding protein according to any one of embodiments 1-15 and / or a pharmaceutical composition according to embodiment 23; preferably, the method is an in vitro method or a method for non-diagnostic purposes. 29. A method for preventing, alleviating and / or treating a CCR8-mediated disease or disorder, the method comprising administering to a subject in need thereof an isolated antigen binding protein according to any one of embodiments 1-15, a nucleic acid molecule according to embodiment 16, a vector according to embodiment 17, a cell according to embodiment 18, a chimeric antigen receptor according to embodiment 20, a genetically modified cell according to embodiment 21, an antibody drug conjugate according to embodiment 22 and / or a pharmaceutical composition according to embodiment 23. 30. The method according to embodiment 29, wherein the CCR8-mediated disease or disorder comprises a tumor, and the tumor is preferably breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer, or colon cancer. The following examples are intended to explain the fusion protein, production method, uses, etc. of the present application, but are not intended to limit the scope of the present invention.

[0318] Working Example Example 1 Immunization of Mice Balb / c mice and fully human H2L2 mice (HARBOUR BIOMED) were immunized multiple times with CCR8-HEK293 cells (prepared by standard methods). Booster immunizations were performed once every two weeks, for a total of five to six times. During the immunization period, serum titers of anti-human CCR8 antibodies were detected every two to three weeks by the FACS method. After multiple rounds of immunization, mice with optimal titers were selected according to the titer situation, and spleen cells were collected.

[0319] Example 2 Antibody Screening 2.1 Phage library screening 2.1.1 Construction of CCR8-immunized H2L2 and Balb / c mouse phage libraries Spleen cells were collected from the immunized mice, and splenic B cells were isolated from them. RNA was extracted using TRIZOl, and then RT-PCR was performed according to the product instructions (Thermofisher, Cat. No. 15596018) and the product instructions (Thermofisher, Cat. No. 11756500). Using cDNA as a template, VH (heavy chain variable region) and VL (light chain variable region) were amplified by the first PCR, and then overlap PCR was performed to prepare scFv fragments. TIFF0007610302000020.tif75153 TIFF0007610302000021.tif47153 TIFF0007610302000022.tif47153

[0320] The overlap PCR reaction system consisted of VH mixture, Vκ mixture, 5xQ5 reaction buffer, forward primer (10 μM), reverse primer (10 μM), 2.5 mM dNTPs, Q5 DNA polymerase and ddH2O, with a total volume of 25 μl.

[0321] The resulting ligation product was transformed into SS320 (Lucigen, Cat. No. 60512-1), and then a phage library was generated. Three rounds of biopanning (steps are as follows) were performed, and the phage library was screened by FACS using CHO-K1-hCCR8 cells overexpressing CCR8, and all the screened candidates (hits) were sequenced (steps are as follows) to generate specific molecules.

[0322] 2.1.2 Bio-Panning The phage library (1E13 phage granules) was depleted with CHO-K1 cells, then incubated with CHO-K1-hCCR8 cells at 4°C for 2 hours. Then washed with 1x PBS three times. After washing, the cell-phage mixture was added with pH 3.0 citrate buffer, incubated at room temperature for 10 minutes, and pH 9.0 Tris-HCl neutralization buffer was added, and then infected with 10 ml of SS320 cells at 37°C, the infection time was 45 minutes. Then 50 μl 2E12 / ml M13K07 helper phage (NEB, Cat. No. N0315S) was added to the infected cells, and finally 100 ml of 2xYT (containing 100 μg / ml Amp, 50 μg / ml Kan, 1 mM IPTG) was added, and incubated at 30°C overnight. 100 ml of overnight culture was centrifuged, the supernatant was collected, and 20% PEG8000 / 2.5M NaCl was added to the supernatant (1:5, volume ratio), followed by centrifugation at 8000 rpm for 20 min at 4°C. The phage precipitate obtained after centrifugation was resuspended in 1 mL 1x PBS. The resulting supernatant (phage granules) was transferred to a new tube to prepare for the second panning. The process of the second, third and fourth panning was the same as the procedure described above.

[0323] 2.1.3 Initial screening Colonies were selected into 96-well plates containing 2YT / AMP medium (Sangon Biotech, Cat. No. A507016-0250) and grown at 37°C for 3 hours. IPTG was added to a final concentration of 1 mM and induced overnight at 30°C. The supernatant was then centrifuged to precipitate, and the supernatant was collected and incubated with CHO-K1 cell line and Baf3 cell line overexpressing CCR8, respectively, and FACS test was performed. Clones with good binding activity were obtained by screening, variable region sequences were obtained by sequencing, and IgG recombinant antibodies were constructed and identified as PR004122, PR004125, PR004128, PR004131, PR004120, PR004121, PR004123, PR004124, PR004126, PR004127, PR004129, PR004130, PR004131, PR004120, PR004121, PR004123, PR004124, PR004126, PR004127, PR004129, PR004132, PR004133, PR004134, PR004135, PR004136, PR004137, PR004138, PR004139, PR004140, PR004141, PR004142, PR004143, PR004144, PR004145, PR004146, PR004147, PR004148, PR004149, PR004150, PR004151, PR004152, PR004153, PR004154, PR004155, PR00 PR004130, PR004264, PR004265, PR004275, PR005124, PR005125, PR005127, PR005128, PR005329, PR005330, PR005331, PR005332, PR005333, PR005335 and PR005336 have heavy chain constant regions derived from human IgG1 constant regions. At the same time, the IgG1 heavy chain constant regions of PR004122, PR004125, PR004128 and PR004131 were introduced with a "DE" (S239D, I332E) double mutant to enhance ADCC function, and the resulting antibody numbers were PR004249, PR004250, PR004251 and PR004252, respectively.

[0324] The initial antibody sequence numbers (SEQ ID NOs) and CDR sequences obtained by screening the phage library are shown below in Tables 20 and 21. The sequence numbers (SEQ ID NOs) and CDR sequences of antibodies with enhanced ADCC function obtained by heavy chain constant region "DE" mutations are shown below in Tables 22 and 23. [Table 20] [Table 21-1] [Table 21-2] [Table 22] [Table 23]

[0325] 2.2 Screening of single cell clones After mouse spleen cells and bone marrow cells isolated from high titer H2L2 mice were enriched via a plasma cell sorting kit (Miltenyi Biotec, cat 130-092-530, lot 5190121409), the Beacon platform (Berkeley Lights) was transported to the chip site by a microfluidic system, and single cells were separated into each cell of the chip by photoelectric positioning technology OEP. After incubating single B cells for a certain time (20 min), in-chip multiplex detection can be performed: not only can the detection of antigen-antibody specific binding based on magnetic beads be completed, but also the binding of antibodies and cell surface antigens can be detected by utilizing antigen-overexpressing cell lines. If the cells can secrete antigen-specific antibodies, fluorescent signals will be generated and identified by the instrument, and in this step, the detection test can be flexibly adjusted as needed. Single positive cells were extracted by OEP technology into 96-well plates containing cell lysis solution (Qiagen, cat. 1031586, lot. 163013365) and mineral oil (Sigma, cat. M 5904-500ML, lot. MKBZ6778V) for further sequencing, analysis and expression. The antibodies obtained were PR004970, PR004974 and PR005293.

[0326] The initial antibody sequence numbers (SEQ ID NOs) obtained by screening of single cell clones are shown in Table 24 below, and the antibody CDR sequences are shown in Table 25 below. [Table 24] [Table 25]

[0327] Example 3. Sequence optimization of monoclonal antibodies 3.1 Germline gene analysis and post-translational modification (PTM) optimization The heavy chain variable domain sequence of an antibody is derived from events such as gene rearrangement and somatic hypermutation of germline gene V, D, and J gene fragments of the heavy chain gene group on a chromosome. The light chain variable domain sequence is derived from events such as gene rearrangement and somatic hypermutation of germline gene V and J gene fragments of the light chain gene group. Gene rearrangement and somatic hypermutation are major factors that increase the diversity of antibodies. Antibodies derived from the same germline V gene fragment may also produce different sequences, but overall there is a high degree of similarity. Several algorithms, such as IMGT / DomainGapAlign (http: / / imgt.org / 3Dstructure-DB / cgi / DomainGapAlign.cgi) or NCBI / IgBLAST (https: / / www.ncbi.nlm.nih.gov / igblast / ), can be used to predict possible germline gene fragments when gene rearrangement occurs from the variable domain sequence of an antibody.

