Novel anti-CD276 antibodies and uses thereof

Abstract

Anti-CD276 antibody and anti-CD276 / PD-L1 bispecific antibody molecules, isolated polynucleotides encoding them, pharmaceutical compositions containing them and uses thereof are provided.

Description

[Technical field]

[0001] The present disclosure relates generally to novel anti-CD276 antibodies. [Background technology]

[0002] B7-H3 (CD276, UniProt ID for human amino acid sequence: Q5ZPR3 and mouse amino acid sequence: Q8VE98) is a newly discovered important immune checkpoint member of the B7 and CD28 families, which is a type I transmembrane costimulatory molecule that exists in two isoforms determined by the extracellular domain. In mice, the extracellular domain is composed of a single pair of immunoglobulin variable (IgV)-like and immunoglobulin constant (IgC)-like domains, whereas in humans, it is composed of one pair (2Ig-B7-H3) or two identical pairs (4Ig-B7-H3) due to exon duplication. B7-H3 mRNA is widely distributed in most tissues; in contrast, B7-H3 protein has a highly restricted expression on normal tissues due to post-transcriptional regulation by microRNAs. However, the B7-H3 protein is frequently expressed in many different cancer types (60% of all cancers) ("B7-H3: an attractive target for antibody-based immunotherapy". Clinical Cancer Research:clincanres.2584.2020).

[0003] The function of B7-H3 remains controversial. It has been classified as either a costimulatory molecule for T cell activation that inhibits tumor antigen-specific immune responses, or a non-immunological role, such as migration, tumor growth, invasion, metastasis, malignant stage, recurrence rate, angiogenesis, chemoresistance, promoting epithelial to mesenchymal transition, and influencing tumor cell metabolism. The receptor for B7-H3 has been reported to be the triggering receptor expressed on myeloid cells (TREM)-like transcript 2 (TLT-2 or TREML2), which binds to B7-H3 and costimulates activation of CD8 T cells in particular. B7-H3 has also been reported to be an inhibitor for NK cells and osteoblasts by ligating unknown receptors. (The contrasting role of B7-H3, PNAS July 29, 2008, 105(30)10277-10278). Treatment with monoclonal antibodies that block B7-H3 is the major immunotherapeutic strategy for cancer treatment.

[0004] Based on the clinical success of inhibitory immune checkpoint blockade (CTLA-4, PD-1 and PD-L1), mAbs against CD276 appear to be a promising therapeutic strategy worth developing. Due to its selective expression on solid tumors, several groups have generated anti-CD276 antibodies, such as enoblituzumab (MGA271), omburtamab, MGD009, MGC018, DS-7300a and CAR T cells ("B7-H3: an attractive target for antibody-based immunotherapy". Clinical Cancer Research:clincanres.2584.2020), and observed tumor growth inhibition in vitro and in vivo. CD276 has also been reported to be expressed in hematological tumor cells (see Wei Zhang et al., B7 Family Members in Lymphoma: Promising Novel Targets for Tumor Immunotherapy? Front. Oncol., 31 March 2021), indicating that CD276 may also be a potential target for treating hematological cancers.

[0005] Despite the development of therapeutic agents targeting CD276, there is a great need for novel anti-CD276 antibodies. Summary of the Invention

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

[0007] The present disclosure provides novel anti-CD276 antibody molecules, their amino acid and nucleotide sequences, and uses thereof.

[0008] In one aspect, the present disclosure provides SEQ ID NOs: 1-3, 9-11, 17-19, 25-27, 33-35, 41-43, 49-51, 57-59, 65-67, 73-75, 81-83, 89-91, 97-99, 105-107, 113-115, 121-123, 129-131, 137-139, 145-147, 153-155, 161-163, 169-171, 177-179, 185-187, 193-195, 201-203 209-211, 217-219, 225-227, 233-235, 241-243, 249-251, 257-259, 265-267, 273-275, 281-283, 289-291, 297-299, 305-307, 313-315, 321-323, 329-331, 337-339, and 374-375. Row numbers 4-6, 12-14, 20-22, 28-30, 36-38, 44-46, 52-54, 60-62, 68-70, 76-78, 84-86, 92-94, 100-102, 108-110, 116-118, 124-126, 132-134, 140-142, 148-150, 156-158, 164-166, 172-174, 180-181, 188-190, 196-198, 204-206, 212-214, Provided is an isolated antibody or antigen-binding fragment thereof, comprising one, two or three light chain CDR sequences selected from the group consisting of 220-222, 228-230, 236-238, 244-246, 252-254, 260-262, 268-270, 276-278, 284-286, 292-294, 300-302, 308-310, 316-318, 324-326, 332-334, 340-342 and 376-377.

[0009] In some embodiments, the antibody or antigen-binding fragment thereof provided herein comprises: a) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 1 to 3; b) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 9 to 11; c) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 17 to 19; d) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 25 to 27; e) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 33 to 35; f) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 41 to 43; g) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 49 to 51; h) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 57 to 59; i) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 65 to 67; j) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 73 to 75; k) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 81 to 83; l) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 89 to 91; m) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 97 to 99; n) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 105 to 107; o) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 113 to 115; p) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 121 to 123; q) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 129 to 131; r) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 137 to 139; s) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 145 to 147; t) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 153 to 155; u) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 161 to 163; v) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 169 to 171; w) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 177 to 179; x) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 185 to 187; y) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 193 to 195; z) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 201 to 203; aa) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 209 to 211; bb) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 217 to 219; cc) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 225 to 227; dd) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 233 to 235; ee) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 241 to 243; ff) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 249 to 251; gg) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 257 to 259; hh) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 265 to 267; ii) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 273 to 275; jj) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 281 to 283; kk) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 289 to 291; ll) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 297 to 299; mm) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 305 to 307; nn) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 313 to 315; oo) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 321 to 323; pp) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 329 to 331; qq) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 337 to 339; and rr) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 9, 374 and 375; The heavy chain variable region is selected from the group consisting of:

[0010] In some embodiments, the antibody or antigen-binding fragment thereof provided herein comprises: a) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 4 to 6; b) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 12 to 14; c) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 20 to 22; d) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 28 to 30; e) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 36 to 38; f) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 44 to 46; g) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 52 to 54; h) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 60 to 62; i) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 68 to 70; j) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 76 to 78; k) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 84 to 86; l) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 92 to 94; m) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 100 to 102, 108 to 110; n) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 108 to 110; o) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 116 to 118; p) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 124 to 126; q) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 132 to 134; r) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 140 to 142; s) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 148 to 150; t) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 156 to 158; u) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 164 to 166; v) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 172 to 174; w) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 180 to 181; x) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 188 to 190; y) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 196 to 198; z) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 204 to 206; aa) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 212 to 214; bb) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 220 to 222; cc) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 228 to 230; dd) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 236 to 238; ee) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 244 to 246; ff) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 252 to 254; gg) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 260 to 262; hh) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 268 to 270; ii) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 276 to 278; jj) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 284 to 286; kk) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 292 to 294; ll) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 300 to 302; mm) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 308 to 310; nn) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 316 to 318; oo) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 324 to 326; pp) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 332 to 334; qq) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 340 to 342; rr) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 376, 13 and 14; and ss) a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NOs: 377, 45 and 46; The light chain variable region comprises a light chain variable region selected from the group consisting of:

[0011] In some embodiments, the antibody or antigen-binding fragment thereof provided herein comprises: a) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:4, SEQ ID NO:5 and SEQ ID NO:6; b) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:12, SEQ ID NO:13 and SEQ ID NO:14; c) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 17, SEQ ID NO: 18 and SEQ ID NO: 19, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22; d) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:25, SEQ ID NO:26 and SEQ ID NO:27 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:28, SEQ ID NO:29 and SEQ ID NO:30; e) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 33, SEQ ID NO: 34 and SEQ ID NO: 35, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 36, SEQ ID NO: 37 and SEQ ID NO: 38; f) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 41, SEQ ID NO: 42 and SEQ ID NO: 43, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 44, SEQ ID NO: 45 and SEQ ID NO: 46; g) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 49, SEQ ID NO: 50 and SEQ ID NO: 51 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 52, SEQ ID NO: 53 and SEQ ID NO: 54; h) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 57, SEQ ID NO: 58 and SEQ ID NO: 59 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 60, SEQ ID NO: 61 and SEQ ID NO: 62; i) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:65, SEQ ID NO:66 and SEQ ID NO:67, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:68, SEQ ID NO:69 and SEQ ID NO:70; j) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 73, SEQ ID NO: 74 and SEQ ID NO: 75, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 76, SEQ ID NO: 77 and SEQ ID NO: 78; k) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 81, SEQ ID NO: 82 and SEQ ID NO: 83, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 84, SEQ ID NO: 85 and SEQ ID NO: 86; l) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 89, SEQ ID NO: 90 and SEQ ID NO: 91 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 92, SEQ ID NO: 93 and SEQ ID NO: 94; m) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 97, SEQ ID NO: 98 and SEQ ID NO: 99, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 100, SEQ ID NO: 101 and SEQ ID NO: 102; n) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 105, SEQ ID NO: 106 and SEQ ID NO: 107, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 108, SEQ ID NO: 109 and SEQ ID NO: 110; o) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 113, SEQ ID NO: 114 and SEQ ID NO: 115, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 116, SEQ ID NO: 117 and SEQ ID NO: 118; p) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 121, SEQ ID NO: 122 and SEQ ID NO: 123, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 124, SEQ ID NO: 125 and SEQ ID NO: 126; q) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 129, SEQ ID NO: 130 and SEQ ID NO: 131 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 132, SEQ ID NO: 133 and SEQ ID NO: 134; r) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 137, SEQ ID NO: 138 and SEQ ID NO: 139 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 140, SEQ ID NO: 141 and SEQ ID NO: 142; s) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 145, SEQ ID NO: 146 and SEQ ID NO: 147, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 148, SEQ ID NO: 149 and SEQ ID NO: 150; t) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 153, SEQ ID NO: 154 and SEQ ID NO: 155, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 156, SEQ ID NO: 157 and SEQ ID NO: 158; u) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 161, SEQ ID NO: 162 and SEQ ID NO: 163, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 164, SEQ ID NO: 165 and SEQ ID NO: 166; v) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 169, SEQ ID NO: 170 and SEQ ID NO: 171 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 172, SEQ ID NO: 173 and SEQ ID NO: 174; w) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 177, SEQ ID NO: 178 and SEQ ID NO: 179, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 180, SEQ ID NO: 181 and SEQ ID NO: 182; x) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 185, SEQ ID NO: 186 and SEQ ID NO: 187, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 188, SEQ ID NO: 189 and SEQ ID NO: 190; y) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 193, SEQ ID NO: 194 and SEQ ID NO: 195, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 196, SEQ ID NO: 197 and SEQ ID NO: 198; z) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 201, SEQ ID NO: 202 and SEQ ID NO: 203, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 204, SEQ ID NO: 205 and SEQ ID NO: 206; aa) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 209, SEQ ID NO: 210 and SEQ ID NO: 211 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 212, SEQ ID NO: 213 and SEQ ID NO: 214; bb) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 217, SEQ ID NO: 218 and SEQ ID NO: 219 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 220, SEQ ID NO: 221 and SEQ ID NO: 222; cc) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 225, SEQ ID NO: 226 and SEQ ID NO: 227 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 228, SEQ ID NO: 229 and SEQ ID NO: 230; dd) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 233, SEQ ID NO: 234 and SEQ ID NO: 235 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 236, SEQ ID NO: 237 and SEQ ID NO: 238; ee) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 241, SEQ ID NO: 242 and SEQ ID NO: 243 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 244, SEQ ID NO: 245 and SEQ ID NO: 246; ff) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 249, SEQ ID NO: 250 and SEQ ID NO: 251 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 252, SEQ ID NO: 253 and SEQ ID NO: 254; gg) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 257, SEQ ID NO: 258 and SEQ ID NO: 259 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 260, SEQ ID NO: 261 and SEQ ID NO: 262; hh) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 265, SEQ ID NO: 266 and SEQ ID NO: 267 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 268, SEQ ID NO: 269 and SEQ ID NO: 270; ii) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 273, SEQ ID NO: 274 and SEQ ID NO: 275, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 276, SEQ ID NO: 277 and SEQ ID NO: 278; jj) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 281, SEQ ID NO: 282 and SEQ ID NO: 283 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 284, SEQ ID NO: 285 and SEQ ID NO: 286; kk) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 289, SEQ ID NO: 290 and SEQ ID NO: 291 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 292, SEQ ID NO: 293 and SEQ ID NO: 294; ll) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 297, SEQ ID NO: 298 and SEQ ID NO: 299 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 300, SEQ ID NO: 301 and SEQ ID NO: 302; mm) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 305, SEQ ID NO: 306 and SEQ ID NO: 307 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 308, SEQ ID NO: 309 and SEQ ID NO: 310; nn) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 313, SEQ ID NO: 314 and SEQ ID NO: 315, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 316, SEQ ID NO: 317 and SEQ ID NO: 318; oo) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 321, SEQ ID NO: 322 and SEQ ID NO: 323 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 324, SEQ ID NO: 325 and SEQ ID NO: 326; pp) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 329, SEQ ID NO: 330 and SEQ ID NO: 331 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 332, SEQ ID NO: 333 and SEQ ID NO: 334; qq) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 337, SEQ ID NO: 338 and SEQ ID NO: 339 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 340, SEQ ID NO: 341 and SEQ ID NO: 342; or rr) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:9, SEQ ID NO:374 and SEQ ID NO:375 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:376, SEQ ID NO:13 and SEQ ID NO:14; or ss) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 41, SEQ ID NO: 42 and SEQ ID NO: 43, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 377, SEQ ID NO: 45 and SEQ ID NO: 46. Includes.

[0012] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:23, SEQ ID NO:31, SEQ ID NO:39, SEQ ID NO:47, SEQ ID NO:55, SEQ ID NO:63, SEQ ID NO:71, SEQ ID NO:79, SEQ ID NO:87, SEQ ID NO:95, SEQ ID NO:103, SEQ ID NO:111, SEQ ID NO:119, SEQ ID NO:127, SEQ ID NO:135, SEQ ID NO:143, SEQ ID NO:151, SEQ ID NO:159, SEQ ID NO:167, SEQ ID NO:175, SEQ ID NO:183, SEQ ID NO:191, SEQ ID NO:199, SEQ ID NO:207, SEQ ID NO:215, SEQ ID NO:22 3, SEQ ID NO:231, SEQ ID NO:239, SEQ ID NO:247, SEQ ID NO:255, SEQ ID NO:263, SEQ ID NO:271, SEQ ID NO:279, SEQ ID NO:287, SEQ ID NO:295, SEQ ID NO:303, SEQ ID NO:311, SEQ ID NO:319, SEQ ID NO:327, SEQ ID NO:335, SEQ ID NO:343, SEQ ID NO:347, and SEQ ID NO:349, and homologous sequences having at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) sequence identity thereto.

[0013] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are selected from the group consisting of SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:24, SEQ ID NO:32, SEQ ID NO:40, SEQ ID NO:48, SEQ ID NO:56, SEQ ID NO:64, SEQ ID NO:72, SEQ ID NO:80, SEQ ID NO:88, SEQ ID NO:96, SEQ ID NO:104, SEQ ID NO:112, SEQ ID NO:120, SEQ ID NO:128, SEQ ID NO:136, SEQ ID NO:144, SEQ ID NO:152, SEQ ID NO:160, SEQ ID NO:168, SEQ ID NO:1756, SEQ ID NO:184, SEQ ID NO:192, SEQ ID NO:200, SEQ ID NO:208, SEQ ID NO:216, SEQ ID NO:220, SEQ ID NO:222, SEQ ID NO:224, SEQ ID NO:226, SEQ ID NO:228, SEQ ID NO:228, SEQ ID NO:230, SEQ ID NO:232, SEQ ID NO:234, SEQ ID NO:236, SEQ ID NO:238, SEQ ID NO:238, SEQ ID NO:238, SEQ ID NO:239, SEQ ID NO:240, SEQ ID NO:242, SEQ ID NO:244, SEQ ID NO:246, SEQ ID NO:248, SEQ ID NO:246, SEQ ID NO:248, SEQ ID NO:248, SEQ ID NO:249, SEQ ID NO:250, SEQ ID NO:252, SEQ ID NO:254, SEQ ID NO:256, SEQ ID NO:258, SEQ ID NO:2 24, SEQ ID NO:232, SEQ ID NO:240, SEQ ID NO:248, SEQ ID NO:256, SEQ ID NO:264, SEQ ID NO:272, SEQ ID NO:280, SEQ ID NO:288, SEQ ID NO:296, SEQ ID NO:304, SEQ ID NO:312, SEQ ID NO:320, SEQ ID NO:328, SEQ ID NO:336, SEQ ID NO:344, SEQ ID NO:348, and SEQ ID NO:350, and homologous sequences having at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) sequence identity thereto.