[0328] Chemical modifications may be introduced into the amino acid chain of a protein or polypeptide after translational synthesis in cells, and are called post-translational modifications (PTMs). For antibodies, some PTM sites are very conservative; for example, asparagine Asn, a conserved amino acid at position 297 (EU numbering) in the constant domain of human IgG1 antibodies, generally undergoes glycosylation modification to form a sugar chain, and the sugar chain structure is very important for antibody structure and related effector functions. However, if PTMs are present in the variable domain of an antibody, particularly in the antigen-binding region (e.g., CDR), the presence of these PTMs may have a significant effect on antigen binding and may also cause changes in the physicochemical properties of the antibody. For example, glycosylation, deamidation, isomerization, oxidation, etc., may all increase the instability or heterogeneity of the antibody molecule, thereby increasing the difficulty and risk of antibody development. Therefore, avoiding some potential PTMs is very important for the development of therapeutic antibodies. With the accumulation of experience, some PTMs have been found to be highly correlated with the composition of amino acid sequences, especially with the "pattern" of adjacent amino acid composition, and thus potential PTMs can be predicted from the primary amino acid sequence of a protein. For example, N-linked glycosylation sites are predicted from the sequence pattern NxS / T (first position is asparagine, second position is any amino acid other than non-proline, and third position is serine or threonine). The amino acid sequence pattern that causes PTMs may be derived from germline gene sequences, for example, the human germline gene fragment IGHV3-33 naturally has a glycosylation pattern NST in the FR3 region; it may also be derived from somatic hypermutation.

[0329] From the germline V gene fragments of the heavy chain variable domain (VH) and light chain variable domain (VL) of the PR004128 sequence (from monoclonal clone M3E3), we predicted that NG or NT may be potential PTM mutation sites.

[0330] Amino acid mutations can disrupt the amino acid sequence pattern of PTMs, thereby reducing or eliminating the formation of certain PTMs. There are different mutation design methods depending on the antibody sequence and PTM sequence pattern. One method is to replace the "hot spot" amino acid (e.g., N or S in an NS pattern) with a physicochemically similar amino acid (e.g., mutating N to Q). If the PTM sequence pattern is derived from somatic hypermutation and does not exist in the germline gene sequence, another method may be to replace the sequence pattern with the corresponding germline gene sequence. In practical operation, multiple mutation design methods may be adopted for the same PTM sequence pattern.

[0331] Amino acid mutations were performed at potential PTM sites of monoclonal antibody RP004128 to obtain new heavy chain variable region or light chain variable region derived mutants (referred to as PTM mutants), IgG1 recombinant sequences were constructed, and "DE" (S239D, I332E) double mutants were introduced into the heavy chain constant region to enhance ADCC function, and the antibody numbers of the obtained PTM mutants are PR004324, PR004325, PR004326, PR004327, PR004328 and PR004329, respectively. The sequence numbers of the PTM mutant antibodies of RP004128 are shown in Table 8 below, and the CDR sequences are shown in Table 9 below. [Table 26] [Table 27]

[0332] 3.2 Humanization of the variable region sequence of RP004128 In this example, the humanization of sequences is performed using the method of "CDR grafting", i.e., the CDRs of the VH of a mouse antibody are grafted into the framework regions of the VH of a human antibody, and the CDRs of the VL of a mouse antibody are grafted into the framework regions of the VL of a human antibody. The sequences of the framework regions of the VH or VL of a human antibody can be derived from human germline gene sequences, or antibody sequences after V(D)J rearrangement, or consensus sequences of a particular VH or VL gene family of human antibodies. In this example, framework region sequences provided by human germline gene sequences were used as humanization template sequences, i.e., a human germline V gene fragment provided the sequences of the framework regions FR1, FR2, FR3, and a human germline J gene fragment provided the sequence of the framework region FR4. Finally, humanized variable region (VH or VL) sequences were constructed in the following sequence format: (human)FR1-(mouse)CDR1-(human)FR2-(mouse)CDR2-(human)FR3-(mouse)CDR3-(human)FR4. In this example, the human germline V gene fragment IGHV3-73*01 or the human germline V gene fragment IGHV3-23*04 or the human germline V gene fragment IGHV3-15*07 was combined with the human germline J gene fragment IGHJ6*01 as a humanization template to provide a framework sequence. Then, amino acid mutations at one or more sites at positions 32, 73, 76, 78, 93, 94 or 102 (according to the Chothia numbering scheme) were introduced to obtain multiple different VH humanized variant sequences.

[0333] In this example, the human germline V gene fragment IGKV2-28*01 or the human germline V gene fragment IGKV2-30*02 and the human germline J gene fragment IGKJ2*01 were used as humanization templates to provide framework region sequences. Then, zero or multiple amino acid mutations were introduced at positions 2, 26, 30e, 31, 36, 46, or 96 (according to the Chothia numbering scheme) to obtain multiple different VL humanized variant sequences. In particular, Leu at position 96 (according to the Chothia numbering scheme) was mutated to Phe in some VL variants to study the effect of this site on target binding.

[0334] 3.3 Saturation mutagenesis study of position 96 of the RP004128 light chain 3.3.1 Saturation mutation We saturation mutated the 96th amino acid (Chothia designation) of the light chain of the RP004128 molecule and electrotransferred the PCR product into BL21 cells. We selected 192 monoclonals and sequenced them, and analyzed the sequences to find other mutants besides the wild type.

[0335] 3.3.2 Initial screening Wild-type and mutant colonies were selected into 96-well plates containing 2YT / AMP medium (Sangon Biotech, Cat. No. A507016-0250) and grown at 37°C for 3 hours. IPTG was added to a final concentration of 1 mM and induced overnight at 30°C. The supernatant was then centrifuged and precipitated, and the supernatant was collected for FACS testing. The antibody supernatants were co-incubated with monkey CCR8-overexpressing CHO-K1 cell lines and human CCR8-overexpressing CHO-K1 cell lines, respectively, and screened to obtain antibodies that could bind to CCR8 CHO-K1 cell lines.

[0336] 3.4 Production and characterization of recombinant antibody molecules derived from RP004128 The VH and VL variant sequences derived from RP004128 were paired and combined to construct an IgG recombinant antibody, and the "DE" (S239D, I332E) double mutant was introduced into the IgG1 heavy chain constant region to enhance the ADCC function. The purified recombinant antibody was obtained according to the method described in Example 4, and further verified in subsequent functional experiments. Table 28 lists the SEQ ID NOs of recombinant antibody molecules derived from the variable regions of RP004128, and Table 29 lists the CDR sequences of recombinant antibody molecules derived from the variable regions of RP004128. [Table 28] [Table 29-1] [Table 29-2]

[0337] Example 4 PR004666 Affinity Maturation 4.1 Construction of mutant phage library The four CDRs (HCDR2, HCDR3, LCDR1 and LCDR3) of the molecule PR004666 were randomly mutated to construct four phage libraries with a library capacity of approximately 10^10.

[0338] 4.2 Biopanning The phage library (1E13 phage granules) was depleted in CHO-K1 cells, then incubated with CHO-K1-hCCR8 cells at 4°C for 1 h. Then washed five times with 1x PBS. After washing, pH 3.0 citrate buffer was added to the cell-phage mixture and incubated at room temperature for 10 min, and pH 9.0 Tris-HCl neutralization buffer was added, followed by infection into SS320 cells at 37°C, with an infection time of 45 min. Then 50μl 2E12 / ml M13K07 helper phage (NEB, Cat. No. N0315S) was added to the infected cells, and finally fresh 2xYT (containing 100μg / ml Amp, 50μg / ml Kan, 1mM IPTG) was added and incubated at 30°C overnight. The overnight culture was centrifuged, the supernatant was collected, and 20% PEG6000 / 2.5M NaCl was added to the supernatant (1:5, volume ratio), followed by centrifugation at 8000 rpm at 4°C for 20 min. The phage precipitate obtained after centrifugation was resuspended in 1 ml of 1x PBS. The resulting supernatant (phage granules) was transferred to a new tube to prepare the second panning. The process of the second and third panning was the same as the procedure described above.

[0339] 4.3 Initial Screening Colonies were selected into 96-well plates containing 2YT / AMP medium (Sangon Biotech, Cat. No. A507016-0250) and grown for 3 hours at 37°C. IPTG was added to a final concentration of 1 mM and induced overnight at 30°C. After that, the supernatant was centrifuged and precipitated, and the supernatant was taken for ELISA and FACS testing.

[0340] 4.4 Confirmation of positive clones After sequencing analysis, the positive clones were subjected to IPTG-induced expression again. The expressed proteins were first quantified by quantitative ELISA, and then FACS identification was performed. The FACS identification results were combined with the sequence information to analyze the mutation hotspots.

[0341] 4.5 Identification of combinatorial mutant molecules Combinatorial mutations were designed according to the hot spots, and a total of six mutants were constructed into mammalian expression vectors for protein expression and purification, after which the purified mutants were identified using FACS.

[0342] Of the PR004666 mutants obtained, PR005750, PR005751, PR005752, PR005753, PR005754, PR005763 and PR005787 are Fab antibodies, PR006154, PR006155, PR006156, PR006157, PR006161 and PR006166 are IgG antibodies having a "DE" mutation in the IgG1 constant region, and PR005565, PR006272, PR006276, PR006273, PR006277, PR006274 and PR006275 are IgG antibodies with an IgG1 constant region, and their SEQ ID NOs are shown in Table 30 below, and their CDR sequences are shown in Table 31 below. [Table 30] [Table 31]

[0343] Example 5 Antibody Expression and Purification This example introduces a general method for producing antibodies using mammalian host cells (e.g., human embryonic kidney cells HEK293 or Chinese hamster ovary cells CHO and their derivatives), techniques such as instantaneous transfection expression and affinity capture separation. The method is applicable to target antibodies that contain an Fc region; the target antibody can be composed of one or more protein polypeptide chains; and can be derived from one or more expression plasmids.

[0344] The amino acid sequence of the antibody polypeptide chain is converted into a nucleotide sequence by codon optimization; the encoded nucleotide sequence is synthesized and cloned into an expression vector compatible with the host cell. The plasmids encoding the antibody polypeptide chain are co-transfected into mammalian host cells in a specific ratio, and recombinant antibodies with correct folding and assembly of the polypeptide chain can be obtained by utilizing conventional recombinant protein expression and purification techniques. Specifically, ExpiCHO-S TM ExpiCHO cells TM The cells were spread in Expression Medium (Gibco, #A2910001). Before the start of instantaneous transfection, the cell concentration was adjusted to 3 × 10 6 -4×10 6 The cells were adjusted to 7 × 10 cells / ml and cultured in an 8% CO2 shaker at 37°C for 24 hours to a cell concentration of 7 × 10 6 -10×10 6 Adjust to 6 x 10 cells / ml and 6 The plasmids encoding the antibody polypeptide chains were mixed in a fixed ratio, and a total of 8 μg of plasmid (plasmid to cell ratio of 0.8 μg:1 ml) was added to 0.4 ml of OptiPRO TM Dissolved in SFM medium and sterilized by filtering through a 0.22 μm filter membrane. TM Take CHO reagent (Gibco, #A29129) and mix with 0.37 ml of OptiPRO TM Add ExpiFectamine to SFM medium immediately. TMThe CHO reagent solution was slowly added to the plasmid solution, mixed evenly by inversion, and the mixture of plasmid and transfection reagent was slowly dripped into the culture flask while shaking. In the process of producing afucosylated (AF) protein, it is necessary to immediately drip DMSO solution of 2FF ((2-fluoro peracetylated fucose), synthesized by WUXI APPTEC) into the culture flask slowly to a final concentration of 50 μM, and rock while dripping. The cells were cultured for 8-9 days in a 8% CO2 shaker at 37 °C. After 8 days, the cell viability was observed. The culture was collected and centrifuged at a rotation speed of 3300g for 10 minutes, after which the supernatant was taken; the supernatant was then centrifuged at high speed to remove impurities. MabSelect was added in PBS pH 7.4 buffer. TM The gravity column containing the antibody was equilibrated and washed with 2-5 times the column volume. The supernatant sample was passed through the column; the column was washed with 5-10 times the column volume of PBS buffer, and then the target protein was eluted with 0.1 M glycine at pH 3.5, then neutralized with Tris-HCl at pH 8.0, and finally concentrated in an ultrafiltration tube and converted into PBS buffer to obtain the purified recombinant antibody solution. Finally, the purified recombinant antibody solution was purified by NanoDrop (Thermo Scientific TM NanoDrop TM The concentrations were measured using a 100% ethanol centrifuge, subpackaged, and stored for future use.

[0345] Example 6 The antigen binding proteins of the present application can bind to human CCR8 (FACS) Cells overexpressing human CCR8 were digested with pancreatin, counted and resuspended until the cell density was 1E6 / ml. 100μl / well of the cell suspension was added to a V-bottom 96-well plate, centrifuged at 300g for 5 minutes, and the supernatant was removed. The anti-CCR8 antibody provided by the present invention was used as the primary antibody, starting at 200nM and diluted in a 5-fold gradient with FACS buffer (DPBS containing 2% FBS). The cells were resuspended with the diluted primary antibody and incubated at 4℃ for 1 hour at 100ul / well. Washed twice with DPBS, centrifuged at 300×g for 5 minutes, and the supernatant was removed. Secondary antibody diluted 1:1000 in FACS buffer was added at 100ul / well, and the cells were resuspended and then incubated at 4℃ for 40 minutes. Washed twice with DPBS, centrifuged at 300×g for 5 minutes, and the supernatant was removed. The cells were resuspended in 200 μl / well of DPBS and then analyzed using a FACS machine.

[0346] The results of detecting the binding of the CCR8 chimeric antibody to the cell lines overexpressing human CCR8 are shown in Figures 1A-1D. The chimeric antibody molecules PR004120, PR004121, PR004122, PR004123, PR004124, PR004125, PR004126, PR004127, PR004128, PR004129, PR004130, and PR004131 bind to the CHO-K1 cell line (Table 32, Figure 1A), HEK293 cell line (Table 32, Figure 1B), and Baf3 cell line (Table 32, Figure 1C), all of which overexpress human CCR8. ) with EC50 values ​​of 0.25-0.56 nM, 0.34-1.1 nM, and 0.06-0.26 nM in the respective cell lines; CCR8 chimeric antibodies PR005329, PR005330, PR005332, and PR005333 have strong binding activity to human CCR8-overexpressing cell lines with their EC50 values ​​ranging from 0.47 to 0.63 nM (Table 32, Figure 1D). [Table 32] [Table 33]

[0347] The CCR8-enhanced ADCC antibody molecules PR004249, PR004250, PR004251, and PR004252 have strong binding activity to human CCR8-overexpressing HEK293 cell lines (Figure 2), and their EC50 values ​​are between 0.98 and 3.69 nM (Table 34). [Table 34]

[0348] As shown in Figure 3 and Table 35, single-site PTM mutant molecules PR004324, PR004325, PR004326, PR004327, PR004328, and PR004329 of the CCR8 chimeric antibody PR004128, and semi-humanized heavy chain molecules PR004330, PR004331, PR004332, PR004333, PR004334, PR004335, and PR004336 of the CCR8 chimeric antibody PR004128. PR04336, PR004337, PR004338, and the semi-humanized light chain molecules of CCR8 chimeric antibody PR004128, PR004339, PR004340, PR004342, PR004343, PR004344, PR004345, and PR004346, all retain strong binding activity to the human CCR8-overexpressing CHO-K1 cell line, with their EC50 values ​​ranging from 0.17 to 1.33 nM. [Table 35]