[0014] In some embodiments, the antibody or antigen-binding fragment thereof provided herein comprises: a) a heavy chain variable region comprising SEQ ID NO:7 and a light chain variable region comprising SEQ ID NO:8; b) a heavy chain variable region comprising SEQ ID NO: 15 and a light chain variable region comprising SEQ ID NO: 16; c) a heavy chain variable region comprising SEQ ID NO:23 and a light chain variable region comprising SEQ ID NO:24; d) a heavy chain variable region comprising SEQ ID NO:31 and a light chain variable region comprising SEQ ID NO:32; e) a heavy chain variable region comprising SEQ ID NO: 39 and a light chain variable region comprising SEQ ID NO: 40; f) a heavy chain variable region comprising SEQ ID NO: 47 and a light chain variable region comprising SEQ ID NO: 48; g) a heavy chain variable region comprising SEQ ID NO: 55 and a light chain variable region comprising SEQ ID NO: 56; h) a heavy chain variable region comprising SEQ ID NO: 63 and a light chain variable region comprising SEQ ID NO: 64; i) a heavy chain variable region comprising SEQ ID NO: 71 and a light chain variable region comprising SEQ ID NO: 72; j) a heavy chain variable region comprising SEQ ID NO: 79 and a light chain variable region comprising SEQ ID NO: 80; k) a heavy chain variable region comprising SEQ ID NO: 87 and a light chain variable region comprising SEQ ID NO: 88; l) a heavy chain variable region comprising SEQ ID NO: 95 and a light chain variable region comprising SEQ ID NO: 96; m) a heavy chain variable region comprising SEQ ID NO: 103 and a light chain variable region comprising SEQ ID NO: 104; n) a heavy chain variable region comprising SEQ ID NO: 111 and a light chain variable region comprising SEQ ID NO: 112; o) a heavy chain variable region comprising SEQ ID NO: 119 and a light chain variable region comprising SEQ ID NO: 120; p) a heavy chain variable region comprising SEQ ID NO: 127 and a light chain variable region comprising SEQ ID NO: 128; q) a heavy chain variable region comprising SEQ ID NO: 135 and a light chain variable region comprising SEQ ID NO: 136; r) a heavy chain variable region comprising SEQ ID NO: 143 and a light chain variable region comprising SEQ ID NO: 144; s) a heavy chain variable region comprising SEQ ID NO: 151 and a light chain variable region comprising SEQ ID NO: 152; t) a heavy chain variable region comprising SEQ ID NO: 159 and a light chain variable region comprising SEQ ID NO: 160; u) a heavy chain variable region comprising SEQ ID NO: 167 and a light chain variable region comprising SEQ ID NO: 168; v) a heavy chain variable region comprising SEQ ID NO: 175 and a light chain variable region comprising SEQ ID NO: 176; w) a heavy chain variable region comprising SEQ ID NO: 183 and a light chain variable region comprising SEQ ID NO: 184; x) a heavy chain variable region comprising SEQ ID NO: 191 and a light chain variable region comprising SEQ ID NO: 192; y) a heavy chain variable region comprising SEQ ID NO: 199 and a light chain variable region comprising SEQ ID NO: 200; z) a heavy chain variable region comprising SEQ ID NO: 207 and a light chain variable region comprising SEQ ID NO: 208; aa) a heavy chain variable region comprising SEQ ID NO: 215 and a light chain variable region comprising SEQ ID NO: 216; bb) a heavy chain variable region comprising SEQ ID NO: 223 and a light chain variable region comprising SEQ ID NO: 224; cc) a heavy chain variable region comprising SEQ ID NO: 231 and a light chain variable region comprising SEQ ID NO: 232; dd) a heavy chain variable region comprising SEQ ID NO: 239 and a light chain variable region comprising SEQ ID NO: 240; ee) a heavy chain variable region comprising SEQ ID NO: 247 and a light chain variable region comprising SEQ ID NO: 248; ff) a heavy chain variable region comprising SEQ ID NO: 255 and a light chain variable region comprising SEQ ID NO: 256; gg) a heavy chain variable region comprising SEQ ID NO: 263 and a light chain variable region comprising SEQ ID NO: 264; hh) a heavy chain variable region comprising SEQ ID NO: 271 and a light chain variable region comprising SEQ ID NO: 272; ii) a heavy chain variable region comprising SEQ ID NO: 279 and a light chain variable region comprising SEQ ID NO: 280; jj) a heavy chain variable region comprising SEQ ID NO: 287 and a light chain variable region comprising SEQ ID NO: 288; kk) a heavy chain variable region comprising SEQ ID NO: 295 and a light chain variable region comprising SEQ ID NO: 296; ll) a heavy chain variable region comprising SEQ ID NO: 303 and a light chain variable region comprising SEQ ID NO: 304; mm) a heavy chain variable region comprising SEQ ID NO: 311 and a light chain variable region comprising SEQ ID NO: 312; nn) a heavy chain variable region comprising SEQ ID NO: 319 and a light chain variable region comprising SEQ ID NO: 320; oo) a heavy chain variable region comprising SEQ ID NO: 327 and a light chain variable region comprising SEQ ID NO: 328; pp) a heavy chain variable region comprising SEQ ID NO: 335 and a light chain variable region comprising SEQ ID NO: 336; qq) a heavy chain variable region comprising SEQ ID NO: 343 and a light chain variable region comprising SEQ ID NO: 344; rr) a heavy chain variable region comprising SEQ ID NO: 347 and a light chain variable region comprising SEQ ID NO: 348; or ss) a heavy chain variable region comprising SEQ ID NO: 349 and a light chain variable region comprising SEQ ID NO: 350 Includes.

[0015] In some embodiments, the antibody or antigen-binding fragment thereof is humanized.

[0016] In some embodiments, the antibody or antigen-binding fragment thereof comprises SEQ ID NO: 378 (EVQLVESGGGLXQPGXSLRLSCXTSGFTLSDYYMSWVRQXPGKGLEWVXFMRNKANXYTTEYSASVRGRFTISRDTSKSXIYLQMNSLXXEDTAVYYCVRDRXGRPFAYWGQGTLVTVSS), wherein X at position i (i=12, 16, 23, 40, 49, 57, 80, 89, 90, and 103) of SEQ ID NO: 378 is Hi It is called X H12 is V or I, and XH 16 is G or R, and X H23 is A or T, and X H40 is A or P, and X H49 is G or S, and X H57 is A or G, and X H80 is I or T, and X H89 is R or K, and X H90 is A or T, and X H103 is a heavy chain variable region, wherein the heavy chain variable region is D or E, and SEQ ID NO: 379 (DIXMTQSPXSLXXXXGXXXXIXCKSSQSLLNXINQKNFLTWYXQKPGXXPXLLIYWASTRESGVPXRFSGSGSGTDFTLXISXXXXEDLXXYYCQNDYTYPLTFGQGTKLEIK), wherein X at position i of SEQ ID NO: 379 (i=3, 9, 12, 13, 14, 15, 17, 18, 19, 20, 22, 32, 43, 48, 49, 51, 66, 80, 83, 84, 85, 86, 90, and 91) is X Li It is called X L3 is V or Q, and X L9 is D, L or S, and X L12 is A, S or P, and X L13 is A or V, and X L14 is S or T, and X L15 is L, V or P, and X L17 is D or E, and X L18 is R or P, and X L19 is A or V, and X L20is S or T, and X L22 is N, T or S, and X L32 is A or S, and X L43 is Q or L, and X L48 is Q or K, and X L49 is A, P or S, and X L51 is K or Q, and X L66 is S or D, and X L80 is K or T, and X L83 is R or S, and X L84 is L or V, and X L85 is Q or E, and X L86 is A or P, and X L90 is A or G, and X L91 comprises a light chain variable region, which is T or V.

[0017] In some embodiments, the antibody or antigen-binding fragment thereof comprises SEQ ID NO: 380 (QVQLQESGPGLVKPSXTLSLTCXVXGYSITSDYAWNWIRQXPGKGLEWIGYISHSGSTSYNPSLKSRVTISRDTSKNQFSLKLSSVTAADTAVYYCARSLGRRWYFDVWGQGTTVTVSS), wherein X at position i (i=16, 23, 25, and 41) of SEQ ID NO: 380 is Hi It is called X H16 is E or Q, and X H23 is A or T, and X H25 is S or Y, and X H41 is H or P, and SEQ ID NO: 381 (DIXMTQSPXSLXXXXGXXXXIXCKSSQSLLXSSTQKNYLAWYXQKPGXXPXLLIYFASTRDSGVPXRFSGSGSGTDFTLXISXXXXEDLXXYFCQQHYIIPFTFGQGTKLEIK), wherein X at position i of SEQ ID NO: 381 (i=3, 9, 12, 13, 14, 15, 17, 18, 19, 20, 22, 31, 43, 48, 49, 51, 66, 80, 83, 84, 85, 86, 90, and 91) is X Li It is called X L3 is V or Q, and XL9 is D, L or S, and X L12 is A, S or P, and X L13 is A or V, and X L14 is S or T, and X L15 is L, V or P, and X L17 is D or E, and X L18 is R or P, and X L19 is A or V, and X L20 is S or T, and X L22 is N, T or S, and X L31 is N or Q, and X L43 is Q or L, and X L48 is Q or K, and X L49 is A, P or S, and X L51 is K or Q, and X L66 is S or D, and X L80 is K or T, and X L83 is R or S, and X L84 is L or V, and X L85 is Q or E, and X L86 is A or P, and X L90 is A or G, and X L91 comprises a light chain variable region, which is T or V.

[0018] In some embodiments, the antibody or antigen-binding fragment thereof comprises: (i) a heavy chain variable region comprising one, two or three CDR sequences as set forth in SEQ ID NO: 9, SEQ ID NO: 10 or 374 (MRNKANAYTT) and SEQ ID NO: 11 or 375 (VRDREGRPFAY), respectively, and a kappa light chain variable region comprising one, two or three CDR sequences as set forth in SEQ ID NO: 12 or 376 (QSLLNAINQKNF), SEQ ID NO: 13 and SEQ ID NO: 14, respectively; or (ii) a heavy chain variable region comprising one, two or three CDR sequences as set forth as SEQ ID NO:41, SEQ ID NO:42 and SEQ ID NO:43, respectively, and a kappa light chain variable region comprising one, two or three CDR sequences as set forth as SEQ ID NO:44 or 377 (QSLLQSSTQKNY), SEQ ID NO:45 and SEQ ID NO:46, respectively.