[0349] The CCR8 humanized antibody molecules PR004519, PR004520, PR004521, PR004522, PR004523, PR004524, PR004525, PR004526 and PR004527 (Figure 4, Table 36), PR004668, PR004669 (Figure 5, Table 37) all showed strong binding activity to the human CCR8-overexpressing CHO-K1 cell line, with their EC50 of 0.62nM and 0.72nM. [Table 36] [Table 37]

[0350] The CCR8 humanized antibody molecules PR004660, PR004661, PR004662, PR004663, PR004664, PR004665, PR004666, and PR004667 (Figure 6, Table 38) with removed PTM sites retain strong binding activity to the human CCR8 overexpressing CHO-K1 cell line, with their EC50 ranging from 0.28 to 0.68 nM. [Table 38]

[0351] The CCR8 fully human antibody molecules PR005125, PR005128, PR005331, PR005335, and PR005336 showed binding activity to the human CCR8 overexpressing CHO-K1 cell line with EC50 between 0.32-0.47 nM (Table 39), and PR005124 and PR005127 showed binding activity (Figures 7A and 7B). The CCR8 fully human antibody molecule PR004122 showed binding activity to the human CCR8 overexpressing HEK293 cell line (Figure 7C). [Table 39]

[0352] The single cell clone CCR8 fully human antibodies PR004974, PR004970 and PR005293 showed binding activity to the overexpressing CHO-K1 cell line (Figures 8A and 8B).

[0353] Compared with the saturation mutant antibodies PR005170, PR005171, and PR005172 that were mutated at position 96 of the light chain of PR004128, PR004128 retained binding activity to the human CCR8-overexpressing cell line CHO-K1 (FIG. 9).

[0354] PR004666 affinity matured Fab binding domain mutants PR005751, PR005752, PR005753, PR005754, PR005763, PR005787 (PR005750 is the Fab form of the same variable region of PR004666) (Figure 10A) and its full IgG mutants PR006154, PR006155, PR006156, PR006157, PR006161, PR006166 (Figure 10B) showed high binding to overexpressing CHO-K1 cell line. The EC50 of the affinity matured Fab binding domain mutants is between 0.62 and 1.56 nM (Figure 10A and Table 40), and the EC50 of the full IgG mutants is between 0.38 and 0.73 nM (Figure 10B and Table 41). [Table 40] [Table 41]

[0355] Affinity matured variants of PR005565, PR006275 and PR006276, and the defucosylated forms of PR005565, antibodies PR005565AF, PR006275AF, and PR006276AF, exhibit binding activity to overexpressing CHO-K1 cell lines with EC50 values ​​between 0.38 and 0.40 nM (Figure 11 and Table 42). [Table 42]

[0356] Example 7 The antigen binding proteins of the present application can bind to monkey CCR8 (FACS) Cells CHO-K1-CynoCCR8 overexpressing cynomolgus monkey CCR8 were digested with pancreatin, counted and resuspended until the cell density was 1E6 / ml. 100μl / well of the cell suspension was added to a V-bottom 96-well plate, centrifuged at 300g for 5 minutes, and the supernatant was removed. The anti-CCR8 antibody provided by the present invention was used as the primary antibody, starting at 200nM and diluted in a 5-fold gradient with FACS buffer (DPBS containing 2% FBS). The cells were resuspended with the diluted primary antibody and incubated at 4℃ for 1 hour at 100ul / well. The cells were washed twice with DPBS, centrifuged at 300×g for 5 minutes, and the supernatant was removed. The cells were resuspended with 100ul / well of the secondary antibody diluted 1:1000 in FACS buffer, then incubated at 4℃ for 40 minutes. The cells were washed twice with DPBS, centrifuged at 300×g for 5 minutes, and the supernatant was removed. The cells were resuspended in 200 μl / well of DPBS and then analyzed using a FACS machine.

[0357] Among them, the CCR8 chimeric antibody molecules PR004122, PR004125, PR004128 and PR004131 exhibited strong binding activity to the CHO-K1 cell line overexpressing monkey CCR8, and their EC50 values ​​were between 0.83 and 1.6 nM, as shown in FIG. 12, Table 43. The CCR8-enhanced ADCC antibody molecules PR004249, PR004250, PR004251 and PR004252 (FIG. 13, Table 44), the PTM mutant molecules PR004324, PR004325, PR004326, PR004327, PR004328 and PR004329 of the CCR8 chimeric antibody PR004128, the semi-humanized antibody molecules PR004330, PR004331 of the CCR8 chimeric antibody PR004128, and the CCR8 chimeric antibody molecules PR004332, PR004333, PR004334, PR004335, PR004336, PR004327, PR004328 and PR004329, and the CCR8 chimeric antibody PR004128 semi-humanized antibody molecules PR004330, PR004331, PR004332, PR004333, PR004334, PR004335, PR004336, PR004337, PR004338, PR004339, and PR004340, respectively, exhibited strong binding activity to the CHO-K1 cell line overexpressing monkey CCR8, and their EC50 values ​​were between 0.83 and 1.6 nM, as shown in FIG. 12, Table 43. 04331, PR004332, PR004333, PR004334, PR004335, PR004336, PR004337, PR004338, PR004339, PR004340, PR004343, PR004344 and PR004345 (Figure 14, Table 45), whereas in Figure 14, Table 45, the mutant molecules PR004342 and PR004346 lost their cross-binding activity with monkey CCR8. Regarding the CCR8 humanized antibody molecules PR004519, PR004520, PR004521, PR004522, PR004523, PR004524, PR004525, PR004526 and PR004527 (Figure 15, Table 46), and the humanized antibody molecules PR004668 and PR004669 (Figure 16, Table 46), these antibody molecules have strong binding to the CHO-K1 cell line overexpressing monkey CCR8 and have cross-binding activity with monkey CCR8, and their EC50 are between 4.01 and 7.33 nM. The humanized molecules PR004660, PR004661, PR004662, PR004663, PR004664, PR004665, PR004666 and PR004667, in which the PTM of PR04128 was removed, all retained cross-binding activity with monkeys (Figure 17). [Table 43] [Table 44] [Table 45] [Table 46]

[0358] Compared with the saturation mutated antibodies PR005170, PR005171 and PR005172 at position 96 of the light chain of PR004128, PR004128 still retained binding activity to monkey CCR8-overexpressing cell lines (FIG. 18).

[0359] Affinity matured variants of PR004666, PR006154, PR006155, PR006156, PR006157, PR006161 and PR006166, exhibit higher binding to CHO-K1 cell lines overexpressing monkey CCR8, with their EC50s between 0.31 and 0.44 nM (Figure 19 and Table 47). [Table 47]

[0360] The affinity matured variants of PR005565, PR006275 and PR006276, and the affinity matured variants of PR005565AF, PR006275AF and PR006276AF, exhibit binding activity to CHO-K1 cell lines overexpressing monkey CCR8, with their EC50s ranging from 0.47 to 0.51 nM (Figure 20 and Table 48). [Table 48]

[0361] Example 8. Affinity detection of the antigen-binding proteins of the present application 30μg Goat Anti-Human IgG Fc antibody was added to 200mg PMMA hard beads, and coating solution was added up to 1.0mL, the buffer composition was 1xPBS, pH 7.4, and it was confirmed that the beads were completely suspended in the solution. After rotating the beads for 2 hours at room temperature, the beads were allowed to settle naturally or centrifuged briefly at low speed and the supernatant was removed. 1mL of blocking buffer (1xPBS, pH 7.4, containing 10mg / mL BSA), resuspend the beads in blocking solution, and ensure that the beads were rotated for 1 hour at room temperature. Appropriate concentrations of PR005565, PR006155 or PR006166 were used as the 100% signal value, and the PBS blank was used as the background value. Alexa 647 Goat