[0019] In some embodiments, the antibody or antigen-binding fragment thereof comprises a heavy chain variable region comprising a sequence selected from SEQ ID NOs: 351, 353, 355, 357, 358, 360, 362, 364, 365, 367, and 370, and a light chain variable region comprising a sequence selected from SEQ ID NOs: 352, 354, 356, 359, 361, 363, 366, 368, 369, 371, 372, and 373.

[0020] In some embodiments, the antibody or antigen-binding fragment thereof provided herein comprises: a) a heavy chain variable region comprising SEQ ID NO: 351 and a light chain variable region comprising SEQ ID NO: 352; b) a heavy chain variable region comprising SEQ ID NO: 353 and a light chain variable region comprising SEQ ID NO: 354; c) a heavy chain variable region comprising SEQ ID NO: 355 and a light chain variable region comprising SEQ ID NO: 352; d) a heavy chain variable region comprising SEQ ID NO: 355 and a light chain variable region comprising SEQ ID NO: 356; e) a heavy chain variable region comprising SEQ ID NO: 357 and a light chain variable region comprising SEQ ID NO: 352; f) a heavy chain variable region comprising SEQ ID NO: 357 and a light chain variable region comprising SEQ ID NO: 354; g) a heavy chain variable region comprising SEQ ID NO: 358 and a light chain variable region comprising SEQ ID NO: 359; h) a heavy chain variable region comprising SEQ ID NO: 360 and a light chain variable region comprising SEQ ID NO: 361; i) a heavy chain variable region comprising SEQ ID NO: 362 and a light chain variable region comprising SEQ ID NO: 359; j) a heavy chain variable region comprising SEQ ID NO: 362 and a light chain variable region comprising SEQ ID NO: 363; k) a heavy chain variable region comprising SEQ ID NO: 364 and a light chain variable region comprising SEQ ID NO: 359; l) a heavy chain variable region comprising SEQ ID NO: 364 and a light chain variable region comprising SEQ ID NO: 361; m) a heavy chain variable region comprising SEQ ID NO: 365 and a light chain variable region comprising SEQ ID NO: 366; n) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 368; o) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 369; p) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 366; q) a heavy chain variable region comprising SEQ ID NO: 370 and a light chain variable region comprising SEQ ID NO: 369; r) a heavy chain variable region comprising SEQ ID NO: 370 and a light chain variable region comprising SEQ ID NO: 366; s) a heavy chain variable region comprising SEQ ID NO: 365 and a light chain variable region comprising SEQ ID NO: 371; t) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 372; u) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 373; v) a heavy chain variable region comprising SEQ ID NO: 367 and a light chain variable region comprising SEQ ID NO: 371; w) a heavy chain variable region comprising SEQ ID NO: 370 and a light chain variable region comprising SEQ ID NO: 373; or x) a heavy chain variable region comprising SEQ ID NO: 370 and a light chain variable region comprising SEQ ID NO: 371 Includes.

[0021] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise one or more amino acid residue substitutions or modifications, but retain specific binding affinity for human CD276.

[0022] In some embodiments the substitutions are in one or more of the CDR sequences and / or in one or more of the VH or VL sequences but not in any of the CDR sequences.

[0023] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein further comprise an immunoglobulin constant region, optionally a human Ig constant region, or optionally a human IgG constant region.

[0024] In some embodiments, the constant region comprises a human IgG1, IgG2, IgG3, or IgG4 constant region.

[0025] In some embodiments, the antibodies or antigen-binding fragments thereof provided herein are chimeric or humanized.

[0026] In some embodiments, the antibody or antigen-binding fragment thereof provided herein is a Fab, Fab', F(ab')2, Fd, Fv fragment, disulfide stabilized Fv fragment (dsFv), (dsFv)2, single chain antibody molecule (scFv), camelized single domain antibody, nanobody, domain antibody and bivalent domain antibody.

[0027] In some embodiments, the antibody or antigen-binding fragment is linked to one or more conjugates. In some embodiments, the conjugates are covalently attached, either directly or via a linker.

[0028] In some embodiments, the conjugate comprises a clearance modifier, a chemotherapeutic agent, a toxin, a radioisotope, a lanthanide, a luminescent label, a fluorescent label, an enzyme substrate label, a DNA alkylating agent, a topoisomerase inhibitor, a tubulin binding agent or other anti-cancer drug.

[0029] In some embodiments, the antibody or antigen-binding fragment is capable of specifically binding to CD276. In some embodiments, the CD276 is of human origin. In some embodiments, the CD276 is recombinant CD276 or CD276 expressed on the cell surface.

[0030] In one aspect, the disclosure provides an antibody or antigen-binding fragment thereof that competes with an antibody or antigen-binding fragment thereof provided herein for the same epitope.

[0031] In one aspect, the disclosure provides a pharmaceutical composition comprising an antibody or antigen-binding fragment thereof provided herein and a pharma- ceutical acceptable carrier.

[0032] In some embodiments, the pharmaceutical compositions provided herein further comprise a second therapeutic agent.

[0033] In some embodiments, the second therapeutic agent is an antagonist to one or more immunosuppressive molecules.

[0034] In some embodiments, the second therapeutic agent is a PD-L1 antagonist.

[0035] In some embodiments, the PD-L1 antagonist is a PD-L1 antibody or antigen-binding fragment thereof.

[0036] In one aspect, the disclosure provides an isolated polynucleotide encoding an antibody or antigen-binding fragment thereof provided herein.

[0037] In one aspect, the disclosure provides a vector comprising an isolated polynucleotide provided herein.

[0038] In one aspect, the disclosure provides a host cell comprising a vector provided herein.

[0039] In one aspect, the disclosure provides a method of expressing an antibody or antigen-binding fragment thereof provided herein, the method comprising culturing a host cell provided herein under conditions in which a vector provided herein is expressed.

[0040] In one aspect, the disclosure provides a method of treating a disease or condition in a subject that would benefit from modulation of CD276 activity, the method comprising administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein, or a pharmaceutical composition provided herein.

[0041] In some embodiments, the disease or condition is a CD276-associated disease or condition.

[0042] In some embodiments, the disease or condition is cancer, an adaptive immune disease, an autoimmune disease, an inflammatory disease, or an infectious disease.

[0043] In some embodiments, the cancer is an adrenal gland tumor, AIDS-related cancer, alveolar soft part sarcoma, astrocytic tumor, bladder cancer, bone cancer, brain and spinal cord cancer, metastatic brain tumor, breast cancer, carotid globe tumor, cervical cancer, chondrosarcoma, chordoma, chromophobe renal carcinoma, clear cell carcinoma, colon cancer, colorectal cancer, cutaneous benign fibrous histiocytoma, desmoplastic small round cell tumor, ependymoma, Ewing's tumor, extraskeletal myxoid chondrosarcoma, fibrogenesis imperfecta ossium, fibrous dysplasia, gallbladder or bile duct cancer, gastric cancer, cancer, gestational trophoblastic disease, germ cell tumors, head and neck cancer, hepatocellular carcinoma, pancreatic islet tumors, Kaposi's sarcoma, kidney cancer, leukemia, lipoma / benign lipomatous tumors, liposarcoma / malignant lipomatous tumors, liver cancer, lymphoma, lung cancer, medulloblastoma, melanoma, meningioma, multiple endocrine neoplasia, multiple myeloma, myelodysplastic syndrome, neuroblastoma, neuroendocrine tumors, ovarian cancer, pancreatic cancer, papillary thyroid carcinoma, parathyroid tumors, childhood cancer, peripheral nerve sheath tumors, pheochromocytoma, pituitary tumors, prostate cancer, posterior uveal melanoma, rare blood disorders, metastatic kidney cancer, rhabdomyosarcoma-like tumors, rhabdomyosarcoma, sarcoma, skin cancer, soft tissue sarcoma, squamous cell carcinoma, stomach cancer cancer), synovial sarcoma, testicular cancer, thymic carcinoma, thymoma, thyroid metastatic cancer and uterine cancer, optionally, the cancer is chemotherapy resistant.

[0044] In some embodiments, the disease or condition is a B-cell lymphoma, e.g., a hematological cancer selected from Hodgkin's lymphoma, non-Hodgkin's lymphoma (NHL), acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), multiple myeloma (MM), diffuse large B-cell lymphoma (DLBCL), marginal zone B-cell lymphoma (MZL), mantle cell lymphoma (MCL), Richter's syndrome, Burkitt's lymphoma, or follicular lymphoma.

[0045] In some embodiments, the subject is a human.

[0046] In some embodiments, the methods provided herein include administering to a subject a therapeutically effective amount of one or more therapeutic agents, in some embodiments, the therapeutic agents are chemotherapeutic agents, radiotherapeutic agents, hormonal therapeutic agents, toxins, or immunotherapeutic agents.

[0047] In some embodiments, the second therapeutic agent is a PD-L1 antagonist.

[0048] In some embodiments, the PD-L1 antagonist is an anti-PD-L1 antibody or an antigen-binding fragment thereof.

[0049] In some embodiments, administration is by oral, nasal, intravenous, subcutaneous, sublingual, or intramuscular administration.

[0050] In some embodiments, the method further comprises administration of one or more additional cancer treatments selected from the group consisting of chemotherapy, immunotherapy, radiation therapy, hormone therapy, and surgery.

[0051] In one aspect, the present disclosure provides a method of modulating CD276 activity in a cell expressing CD276, the method comprising exposing a cell expressing CD276 to an antibody or antigen-binding fragment thereof provided herein.

[0052] In one aspect, the present disclosure provides a method of detecting the presence or amount of CD276 in a sample, the method comprising contacting the sample with an antibody or antigen-binding fragment thereof provided herein and determining the presence or amount of CD276 in the sample.

[0053] In one aspect, the present disclosure provides a method of diagnosing a CD276-related disease or condition in a subject, the method comprising: a) obtaining a sample from the subject; b) contacting the sample obtained from the subject with an antibody or antigen-binding fragment thereof provided herein; c) determining the presence or amount of CD276 in the sample; and d) correlating the presence or amount of CD276 with the presence or status of a CD276-related disease or condition in the subject.

[0054] In one aspect, the disclosure provides use of an antibody, or antigen-binding fragment thereof, provided herein in the manufacture of a medicament for treating a CD276-related disease or condition in a subject.

[0055] In some embodiments, the medicament further comprises a second therapeutic agent, hi some embodiments, the second therapeutic agent is a chemotherapeutic agent, a radiation therapeutic agent, a hormone therapeutic agent, a toxin, or an immunotherapeutic agent.

[0056] In some embodiments, the second therapeutic agent is a PD-L1 antagonist, hi some embodiments, the PD-L1 antagonist is an anti-PD-L1 antibody or antigen-binding fragment thereof.

[0057] In one aspect, the disclosure provides use of an antibody, or antigen-binding fragment thereof, provided herein in the manufacture of a diagnostic reagent for diagnosing a CD276-related disease or condition.

[0058] In one aspect, the disclosure provides a kit comprising an antibody or antigen-binding fragment thereof provided herein useful in detecting CD276, optionally recombinant CD276, cell surface expressed CD276, or cells expressing CD276.

[0059] In one aspect, the present disclosure provides a chimeric antigen receptor (CAR) comprising an antigen binding domain, a transmembrane domain, a costimulatory signaling region and a TCR signaling domain, wherein the antigen binding domain specifically binds to CD276 and comprises an antigen binding fragment provided herein. In some embodiments, the antigen binding fragment is a Fab or scFv.

[0060] In some embodiments, the CARs provided herein are bispecific.

[0061] In some embodiments, the CAR is capable of further specifically binding to a second antigen other than CD276 or a second epitope on CD276. In some embodiments, the second antigen is a tumor antigen.

[0062] In some embodiments, the TCR signaling domain is selected from the group consisting of the intracellular signal region sequences of CD3ζ, FccRIγ, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR, or combinations thereof.

[0063] In some embodiments, the transmembrane region comprises the transmembrane region of CD3, CD4, CD8, or CD28.

[0064] In one aspect, the present disclosure provides a nucleic acid sequence encoding a chimeric antigen receptor (CAR) provided herein. In one aspect, the present disclosure provides a cell comprising a nucleic acid sequence provided herein.

[0065] In one aspect, the present disclosure provides a cell genetically modified to express a CAR provided herein.

[0066] In some embodiments, the cell is an immune cell, optionally the immune cell is a T lymphocyte, a NK cell, a monocyte, a macrophage, or a NKT lymphocyte.

[0067] In one aspect, the disclosure provides a vector comprising a nucleic acid sequence provided herein.

[0068] In one aspect, the disclosure provides a method for stimulating a T cell-mediated immune response in a mammal against a cell or tissue expressing CD276, the method comprising administering to the mammal an effective amount of a cell genetically modified to express a CAR provided herein.

[0069] In one aspect, the disclosure provides a method of treating a mammal having a CD276-associated disease or condition, comprising administering to the mammal an effective amount of a cell provided herein, thereby treating the mammal. In some embodiments, the cell is an autologous T cell.

[0070] In some embodiments, the CD276-associated disease or condition is cancer.

[0071] In some embodiments, the mammal is a human subject.

[0072] In one aspect, the disclosure provides for the use of a cell genetically modified to express a CAR provided herein in the manufacture of a medicament for stimulating a T cell-mediated immune response against a cell or tissue expressing CD276 in a mammal.

[0073] In one aspect, the disclosure provides for the use of a cell provided herein in the manufacture of a medicament for treating a mammal having a CD276-associated disease or condition.

[0074] The drawings are for illustration purposes only and not for limitation. [Brief description of the drawings]

[0075] [Figure 1] FIG. 1 shows the binding affinity of anti-CD276 antibodies provided herein to SKOV3 cells as measured by FAC analysis. [Diagram 2] 2A-2E show the binding of 6-D8-E7-A11 to several cancer cell lines expressing B7H3, as measured by FACS analysis. [Diagram 3] 3A-3C show the ADCC effect of anti-CD276 antibodies provided herein on SKOV3 cells. [Figure 4] FIG. 4A and FIG. 4B show the CDC effect of anti-CD276 antibodies provided herein on CHO-S-hCD276 cells. [Figure 5-1] 5A-5C show the indirect ADC cytotoxic effect of anti-CD276 antibodies provided herein on SKOV3 cells. [Figure 5-2] Figures 5D and 5E show the indirect ADC cytotoxic effect of anti-CD276 antibodies provided herein on SKOV3 cells. [Figure 6] FIG. 6 shows the in vivo efficacy of anti-CD276 antibodies provided herein in inhibiting tumor growth in a mouse model inoculated with MC-38-hCD276 (B7H3) tumor cells. [Figure 7] FIG. 7 shows the effect on tumor growth in the subcutaneous calu-6 model in BALB / c nude mice (mean±sem). [Figure 8] FIG. 8 shows IL2 release upon T cell activation in an MLR assay. [Figure 9] FIG. 9 shows IFNγ release upon T cell activation in an MLR assay. [Figure 10] FIG. 10 shows the binding affinity of humanized antibodies derived from 30-C7-C11-D4 to SKOV3. [Figure 11]FIG. 11 shows the binding affinity of humanized antibodies derived from 10-G6-C4-B2 to SKOV3. [Figure 12] FIG. 12 shows the effect on tumor growth in the subcutaneous Calu-6 model in Balb / c nude mice (mean±SEM). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0076] The following description of the present disclosure is intended to merely illustrate various embodiments of the present disclosure. As such, the specific modifications discussed should not be interpreted as limitations on the scope of the present disclosure. It is clear to those skilled in the art that various equivalents, variations and modifications can be made without departing from the scope of the present disclosure, and it is understood that such equivalent embodiments should be included in this specification. All references cited in this specification, including publications, patents and patent applications, are incorporated herein by reference in their entirety.

[0077] definition The term "antibody" as used herein includes any immunoglobulin, monoclonal, polyclonal, multivalent, bispecific or univalent antibody that binds to a specific antigen. A naturally occurring, intact antibody contains two heavy (H) chains and two light (L) chains. Mammalian heavy chains are classified as α, δ, ε, γ and μ, and each heavy chain contains a variable region (V H ) and a first, second, and third constant regions (C H1 , C H2 , C H3 ), mammalian light chains are classified as either λ or κ, and each light chain consists of a variable region (V L) and a constant region. Antibodies have a "Y" shape, with the stem of the Y consisting of the second and third constant regions of two heavy chains bound together via disulfide bonds. Each arm of the Y contains the variable region and the first constant region of a single heavy chain bound to the variable and constant region of a single light chain. The variable regions of the light and heavy chains are involved in antigen binding. The variable regions in both chains generally contain three highly variable loops called complementarity determining regions (CDRs) (light chain CDRs including LCDR1, LCDR2 and LCDR3, heavy chain CDRs including HCDR1, HCDR2 and HCDR3). The CDR boundaries of the antibodies and antigen binding domains disclosed herein may be determined according to the Kabat, IMGT, AbM, Chothia or Al-Lazikani convention (Al-Lazikani, B., Chothia, C., Lesk, A.M., J. Mol. Biol., 273(4), 927(1997); Chothia, C. et al., J Mol Biol. Dec 5; 186(3):651-63(1985); Chothia, C. and Lesk, A.M., J. Mol. Biol., 196, 901(1987); N.R. Whitelegg et al, Protein Engineering, v13(12), 819-824(2000); Chothia, C. et al., Nature. Dec 21-28; 342(6252):877-83(1989); Kabat E.A. et al., National Institutes of Health, Bethesda, Md. (1991); Marie-Paule Lefranc et al, Developmental and Comparative Immunology, 27:55-77 (2003); Marie-Paule Lefranc et al, Immunome Research, 1(3), (2005); Marie-Paule Lefranc, Molecular Biology of B cells (second edition), chapter 26, 481-514, (2015)).The three CDRs are inserted between flanking stretches known as framework regions (FRs), which are more highly conserved than the CDRs and form a scaffold supporting the hypervariable loops. The constant regions of the heavy and light chains are not involved in antigen binding but exhibit various effector functions. Antibodies are assigned to classes based on the amino acid sequence of the constant region of their heavy chains. The five main classes or isotypes of antibodies are IgA, IgD, IgE, IgG and IgM, which are characterized by the presence of α, δ, ε, γ and μ heavy chains, respectively. Some of the major antibody classes are divided into subclasses, such as IgG1 (γ1 heavy chain), IgG2 (γ2 heavy chain), IgG3 (γ3 heavy chain), IgG4 (γ4 heavy chain), IgA1 (α1 heavy chain) or IgA2 (α2 heavy chain).