[0362] Anti-Human IgG 0.5ug / ml was used to detect net signal value. Cell lines overexpressing human or monkey CCR8 were harvested by centrifugation at 1500g for 5 minutes, washed twice with 2PBS, then centrifuged at 350g, and cells were harvested in 1.5 ml centrifuge tubes. 10ml of 0.2nM PR005565, PR006155 or PR006166 solution was prepared, and the whole cells were supplemented to 0.82mL with 0.2nM PR005565, PR006155 or PR006166 solution, and the cells were diluted in a 2-fold gradient with 0.2nM PR005565, PR006155 or PR006166 as buffer. Cells were incubated with 0.2nM PR005565, PR006155 or PR006166 suspension for 3 hours with shaking at room temperature. Then, the mixture was centrifuged at 350g for 5 min, and the supernatant was collected. 10 ml of Alexa 647 Goat Anti-Human IgG solution was prepared, and the samples were placed in the corresponding positions in the tube rack. The "Start" button of the instrument KinExA 4000 (Sapidyne Instruments Inc.) was clicked. The affinity constant of PR005565 and the cell line overexpressing human CCR8 was 129.55 pM, with a 95% confidence interval range of 36.18 pM-374.42 pM. The affinity constant of PR005565 and the cell line overexpressing monkey CCR8 was 177.27 pM, with a 95% confidence interval range of 65.22 pM-536.39 pM. The affinity constant of PR006155 and the cell line overexpressing human CCR8 was 21.35 pM, with a 95% confidence interval range of 7.96 pM-35.46 pM. The affinity constant of PR006166 to the cell line overexpressing human CCR8 was 49.29 pM, with a 95% confidence interval range of 25.63 pM-87.38 pM.

[0363] Example 9 The antigen binding proteins of the present application can block calcium flux signals Human CCR8-overexpressing cells CHO-K1-Gα16-hCCR8 were seeded into a 96-well black-bottom plate at a density of 250,000 cells / well and cultured overnight in a 37°C incubator. The next day, the culture medium in the 96-well plate was discarded, and 50 μl of dyeing calcium buffer containing 2 μM Fluo-4AM was added to each well freshly and incubated at 37°C for 50 minutes. The dyeing calcium buffer was removed and washed once with washing buffer at 50 μl / well. The antibody to be measured was gradient-diluted to three concentrations of 200 nM, 20 nM, and 2 nM with 1×HBSS buffer. 50 μl of the diluted antibody was added to the 96-well plate and incubated for 20 minutes. 25 μl of human CCL1 was added to each well, and the intracellular calcium flux signal was read for 80 seconds with an excitation light of 485 nm and an absorption light of 525 nm on a FlexStation II 384 microwell plate reader. Data were analyzed using GraphPad Prism 6.0.

[0364] The results of CCR8 chimeric antibodies blocking intracellular calcium flux signals excited by CCL1 are shown in Figure 21, where molecules PR004120, PR004121, PR004122, PR004123, PR004124, PR004125, PR004126, PR004127, PR004128, PR004129, PR004130 and PR004131 all show good blocking functional activity (Figure 21A). Here, PR004121, PR004122, PR004125, PR004128, PR004131, which have the cross-binding activity of monkey CCR8, have IC50 between 1.16 and 1.67 nM to block intracellular calcium flux by CCL1 (Figure 21B, Table 49). Other CCR8 chimeric antibodies are shown in Figure 22, PR005329, PR005330, PR005332 and PR005333 also show good blocking activity. [Table 49]

[0365] The results of blocking the intracellular calcium flux signal induced by CCL1 by chimeric antibodies with CCR8-enhanced ADCC function are shown in FIG. 23, and the molecules PR004249, PR004250, PR004251 and PR004252 all retained good blocking function activity.

[0366] The CCR8 humanized antibodies PR004668, PR004669, PR004520, and PR004525 all retained good calcium current blocking activity (Figure 24). The PTM site-deleted humanized antibodies PR004660, PR004661, PR004662, PR004663, PR004664, PR004665, PR004666, and PR004667 of PR004128 all retained calcium current blocking activity (Figure 25).

[0367] The fully human antibodies PR005125 and PR005128 also have the function of blocking intracellular calcium flux induced by CCL1 (Figure 26). Saturation mutant antibodies PR005170, PR005171, and PR005172 at position 96 of the light chain of RP004128 have good calcium flux blocking activity (Figure 27).

[0368] Example 10 The antigen binding proteins of the present application are capable of blocking CCL1-mediated cell migration Human CCR8-overexpressing cells Baf3-hCCR8 were resuspended in RPMI 1640 medium containing 0.2% BSA as the assay buffer, and the concentration was adjusted to 2E6 / ml. The antibody to be measured was gradient-diluted (2x) in the assay buffer to three final concentrations of 200 nM, 20 nM, and 2 nM. The cells and antibody were mixed at a ratio of 1:1 and incubated at 37°C for 30 minutes. The ligand CCL1 was gradient-diluted in the assay buffer, and 150 μl / well was added to the lower chamber of a Transwell plate (Corning, Cat NO:3387), with a blank buffer well set up as a negative control. The incubated antibody-cell mixture was added to the upper chamber of the Transwell plate at 100 μl / well, with a cell-only well set up as a positive control. The Trans well plate was placed in an incubator and incubated. After 5 h, the Trans well plate was removed, the cells that had migrated to the lower chamber were gently resuspended, and 100 μl was transferred to a black lower 96 well plate (PerkinElmer, Cat No: 6005225). Cell-Titer glo (PerkinElmer, Cat No: G7573) was added at 100 μl / well and allowed to act for 10 minutes, and the luminancence (RLU) was read using a plate reader. The formula for the inhibition rate ratio (%) is as follows:

[0369] Inhibition ratio (%) = [RLU (positive control well) - RLU (sample well)] / [RLU (positive control well) - RLU (negative control well)] x 100

[0370] The results of the cell migration blocking function activity measurement of CCR8 chimeric antibodies are shown in Figure 28A-28B, and the molecules PR004120, PR004121, PR004122, PR004123, PR004124, PR004125, PR004126, PR004127, PR004128, PR004129, PR004130 and PR004131 can all block CCL1-mediated cell migration, showing good blocking function activity. Other CCR8 chimeric antibodies are shown in Figure 29, and PR005329, PR005330, PR005332 and PR005333 also showed good blocking function activity.

[0371] CCR8 enhancing ADCC antibody results are shown in Figures 30A-30C, and show that PR004249, PR004250, PR004251 and PR004252 all retained functional activity in blocking CCL1 mediated cell migration.

[0372] The CCR8 chimeric antibody molecule PR004128 mutant molecules PR004324, PR004326, PR004329, PR004330, PR004333, PR004336, PR004339, PR004340 and PR004343 (Figures 31A-31C) all retained the functional activity of blocking CCL1-mediated cell migration. The humanized antibody molecules PR004519, PR004520, PR004521, PR004522, PR004523, PR004524, PR004525, PR004526, PR004527, PR004668 and PR004669 (Figures 32A-32C) all have the functional activity of blocking CCL1-mediated cell migration.

[0373] The PTM site-deleted humanized antibodies PR004662 and PR00466 retained the functional activity of CCL1-mediated cell migration (FIG. 33).

[0374] The fully human antibodies PR005125, PR005128, PR005331, PR005335, PR005336 and PR004520 also have functional activity capable of blocking CCL1-mediated cell migration (Figures 34A and 34B).

[0375] Example 11 Antibody-antigen epitope competitive binding assay Conjugated antibodies with Sulfo-NHS-LC-Biotin at a molar ratio of 5:1 (1 mol of antibody is added with 5 mol of Sulfo-NHS-LC-Biotin) according to the product instructions (ThermoFisher, Cat NO: A39257) and incubated on ice for 2 hours. Conjugated antibodies were purified using Zeba desalting columns (ThermoFisher, Cat NO: 89882). Cells HEK293-hCCR8 overexpressing human CCR8 were added to a V-bottom 96-well plate according to a density of 1E5 / well, centrifuged at 300g for 5 minutes, and the supernatant was removed. Competitive antibodies were serially diluted 1:10 in 8 points starting from 200 nM to take a mixed competitive antibody with a binding EC80 concentration of 1:1 on the HEK293 cell line overexpressing human CCR8 of Biotin-antibody. The cells were resuspended in 96-well plates and incubated at 4°C for 1 hour. The cells were washed twice with DPBS at 200 μl / well. Secondary antibodies diluted 1:1000 were added at 100 μl / well and incubated at 4°C for 40 minutes. The cells were washed twice with DPBS at 200 μl / well. Finally, the cells were resuspended in DPBS at 200 μl / well and analyzed by FACS instrument. Competitive antibodies were explained as two antibodies binding to the same or close antigen-binding epitopes if they could compete with the antibody-binding antigen conjugated with biotin.