[0078] The term "antibody molecule" as used herein refers to an antigen-binding protein or polypeptide that comprises at least one antibody fragment (such as a CDR and / or variable region sequence). Antibody molecules include, for example, monoclonal antibodies, antibody fragments or domains, fusion proteins comprising antibody fragments or domains, polypeptide complexes comprising antibody fragments or domains, and the like.

[0079] The term "antigen-binding domain" (e.g., CD276-binding domain) as used herein refers to an antibody fragment formed from a portion of an antibody that includes one or more CDRs or any other antibody fragment that binds to an antigen but does not include an intact native antibody structure. Examples of antigen-binding domains include, but are not limited to, Fab, Fab', F(ab')2, Fv fragments, disulfide-stabilized Fv fragments (dsFv), (dsFv)2, single-chain antibody molecules (scFv), camelized single-domain antibodies, nanobodies, domain antibodies, and bivalent domain antibodies. An antigen-binding domain is capable of binding to the same antigen that the parent antibody binds. In certain embodiments, an antigen-binding domain may comprise one or more CDRs from a particular human antibody grafted onto framework regions from one or more different human antibodies. More detailed formatting of antigen-binding domains is described in Spiess et al., 2015 and Brinkman et al., mAbs, 9(2), pp. 182-212 (2017), which are incorporated by reference in their entireties.

[0080] "Fab," with respect to an antibody, refers to the portion of an antibody that consists of a single light chain (both variable and constant regions) linked by disulfide bonds to the variable region and first constant region of a single heavy chain.

[0081] "Fab'" refers to a Fab fragment that contains part of the hinge region.

[0082] "F(ab')2" refers to a Fab' dimer.

[0083] "Fragment difficult (Fd)" with respect to antibodies refers to the amino terminal half of a heavy chain fragment that can combine with a light chain to form Fab. For example, an Fd fragment can consist of the VH and CH1 domains.

[0084] "Fv" in reference to an antibody refers to the smallest fragment of an antibody that has a complete antigen-binding site. The Fv fragment consists of the variable region of a single light chain linked to the variable region of a single heavy chain. Numerous Fv designs are available, including dsFv, where the association between the two domains is enhanced by an introduced disulfide bond, and scFv, which can be formed using a peptide linker to link the two domains together as a single polypeptide. Fv constructs have also been created that contain the variable domains of the immunoglobulin heavy or light chains associated with the corresponding variable and constant domains of the immunoglobulin heavy or light chains.

[0085] A "single-chain Fv antibody" or "scFv" refers to a genetically engineered antibody consisting of a light chain variable region and a heavy chain variable region connected to each other directly or via a peptide linker sequence (Huston JS et al. Proc Natl Acad Sci USA, 85:5879 (1988)).

[0086] "dsFv" refers to a disulfide-stabilized Fv fragment in which the link between the variable region of a single light chain and the variable region of a single heavy chain is a disulfide bond. In some embodiments, a "(dsFv)2" or "(dsFv-dsFv')" comprises three peptide chains: two Vs linked by a peptide linker (e.g., a long flexible linker) through disulfide bridges, each of which is composed of two Vs. L Two V's attached to the moiety H In some embodiments, dsFv-dsFv' are bispecific in that each disulfide-paired heavy and light chain has a different antigen specificity.

[0087] "Fc" with respect to an antibody refers to the portion of an antibody that consists of the second and third constant regions of a first heavy chain linked to the second and third constant regions of a second heavy chain via disulfide bonds. The Fc portion of an antibody is involved in various effector functions, such as antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC), but does not function in antigen binding.

[0088] "Camelized single domain antibodies", "heavy chain antibodies" or "HCAbs" are antibodies that consist of two V H It refers to antibodies that contain heavy chains and do not contain light chains (Riechmann L. and Muyldermans S., J Immunol Methods. Dec 10; 231(1-2):25-38(1999); Muyldermans S., J Biotechnol. Jun; 74(4):277-302(2001); WO94 / 04678; WO94 / 25591; U.S. Patent No. 6,005,079). Heavy chain antibodies were originally derived from the Camelidae (camels, dromedaries and llamas). Camelized antibodies lack light chains but have a reliable antigen-binding repertoire (Hamers-Casterman C. et al., Nature. Jun 3; 363(6428): 446-8 (1993); Nguyen VK. et al. "Heavy-chain antibodies in Camelidae; a case of evolutionary innovation," Immunogenetics. Apr; 54(1): 39-47 (2002); Nguyen VK. et al. Immunology. May; 109(1): 93-101 (2003)). The variable domain of heavy-chain antibodies (VHH domain) represents the smallest known antigen-binding unit generated by the adaptive immune response (Koch-Nolte F. et al., FASEB J. Nov; 21(13): 3490-8. Epub 2007 Jun 15 (2007)).

[0089] "Nanobody" refers to an antibody fragment consisting of a VHH domain and two constant domains, CH2 and CH3, derived from a heavy chain antibody.

[0090] A "domain antibody" refers to an antibody fragment that contains only the variable region of a heavy chain or the variable region of a light chain. In particular examples, two or more V H The domains are covalently linked with a peptide linker to create a bivalent or multivalent domain antibody. HThe domains may target the same or different antigens.

[0091] The term "chimeric" as used herein refers to an antibody or antigen-binding domain having a portion of a heavy and / or light chain derived from one species and the remainder of the heavy and / or light chain derived from another species. In an illustrative example, a chimeric antibody may contain a constant region derived from a human and a variable region derived from a non-human species, such as a mouse. In some embodiments, the non-human animal is a mammal, such as a mouse, rat, rabbit, goat, sheep, guinea pig, or hamster.

[0092] The term "humanized" as used herein means that an antibody or antigen-binding domain contains CDRs derived from a non-human animal, FR regions derived from a human, and, where applicable, constant regions derived from a human.

[0093] The term "operably linked" or "operably linked" refers to the juxtaposition of two or more biological sequences of interest, with or without spacers or linkers or intervening sequences, in a relationship that allows them to function in their intended manner. When used in reference to a polypeptide, it is intended to mean that the polypeptide sequences are linked in a manner that allows the linked product to have the intended biological function. For example, an antibody variable region can be operably linked to a constant region to provide a stable product with antigen-binding activity. As another example, an antigen-binding domain can be operably linked to another antigen-binding domain via an intervening sequence between them, which may be a spacer or may include a much longer sequence, such as the constant region of an antibody. This term can also be used in reference to polynucleotides. As an example, when a polynucleotide encoding a polypeptide is operably linked to a regulatory sequence (e.g., a promoter, enhancer, silencer sequence, etc.), it is intended to mean that the polynucleotide sequences are linked in a manner that allows regulated expression of the polypeptide from the polynucleotide.

[0094] The terms "fusion" or "fused" when used in reference to amino acid sequences (e.g., peptides, polypeptides, or proteins) refer to the joining of two or more amino acid sequences into a single non-naturally occurring amino acid, for example, by chemical linkage or recombinant means. A fused amino acid sequence can be produced by genetic recombination of two encoding polynucleotide sequences and expressed by a method in which a construct containing the recombinant polynucleotide is introduced into a host cell.

[0095] "Antigen" as used herein refers to a compound, composition, peptide, polypeptide, protein or substance capable of stimulating the production of antibodies or a T-cell response in a cell culture or animal, including compositions (such as those containing cancer-specific proteins) that are added to cell cultures (such as hybridomas) or injected or absorbed into animals. Antigens react with the products of specific humoral or cellular immunity (such as antibodies), including those induced by heterologous antigens.

[0096] The term "CD276 protein" or "B7-H3 protein," as used herein, is intended to encompass any form of CD276, e.g., 1) the native, unprocessed CD276 molecule, a "full-length" CD276 chain or a naturally occurring variant of CD276, including, e.g., a splice variant or an allelic variant; 2) any form of CD276 that results from processing in the cell; or 3) full-length, fragments (e.g., truncated forms, extracellular / transmembrane domains) or modified forms (e.g., mutated forms, glycosylated / PEGylated, His-tagged / immunofluorescence fused forms) of the CD276 subunit produced by recombinant methods.

[0097] The terms "anti-CD276 antibody," "anti-CD276 binding domain," or "CD276 binding domain" refer to an antibody or antigen-binding domain capable of specifically binding to CD276 (e.g., human, monkey, or mouse CD276).

[0098] The terms "specific binding" or "specifically binding," as used herein, refer to a non-random binding reaction between two molecules, such as, for example, between an antibody and an antigen.

[0099] Binding of antibodies to recombinant CD276 or CD276 expressed on the surface of cells was determined by the "half maximal effective concentration" (EC 50 ) value, which refers to the concentration of an antibody at which 50% of its maximal effect (e.g., binding or inhibition, etc.) is observed. 50 Values ​​can be measured by methods known in the art, for example, sandwich assays such as ELISA, Western blot, flow cytometry assays and other binding assays. In certain embodiments, the antibodies and fragments thereof provided herein have an EC of 0.05nM or less, 0.06nM or less, 0.07nM or less, 0.08nM or less, 0.09nM or less, 0.1nM or less, 0.2nM or less, 0.3nM or less, 0.4nM or less, 0.5nM or less, 0.6nM or less, 0.7nM or less, 0.8nM or less, 0.9nM or less, 1nM or less, 1.5nM or less, 2nM or less, 2.5nM or less, 3.5nM or less, 3nM or less, 4nM or less, 4.5nM or less, 5nM or less, 6nM or less, 7nM or less, 8nM or less, 9nM or less, or 10nM or less by flow cytometry. 50 (i.e., 50% binding concentration) to recombinant human CD276.