[0376] The results of the competitive binding of the CCR8 chimeric antibody to the antigen epitope are shown in Figures 35A-35E. The results showed that the molecules PR004121, PR004122, PR004125, PR004128 and PR004131 all bound to the same CCR8 antigen epitope.

[0377] Example 12 The antigen binding proteins of the present application have the biological activity of an ADCC reporter gene CHO-K1-hCCR overexpressing human CCR8 were digested and harvested, counted and resuspended in RPMI 1640 with 4% FBS, and added to a white ViewPlate 96-well plate (PerkinElmer, Cat No: 6005181). Jurkat / FcγR III-NFAT cells (Vazyme, Cat No: DD1301-01) were harvested, counted and resuspended in RPMI 1640 with 4% FBS, and added to a white ViewPlate 96-well plate (E / T ratio=5). The antibodies to be measured were serially gradient diluted in RPMI 1640 with 4% FBS, with an initial concentration of 200 nM and 8 concentrations serially diluted 10-fold. 50 μl / well of the diluted antibodies were added to a white ViewPlate 96-well plate. The 96-well plate was incubated in a 37°C incubator for 6 h, then transferred to room temperature for 30 min to equilibrate, 75 μl / well One-Glo (PerkinElmer, Cat NO:E6120) was added and incubated for 10 min, and RLU was read on a plate reader. Data were analyzed using GraphPad Prism 6.0.

[0378] The results of measuring the biological activity of the ADCC reporter gene of the CCR8 chimeric antibody molecule PR004125 and its increased ADCC antibody molecule PR004250 are shown in Figure 36. The results showed that both PR004125 and PR004250 had strong ADCC effects, with the EC50 of PR004250 being 0.04 nM and the EC50 of PR004125 being 0.59 nM.

[0379] The results of measuring the biological activity of the ADCC reporter gene of the affinity matured mutants PR006275AF and PR006276AF of PR005565AF are shown in Figure 37. As a result, both PR00PR006275AF and PR006276AF had strong ADCC effects, where the EC50 of R00PR006275AF was 2.60 nM and the EC50 of PR006276AF was 1.66 nM.

[0380] Example 13 NK cell-mediated ADCC biological activity CHO-K1-hCCR8 overexpressing human CCR8 were digested, harvested, counted and resuspended in RPMI 1640 with 2% FBS, and added to a 96-well plate (Corning, Cat No: 3599) at 10000cells / 25ul / well. Fresh or cryopreserved PBMC cells were harvested, counted and resuspended in RPMI 1640 with 2% FBS, and added to a 96-well plate at 250000cells / 25ul / well (E / T ratio=25). Antibodies to be measured were serially gradient diluted (2x final concentration) in RPMI 1640 with 2% FBS, with an initial concentration of 2 nM and six concentrations serially diluted 10-fold. The diluted antibodies were added to a 96-well plate at 50ul / well, and the whole system was incubated in a 37°C incubator for 6 hours. According to the kit (Promega, Cat No: G1781) instruction manual, 10 ul of lysis solution (10x) was added to the corresponding control wells 45 minutes before the end of incubation. At the end of 6 hours of incubation, the culture plate was centrifuged at 250g for 4 minutes, 50 ul of the supernatant was taken, 50 ul of the mixed substrate prepared in the kit was added, incubated at 37 degrees for 15-30 minutes, and the reading was taken at 490 nm with a microplate reader. The killing percentage was calculated according to the formula in the specification. The data was analyzed with GraphPad Prism 6.0.

[0381] As shown in Figures 38A-38E, PR004668, PR004669, PR004519, PR004520, PR004525, the PTM-removed humanized antibody PR004666, the fully human antibody molecules PR005125 and PR005128, and the fully human antibody molecule PR004974 derived from a single cell clone all have strong ADCC biological activity.

[0382] As shown in Figure 39, both affinity matured variants of PR004666, PR006155 and PR006166, have potent ADCC biological activity.

[0383] Example 14 Differential expression of CCR8 in human tumor-infiltrating lymphocyte-derived Treg (TIL-Treg) and normal human PBMC-derived Treg Human clear cell renal cell carcinoma (ccRCC) and breast cancer (BC) derived TIL cells were resuspended in medium that had been restored to room temperature and counted using a cell counter. First, cells were treated with Live / Dead cell viability dye for 30 minutes; then cells were treated with Fc receptor blocking agent for 15 minutes; then, a set of antibodies was diluted in staining buffer to a certain concentration for cell surface staining: CD45 antibody, CD3 antibody, CD4 antibody, PR004666 antibody. Then, FoxP3 staining in the cell nucleus was performed using a FoxP3 staining kit. After staining, samples were analyzed using a flow cytometer.

[0384] As shown in FIG. 40, CCR8 was hardly expressed in Tregs derived from normal human PBMCs, but was highly expressed in Tregs derived from human tumor-infiltrating lymphocytes.

[0385] Example 15 PR005565 specific binding experiment To identify PR005565 binding targets, approximately 6000 different membrane proteins were expressed in a single well of HEK-293T or QT6 cells arrayed in a 384-well plate. Then, a matrix was formed by combining the independent columns and rows of each 384-well plate, and a unique combination of two different wells in the matrix plate represented each type of protein. Protein targets were identified by detecting the binding of PR005565 to the overlapping pools of columns and rows, thereby performing specific deconvolution. Each membrane protein target was assigned a value, which corresponds to the binding value of its unique pool of rows and columns, and then target proteins that showed binding values ​​in both holes greater than three standard deviations of the background value were selected for downstream validation experiments. The paired binding data generated were then normalized and transformed to obtain a single data set of PR005565 binding to each protein. Values ​​lower than three standard deviations of the average background value were defined as non-specific fluorescence. Target proteins bound to PR005565 were then identified.

[0386] In 384-well plates, cells were transfected with plasmids that bound these target proteins (MMP16, CD40LG, CD147, TSPAN4, TSPAN12), protein A or empty vector. PR005565 was added to the transfected cells in 4-fold dilutions starting from 20 μg / ml and incubated, and then their binding was detected using high-throughput immunofluorescence flow cytometry. At the same time, in a single experiment, after cell transfection with CCR8 vector, PR005565 or a commercial anti-CCR8 antibody (Biolegend, Cat N360602) could be bound, as shown in Figure 41A and Figure 41B.

[0387] Then, HEK293 cells were transfected with commercially available MMP 16 (protein information can be found in Uniprot P51512), CD40LG (protein information can be found in Uniprot P29965), CD147 (protein information can be found in Uniprot P35612), TSPAN4 (protein information can be found in Uniprot O14817), and TSPAN12 (protein information can be found in Uniprot O95859) plasmids, and the binding of PR005565, PR006275, and PR006276 to these proteins was verified. The results showed that MMP16, CD40LG, and CD147 could clearly bind to their specific antibodies, and TSPAN4-FLAG and TSPAN12-FLAG could specifically bind to anti-FLAG antibodies, proving that the transient overexpression of proteins was successful. However, the binding values ​​of PR005565, PR006275 and PR006276 to MMP16, CD40LG, CD147, TSPAN4 and TSPAN12 after transfection of HEK293 cells all matched the signal values ​​of HEK293 cells themselves. Therefore, PR005565, PR006275 and PR006276 do not bind non-specifically to MMP16, CD40LG, CD147, TSPAN4 and TSPAN12 proteins (see Table 50). This explains that the antigen-binding protein of the present application does not bind to non-CCR8 antigens. [Table 50]

[0388] Example 16 In vivo tumor inhibition experiment of PR004520 in mice On the day of cell inoculation, each NCG mouse was 7 MDA-MB-231 tumor cells were inoculated subcutaneously. The cells were resuspended in a mixture of PBS and Matrigel (1:1) (0.1 mL / mouse) and inoculated subcutaneously. The average tumor volume in mice was 102 mm 3 When the number of mice reached 10, the 36 mice were divided into 6 groups and each mouse was given 5x10 6Human PBMCs were inoculated intravenously, and the cells were resuspended in 200 ul of PBS. The administration was started the next day, with an administration cycle of once every two weeks, for a total of six administrations, administered intraperitoneally. After the administration started, the body weight and tumor volume were measured twice a week, and the calculation method for tumor volume was as follows: tumor volume (mm 3 ) = 0.5 × tumor long axis × tumor short axis 2 Experimental observations were terminated on the 22nd day after administration, after which all mice were euthanized. Data were analyzed using Graphpad Prism 8.0 with one-way ANOVA.