[0100] The ability to "block binding" or "compete for the same epitope" as used herein refers to the ability of an antibody or antigen-binding domain to inhibit the binding interaction between two molecules (e.g., human CD276 and its binding ligand, e.g., TLT-2) to any detectable degree. In certain embodiments, an antibody or antigen-binding domain that blocks binding between two molecules inhibits the binding interaction between the two molecules by at least 85% or at least 90%. In certain embodiments, the inhibition may be greater than 85% or greater than 90%.

[0101] The term "epitope" as used herein refers to a particular group of atoms or amino acids on an antigen to which an antibody binds. Epitopes can be formed from both contiguous amino acids (also called linear or contiguous epitopes) or non-contiguous amino acids juxtaposed by tertiary folding of a protein (also called configurational or conformational epitopes). Epitopes formed from contiguous amino acids are typically arranged linearly along the primary amino acid residues on a protein, and small segments of contiguous amino acids can be digested out of an antigen bound to a major histocompatibility complex (MHC) molecule or can be retained upon exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost upon treatment with denaturing solvents. An epitope typically contains at least 3, more usually at least 5, about 7 or about 8-10 amino acids in a unique spatial structure. Two antibodies can bind to the same or closely related epitopes within an antigen if they exhibit competitive binding for the antigen. For example, an antibody or antigen-binding domain can be considered to bind to the same / closely related epitope as a reference antibody if it blocks binding of the reference antibody to the antigen by at least 85%, or at least 90%, or at least 95%.

[0102] "Conservative substitution" refers to the substitution of an amino acid residue with a different amino acid residue with a side chain having similar physiochemical properties in terms of amino acid sequence.For example, conservative substitution can be made between amino acid residues with hydrophobic side chains (e.g., Met, Ala, Val, Leu and Ile), between residues with neutral hydrophilic side chains (e.g., Cys, Ser, Thr, Asn and Gln), between residues with acidic side chains (e.g., Asp, Glu), between amino acids with basic side chains (e.g., His, Lys and Arg), or between residues with aromatic side chains (e.g., Trp, Tyr and Phe).As is known in the art, conservative substitution usually does not cause significant changes in the conformational structure of protein, and therefore can retain the biological activity of protein.

[0103] The terms "homolog" and "homologous" as used herein refer to a nucleic acid sequence (or its complementary strand) or amino acid sequence that is interchangeable and has at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) sequence identity to another sequence when optimally aligned.

[0104] "Percent (%) sequence identity" is defined, with respect to an amino acid sequence (or nucleic acid sequence), as the percentage of amino acid (or nucleic acid) residues in a candidate sequence that are identical to the amino acid (or nucleic acid) residues in a reference sequence after aligning the sequences and, if necessary, introducing gaps to achieve the maximum number of identical amino acids (or nucleic acids). Conservative substitutions of amino acid residues may or may not be considered identical residues. Alignment for purposes of determining percent amino acid (or nucleic acid) sequence identity can be accomplished by using publicly available tools such as, for example, BLASTN, BLASTp (available at the US National Center for Biotechnology Information (NCBI) website, see also Altschul SF et al, J. Mol. Biol., 215:403-410 (1990); Stephen F. et al, Nucleic Acids Res., 25:3389-3402 (1997)), ClustalW2 (available at the European Bioinformatics Institute website, see also Higgins D Get al, Methods in Enzymology, 266:383-402 (1996); Larkin MA et al, Bioinformatics (Oxford, England), 23(21):2947-8 (2007)) and ALIGN or Megalign (DNASTAR) software. One skilled in the art may use the default parameters provided by the tool or may customize the parameters as needed for the alignment, such as by selecting a suitable algorithm.

[0105] "Effector function" as used herein refers to the biological activity resulting from the binding of the Fc region of an antibody to its effector, such as the C1 complex, Fc receptor and effector cell (e.g., macrophage). Exemplary effector functions include complement-dependent cytotoxicity (CDC) induced by the interaction of an antibody with C1q on the C1 complex, antibody-dependent cell-mediated cytotoxicity (ADCC) induced by the binding of the Fc region of an antibody to an Fc receptor on an effector cell, and antibody-dependent cellular phagocytosis (ADCP) induced by the binding of the Fc region of an antibody to a phagocytic cell. It is well established that certain glycan structures associated with the conserved biantennary glycan in the Fc-CH2 domain can strongly affect the interaction with FcyR that mediates ADCC and ADCP, as well as the interaction with Clq binding, which is the initial binding event that leads to CDC (see Reusch D, Tejada ML. Fc glycans of therapeutic antibodies as critical quality attributes. Glycobiology 2015;25:1325-34).

[0106] "Treating" or "treatment" of a condition, as used herein, includes preventing or alleviating the condition, slowing the onset or rate of occurrence of the condition, reducing the risk of occurrence of the condition, preventing or delaying the onset of symptoms associated with the condition, reducing or terminating symptoms associated with the condition, causing complete or partial regression of the condition, curing the condition, or some combination thereof.

[0107] The terms "subject" or "individual" or "animal" or "patient" as used herein refer to a human or non-human animal, including a mammal or primate, in need of diagnosis, prognosis, amelioration, prevention and / or treatment of a disease or disorder. Mammalian subjects include humans, monkeys, farm animals, livestock and zoo, sport or pet animals such as dogs, cats, guinea pigs, rabbits, rats, mice, horses, pigs, cows, bears, etc.

[0108] The term "vector" as used herein refers to a vehicle into which a polynucleotide encoding a protein can be operatively inserted to cause expression of the protein. A vector can be used to transform, transduce or transfect a host cell to cause expression of the genetic element it carries in the host cell. Examples of vectors include plasmids, phagemids, cosmids, and artificial chromosomes such as yeast artificial chromosomes (YACs), bacterial artificial chromosomes (BACs) or P1-derived artificial chromosomes (PACs), bacteriophages such as lambda phage or M13 phage, and animal viruses. Categories of animal viruses used as vectors include retroviruses (including lentiviruses), adenoviruses, adeno-associated viruses, herpes viruses (e.g., herpes simplex viruses), pox viruses, baculoviruses, papilloma viruses and papova viruses (e.g., SV40). A vector can contain various elements for controlling expression, including promoter sequences, transcription initiation sequences, enhancer sequences, selectable elements and reporter genes. In addition, a vector can contain an origin of replication. The vector may also contain materials to aid its entry into a cell, including, but not limited to, a viral particle, a liposome, or a protein coating. The vector may be an expression vector or a cloning vector.

[0109] The term "host cell," as used herein, refers to a cell into which an exogenous polynucleotide and / or vector has been introduced.

[0110] "CD276-associated disease or condition," as used herein, refers to any disease or condition caused by, exacerbated by, or otherwise associated with, increased or decreased expression or activity of CD276. In some embodiments, the CD276-associated condition includes an immune-related disorder, such as cancer, an autoimmune disease, an inflammatory disease, or an infectious disease.

[0111] "Cancer," as used herein, refers to any medical condition characterized by malignant cell growth or neoplasia, abnormal proliferation, invasion, or metastasis, and includes both solid tumors and non-solid cancers (hematologic malignancies), such as leukemia. As used herein, a "solid tumor" refers to a solid mass of neoplastic and / or malignant cells. Examples of cancers or tumors include adrenal tumors, AIDS-related cancers, alveolar soft part sarcoma, astrocytic tumors, bladder cancer, bone cancer, brain and spinal cord cancer, metastatic brain tumors, breast cancer, carotid globe tumors, cervical cancer, chondrosarcoma, chordoma, chromophobe renal carcinoma, clear cell carcinoma, colon cancer, colorectal cancer, cutaneous benign fibrous histiocytoma, desmoplastic small round cell tumor, ependymoma, Ewing's tumor, extraskeletal myxoid chondrosarcoma, fibrous ossification imperfecta, fibrous dysplasia, gallbladder or bile duct cancer, gastric cancer, gestational trophoblastic disease, germ cell tumors, head and neck cancer, hepatocellular carcinoma, pancreatic islet tumors, Kaposi's sarcoma, kidney cancer, leukemia, lipoma These include benign lipomatous tumors, liposarcoma / malignant lipomatous tumors, liver cancer, lymphoma, lung cancer, medulloblastoma, melanoma, meningioma, multiple endocrine neoplasia, multiple myeloma, myelodysplastic syndrome, neuroblastoma, neuroendocrine tumors, ovarian cancer, pancreatic cancer, papillary thyroid carcinoma, parathyroid tumor, childhood cancer, peripheral nerve sheath tumor, pheochromocytoma, pituitary tumor, prostate cancer, posterior uveal melanoma, rare blood disorders, metastatic renal cancer, rhabdomyosarcoma-like tumor, rhabdomyosarcoma, sarcoma, skin cancer, soft tissue sarcoma, squamous cell carcinoma, gastric cancer, synovial sarcoma, testicular cancer, thymic carcinoma, thymoma, metastatic thyroid cancer, and uterine cancer.