[0389] As shown in Figure 42, the mean tumor volume of the control group mice on day 22 after treatment was 1248 mm 3 In the PR004520 (10 mg / kg) treatment group, the mean tumor volume 22 days after administration was 883 mm 3 The mean tumor volume in the Keytruda (10 mg / kg) treatment group on the 22nd day after administration was 963 mm 3 The mean tumor volume in the Tecentriq (1 mg / kg) treatment group on the 22nd day after administration was 771 mm 3 The mean tumor volume at day 22 after administration was 581 mm3 in the combination treatment group PR004520 (10 mg / kg) and Keytruda (10 mg / kg) treatment groups. 3 The mean tumor volume on the 22nd day after administration was 745 mm in the combination treatment group PR004520 (10 mg / kg) and Tecentriq (1 mg / kg) treatment groups. 3The tumor inhibition rate (TGI) (%) was 40.32%, which was significantly different from the vehicle control group (p-value 0.004). The combination treatment group PR004520 (10 mg / kg) and Keytruda (10 mg / kg) treatment groups were not significantly different from the PR004520 (10 mg / kg) single drug group and Keytruda (10 mg / kg) single drug group. The combination treatment group PR004520 (10 mg / kg) and Tecentriq (1 mg / kg) treatment groups were not significantly different from the PR004520 (10 mg / kg) single drug group and Tecentriq (1 mg / kg) single drug group.

[0390] Example 17 In vivo tumor inhibition experiments in mice with PR004520, PR004525 and PR004668 On the day of cell inoculation, each NCG mouse was 7 MDA-MB-231 tumor cells were inoculated subcutaneously. The cells were resuspended in a mixture of PBS and Matrigel (1:1) (0.1 mL / mouse) and inoculated subcutaneously. The average tumor volume of the mice was 100 mm 3 When the number of mice reached 10, the 60 mice were divided into 10 groups and each mouse was given 5x10 6 Human PBMCs were inoculated intravenously, and the cells were resuspended in 200 ul of PBS. The administration was started the next day, with an administration cycle of once every two weeks, for a total of six administrations, administered intraperitoneally. After the administration started, the body weight and tumor volume were measured twice a week, and the calculation method for tumor volume was as follows: tumor volume (mm 3 ) = 0.5 × tumor long axis × tumor short axis 2 Experimental observations were terminated on the 20th day after administration, after which all mice were euthanized. Data were analyzed using Graphpad Prism 8.0 with one-way ANOVA.

[0391] As shown in Figure 43, the mean tumor volume in the control group of mice 20 days after administration was 1217 mm 3 In the PR004520 (30 mg / kg) treatment group, the mean tumor volume 20 days after administration was 958 mm 3There was no significant difference compared to the vehicle control group (p value was 0.354), and the tumor inhibition rate TGI (%) was 21.29%. The PR004525 (30 mg / kg) treatment group had a mean tumor volume of 706 mm on the 20th day after administration. 3 The mean tumor volume in the PR004668 (30 mg / kg) treatment group on the 20th day after administration was 671 mm 3 The mean tumor volume in the Keytruda (10 mg / kg) treatment group on the 20th day after administration was 892 mm 3 The mean tumor volume on the 20th day after administration in the combination treatment group, PR004520 (30 mg / kg) and Keytruda (10 mg / kg), was 564 mm 3 The mean tumor volume at day 20 after administration in the combination treatment group PR004525 (30 mg / kg) and Keytruda (10 mg / kg) was 482 mm3, which was significantly different from the control group (p value < 0.0001), and the tumor inhibition rate TGI (%) was 53.65%. .... 3 The mean tumor volume at day 20 after administration in the combination treatment group PR004668 (30 mg / kg) and Keytruda (10 mg / kg) was 441 mm, which was significantly different from the control group (p value < 0.0001), and the tumor inhibition rate TGI (%) was 60.39%. The mean tumor volume at day 20 after administration in the combination treatment group PR004668 (30 mg / kg) and Keytruda (10 mg / kg) was 441 mm. 3There was a significant difference compared to the control group (p value was 0.0001), and the tumor inhibition rate TGI (%) was 63.77%. There was no significant difference compared to the single drug group of PR004668 (30 mg / kg) (p value was 0.161), and no significant difference compared to the single drug group of Keytruda (10 mg / kg) (p value was 0.056).

[0392] Example 18 In vivo tumor inhibition study of PR005565AF as a single drug and in combination with anti-mouse PD-1 and anti-mouse PD-L1 monoclonal antibodies in mice On the day of cell inoculation, 1 × 10 cells were added to each C57BL / 6-CCR8knockin mouse. 6 MC38 tumor cells were inoculated subcutaneously. The cells were resuspended in PBS (0.1 ml / mouse) and inoculated subcutaneously. The average tumor volume in mice was 88 mm 3 When the tumor volume reached 100 mg / kg, 48 mice were divided into 6 groups and administered intraperitoneally. The administration cycle was twice a week, for a total of 6 times. After the administration started, the body weight and tumor volume were measured twice a week, and the calculation method for tumor volume was as follows: tumor volume (mm 3 ) = 0.5 × tumor long axis × tumor short axis 2 One mouse was found dead in the combination treatment group PR005565F (10 mg / kg) + Tecentriq (1 mg / kg) on ​​day 17 after dosing, the body had autolyzed at the time of discovery, and all remaining mice in the group were normal, as were all mice in the other treatment groups. All experimental observations were terminated on day 21 after dosing, and all mice were euthanized. Analysis was performed based on data from day 14 after dosing, using Graphpad Prism 9.0, one-way ANOVA. P<0.05 was defined as significant difference.

[0393] As shown in FIG. 44, the mean tumor volume on day 14 after administration of the control group (IgG1, 3 mg / kg) mice was 884 mm 3 In the PR005565F (10 mg / kg) treatment group, the mean tumor volume 14 days after administration was 421 mm 3The tumor inhibition rate (TGI) (%) was 52.36%. The mean tumor volume of the test drug RPM1-14 (1 mg / kg) treatment group on the 14th day after administration was 572 mm 3 The mean tumor volume in the Tecentriq (1 mg / kg) treatment group on the 14th day after administration was 363 mm 3 The mean tumor volume on the 14th day after administration in the combination treatment group PR005565F (10 mg / kg) + RPM1-14 (1 mg / kg) was 427 mm 3 There was a significant difference compared to the control group (p value was 0.0119), and the tumor inhibition rate TGI (%) was 51.74%. There was no significant difference compared to the PR005565F (10 mg / kg) treatment group (P>0.9999), and no significant difference compared to the RPM1-14 (1 mg / kg) treatment group (P=0.8693). The combination treatment group PR005565F (10 mg / kg) + Tecentriq (1 mg / kg) had a mean tumor volume of 204 mm on the 14th day after administration. 3 There was a significant difference compared to the control group (p<0.0001), and the tumor inhibition rate (TGI) (%) was 76.94%. There was no significant difference compared to the PR005565F (10 mg / kg) treatment group (P=0.5503) or the Tecentriq (1 mg / kg) treatment group (P=0.8184).

[0394] Example 19 In vivo tumor inhibition experiments in mice with PR005565AF, PR006275AF and PR006276AF On the day of cell inoculation, 1 × 10 cells were added to each C57BL / 6-CCR8knockin mouse. 6 MC38 tumor cells were inoculated subcutaneously. Cells were resuspended in PBS (0.1 mL / mouse) and inoculated subcutaneously. The average tumor volume in mice was 90 mm 3When the tumor volume reached 100 mg / kg, 42 mice were divided into 7 groups and administered intraperitoneally. The administration cycle was twice a week, for a total of 5 doses. After administration began, the body weight and tumor volume were weighed twice a week, and the calculation method for tumor volume was as follows: tumor volume (mm 3 ) = 0.5 × tumor long axis × tumor short axis 2 One mouse in the treatment group with the test drug PR006275AF (10 mg / kg) was found dead on the 18th day after administration, and the body had autolyzed when found, while the remaining mice in the same group were in a normal state, and all mice in the other treatment groups were in a normal state. On the 18th day after administration, the observation of the entire study was terminated, and the mice were euthanized. Analysis was based on the data on the 14th day after administration, and independent sample T was used to compare whether there was a significant difference between the different treatment groups and the control group, and the data was analyzed using SPSS. P<0.05 was defined as a significant difference.

[0395] As shown in FIG. 45, the mean tumor volume on day 14 after administration of the control group (IgG1, 3 mg / kg) mice was 1142 mm 3 In the PR005565AF (3 mg / kg) treatment group, the mean tumor volume on the 14th day after administration was 874 mm 3 The mean tumor volume in the PR005565AF (10 mg / kg) treatment group on the 14th day after administration was 561 mm 3 The mean tumor volume in the PR006276AF (3 mg / kg) treatment group on the 14th day after administration was 849 mm 3 There was no significant difference compared to the control group (p value was 0.0973), and the tumor inhibition rate TGI (%) was 25.65%. The mean tumor volume on the 14th day after administration in the test drug PR006276AF (10 mg / kg) treatment group was 563 mm 3The mean tumor volume in the PR006275AF (3 mg / kg) treatment group on the 14th day after administration was 564 mm 3 There was no significant difference compared to the control group (p value was 0.0008), and the tumor inhibition rate TGI (%) was 50.6%. The group treated with the reagent PR006275AF (10 mg / kg) had an average tumor volume of 705 mm on the 14th day after administration. 3 There was no significant difference compared to the control group (p value was 0.0147), and the tumor inhibition rate (TGI) (%) was 38.24%.

Claims

1. 1. An isolated antigen-binding protein that binds to CCR8, comprising an antibody heavy chain or antigen-binding fragment thereof and an antibody light chain or antigen-binding fragment thereof, wherein said antibody heavy chain or antigen-binding fragment thereof comprises HCDR1, HCDR2 and HCDR3, and said antibody light chain or antigen-binding fragment thereof comprises LCDR1, LCDR2 and LCDR3, wherein said HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 and LCDR3 comprise an amino acid sequence selected from any of the following groups: (1) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 80; (2) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 72; (3) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 80; (4) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 38, and HCDR3: SEQ ID NO: 81; (5) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 81; (6) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO: 82; and (7) LCDR1: SEQ ID NO: 111, LCDR2: SEQ ID NO: 127, LCDR3: SEQ ID NO: 142, HCDR1: SEQ ID NO: 22, HCDR2: SEQ ID NO: 48, and HCDR3: SEQ ID NO:

83.

2. The isolated antigen binding protein that binds to CCR8 according to claim 1, comprising an antibody heavy chain variable region VH and an antibody light chain variable region VL, wherein the VH and VL comprise an amino acid sequence selected from any of the following groups: (1) VL: SEQ ID NO: 237 and VH: SEQ ID NO: 207; (2) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 196; (3) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 206; (4) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 208; (5) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 209; (6) VL: SEQ ID NO: 237, and VH: SEQ ID NO: 210; and (7) VL: SEQ ID NO: 237, and VH: SEQ ID NO:

211.

3. Full-length antibody, Fab, Fab', F(ab') 2 3. An isolated antigen-binding protein that binds to CCR8 according to claim 1 or 2, comprising an Fv, scFv, di-scFv, bispecific antibody, and / or a multispecific antibody.

4. 3. An isolated antigen-binding protein that binds to CCR8 according to claim 1 or 2, wherein the antibody is selected from the group consisting of a monoclonal antibody, a chimeric antibody, a humanized antibody and a fully human antibody.

5. The isolated antigen binding protein that binds to CCR8 described in claim 1 or 2, wherein the antigen binding protein further comprises an antibody heavy chain constant region, and the heavy chain constant region is derived from a human IgG constant region.

6. The antigen binding protein comprises an antibody heavy chain and an antibody light chain, (1) the antibody heavy chain comprises the amino acid sequence set forth in SEQ ID NO:317, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO:344; (2) the antibody heavy chain comprises the amino acid sequence set forth in SEQ ID NO:308, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO:344; (3) the antibody heavy chain comprises the amino acid sequence set forth in SEQ ID NO:302, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO:344; (4) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO:281, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO:344; (5) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO:300, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO:344; (6) the antibody heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 299, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO: 344; (7) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO:301, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO:344; (8) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 307, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (9) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 313, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (10) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 303, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (11) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 309, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (12) the antibody heavy chain comprises the amino acid sequence set forth in SEQ ID NO: 314, and the antibody light chain comprises the amino acid sequence set forth in SEQ ID NO: 344; (13) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 304, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (14) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 310, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (15) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 318, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (16) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 315, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (17) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 311, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (18) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 305, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (19) the antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 306, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; (20) The antibody heavy chain comprises the amino acid sequence depicted in SEQ ID NO: 312, and the antibody light chain comprises the amino acid sequence depicted in SEQ ID NO: 344; or (21) The antibody heavy chain comprises the amino acid sequence shown in SEQ ID NO: 316, and the antibody light chain comprises the amino acid sequence shown in SEQ ID NO:

344. An isolated antigen-binding protein that binds to CCR8 according to claim 1 or 2.

7. 7. One or more isolated nucleic acid molecules encoding an isolated antigen binding protein that binds to CCR8 according to any one of claims 1 to 6.

8. A vector comprising the nucleic acid molecule of claim 7.

9. A cell comprising the nucleic acid molecule of claim 7 or the vector of claim 8.

10. A method for producing an isolated antigen-binding protein that binds to CCR8 described in any one of claims 1 to 6, comprising culturing a cell described in claim 9 under conditions that allow expression of the isolated antigen-binding protein that binds to CCR8 described in any one of claims 1 to 6.

11. A chimeric antigen receptor comprising an antigen-binding protein that binds to CCR8 according to any one of claims 1 to 6.

12. A genetically modified cell comprising the chimeric antigen receptor of claim 11.

13. The genetically modified cell described in claim 12, which is an immune cell.

14. 7. An antibody-drug conjugate comprising a cytotoxic agent and an antigen-binding protein that binds to CCR8 described in any one of claims 1 to 6.

15. A composition comprising an isolated antigen binding protein that binds to CCR8 described in any one of claims 1 to 6, a nucleic acid molecule described in claim 7, a vector described in claim 8, a cell described in claim 9, a chimeric antigen receptor described in claim 11, a genetically modified cell described in claim 12 or 13, and / or an antibody drug conjugate described in claim 14, and optionally a pharma- ceutically acceptable vector.

16. A pharmaceutical composition comprising an isolated antigen binding protein that binds to CCR8 as described in any one of claims 1 to 6, a nucleic acid molecule as described in claim 7, a vector as described in claim 8, a cell as described in claim 9, a chimeric antigen receptor as described in claim 11, a genetically modified cell as described in claim 12 or 13, an antibody drug conjugate as described in claim 14 and / or a composition as described in claim 15, for use in the prevention, mitigation and / or treatment of a CCR8-mediated disease or disorder.

17. The pharmaceutical composition of claim 16, wherein the CCR8-mediated disease or disorder is a tumor.

18. The pharmaceutical composition described in claim 17, wherein the tumor is selected from breast cancer, renal cancer, pancreatic cancer, bladder cancer, gastric cancer, cervical cancer and colon cancer.

19. An in vitro method for inhibiting CCL1-induced cell migration, the method comprising contacting the cells with an isolated antigen binding protein that binds to CCR8 described in any one of claims 1 to 6 and / or a composition described in claim 15.

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