[0112] In certain embodiments, the hematological malignancies include B-cell lymphoma, optionally Hodgkin's lymphoma, non-Hodgkin's lymphoma (NHL), acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), multiple myeloma (MM), diffuse large B-cell lymphoma (DLBCL), marginal zone B-cell lymphoma (MZL), mantle cell lymphoma (MCL), Richter's syndrome, Burkitt's lymphoma, or follicular lymphoma.

[0113] In certain embodiments, the cancer is selected from gastric cancer, breast cancer, head and neck cancer, pancreatic cancer and colon cancer. In certain embodiments, the cancer is selected from lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma and B-cell lymphoma.

[0114] In certain embodiments, cancer is chemotherapy-resistant.The term "chemoresistant cancer" as used herein refers to the type of cancer that does not respond to the effects of chemotherapy.For example, cancer that responds to chemotherapy or different combinations of chemotherapy suddenly begins to grow, and may be called chemotherapy-resistant cancer.

[0115] The term "pharmaceutical acceptable" indicates that the specified carrier, vehicle, diluent, excipient(s) and / or salt is generally chemically and / or physically compatible with the other ingredients comprising the formulation and physiologically compatible with the recipient thereof.

[0116] Anti-CD276 antibody The present disclosure relates to anti-CD276 antibodies 9-E8-F9-C10, 10-G6-C4-B2, 18-F9-D8-G7, 9-G2-H6-E4, 20-F8-B5-G2, 30-C7-C11-D4, 23-F10-G4-F11, 6-H11-G5-D8, 27-E7-D8-C7, 30-E2-G7-G7, 5-D1-G6-D9, 3- C2-C3-E7, 11-G10-B4-B11, 16-C6-F7-F5, 22-E11-C3-F2, 24-C10-F9-G7, 25-C8-D7-C5, 4- D5-B9-B11, 10-B9-D10-A12, 15-G1-D1-E3, 8-B4-F5-E11, 6-F3-G2-G1, 9-B9-H11-G7, 9-G12 -D6-A11, 13-A8-C4-G1, 15-C8-B5-G7, 28-G2-E6-B10, 3-G7-D8-D3, 14-E7-G9-D4, 20-C5-D 7-D3, 8-C3-E3-F3, 2-A7-B10-A3, 26-D2-D6-B12, 11-C12-F4-F6, 16-G3-D10-C10, 27-F8-E1 Provided herein are anti-CD276 antibodies and antigen-binding fragments thereof that comprise one or more (e.g., 1, 2, 3, 4, 5, or 6) CDR sequences of 0-E11, 7-E1-F8-F6, 25-D3-G4-C6, 13-E4-G9-A4, 20-A2-D10-G8, 3-F2-E7-F9, 6-D8-E7-A11, and 21-B3-B1-H5. In certain embodiments, provided herein are anti-CD276 antibodies and antigen-binding fragments thereof that can specifically bind to CD276. Optionally, CD276 is derived from a human, monkey, or mouse. In certain embodiments, CD276 is recombinant CD276 or CD276 expressed on the cell surface.

[0117] All of the anti-CD276 antibodies and antigen-binding fragments thereof provided herein are mouse monoclonal antibodies. Table 1 shows the CDR sequences of these 43 anti-CD276 antibodies according to the IMGT numbering system. The heavy and light chain variable region sequences are also provided below.

[0118] [Table 1-1] [Table 1-2] [Table 1-3] [Table 1-4]

[0119] 9-E8-F9-C10, 10-G6-C4-B2, 18-F9-D8-G7, 9-G2-H6-E4, 20-F8-B5-G2, 30-C7-C11- D4, 23-F10-G4-F11, 6-H11-G5-D8, 27-E7-D8-C7, 30-E2-G7-G7, 5-D1-G6-D9, 3-C2- C3-E7, 11-G10-B4-B11, 16-C6-F7-F5, 22-E11-C3-F2, 24-C10-F9-G7, 25-C8-D7-C5 , 4-D5-B9-B11, 10-B9-D10-A12, 15-G1-D1-E3, 8-B4-F5-E11, 6-F3-G2-G1, 9-B9-H11 -G7, 9-G12-D6-A11, 13-A8-C4-G1, 15-C8-B5-G7, 28-G2-E6-B10, 3-G7-D8-D3, 14-E 7-G9-D4, 20-C5-D7-D3, 8-C3-E3-F3, 2-A7-B10-A3, 26-D2-D6-B12, 11-C12-F4-F6, The heavy or light chain variable region sequences of the 16-G3-D10-C10, 27-F8-E10-E11, 7-E1-F8-F6, 25-D3-G4-C6, 13-E4-G9-A4, 20-A2-D10-G8, 3-F2-E7-F9, 6-D8-E7-A11 and 21-B3-B1-H5 antibodies are provided in Table 2.

[0120] [Table 2-1] [Table 2-2] [Table 2-3]

Table 2-4

Table 2-5

Table 2-6

Table 2-7

[0121] Although the CDRs are known to be involved in antigen binding, not all of the 6 CDRs are known to be essential or invariant. In other words, the anti-CD276 antibodies 9-E8-F9-C10, 10-G6-C4-B2, 18-F9-D8-G7, 9-G2-H6-E4, 20-F8-B5-G2, 30-C7-C11-D4, 23-F10-G4-F11, 6-H11-G5-D8, 27-E7-D8-C7, 30-E2-G7-G7, 5-D1-G6-D9, 3-C2- C3-E7, 11-G10-B4-B11, 16-C6-F7-F5, 22-E11-C3-F2, 24-C10-F9-G7, 25-C8-D7-C5, 4-D5-B9 -B11, 10-B9-D10-A12, 15-G1-D1-E3, 8-B4-F5-E11, 6-F3-G2-G1, 9-B9-H11-G7, 9-G12-D6-A1 1, 13-A8-C4-G1, 15-C8-B5-G7, 28-G2-E6-B10, 3-G7-D8-D3, 14-E7-G9-D4, 20-C5-D7-D3, 8- C3-E3-F3, 2-A7-B10-A3, 26-D2-D6-B12, 11-C12-F4-F6, 16-G3-D10-C10, 27-F8-E10-E11, 7- It is possible to replace, alter or modify one or more CDRs in E1-F8-F6, 25-D3-G4-C6, 13-E4-G9-A4, 20-A2-D10-G8, 3-F2-E7-F9, 6-D8-E7-A11 and 21-B3-B1-H5 while substantially retaining specific binding affinity for CD276.

[0122] In certain embodiments, the anti-CD276 antibodies and antigen-binding fragments provided herein include anti-CD276 antibodies 9-E8-F9-C10, 10-G6-C4-B2, 18-F9-D8-G7, 9-G2-H6-E4, 20-F8-B5-G2, 30-C7-C11-D4, 23-F10-G4-F11, 6-H11-G5-D8, 2 7-E7-D8-C7, 30-E2-G7-G7, 5-D1-G6-D9, 3-C2-C3-E7, 11-G10-B4-B11, 16-C6-F7-F5, 22- E11-C3-F2, 24-C10-F9-G7, 25-C8-D7-C5, 4-D5-B9-B11, 10-B9-D10-A12, 15-G1-D1-E3, 8- B4-F5-E11, 6-F3-G2-G1, 9-B9-H11-G7, 9-G12-D6-A11, 13-A8-C4-G1, 15-C8-B5-G7, 28-G 2-E6-B10, 3-G7-D8-D3, 14-E7-G9-D4, 20-C5-D7-D3, 8-C3-E3-F3, 2-A7-B10-A3, 26-D2-D6 -B12, 11-C12-F4-F6, 16-G3-D10-C10, 27-F8-E10-E11, 7-E1-F8-F6, 25-D3-G4-C6, 13-E4-G9-A4, 20-A2-D10-G8, 3-F2-E7-F9, 6-D8-E7-A11, and 21-B3-B1-H5. In certain embodiments, the anti-CD276 antibodies and antigen-binding fragments provided herein comprise a heavy chain CDR3 sequence selected from the group consisting of SEQ ID NOs: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227, 235, 243, 251, 259, 267, 275, 283, 291, 299, 307, 315, 323, 331 and 339. The heavy chain CDR3 region is located in the center of the antigen binding site and is therefore believed to make the most contacts with the antigen and provide the most free energy for the affinity of the antibody for the antigen.Moreover, the heavy chain CDR3 is considered to be by far the most diverse CDR of the antigen-binding site in terms of length, amino acid composition and conformation through multiple diversification mechanisms (Tonegawa S. Nature. 302: 575-81). The diversity of the heavy chain CDR3 is sufficient to provide most antibody specificities (Xu JL, Davis MM. Immunity. 13: 37-45) as well as desirable antigen-binding affinities (Schier R, etc. J Mol Biol. 263: 551-67).

[0123] In certain embodiments, the antibodies and / or antigen-binding fragments thereof provided herein comprise suitable framework region (FR) sequences, so long as the antibodies and / or antigen-binding fragments thereof are capable of specifically binding to CD276. The CDR sequences provided in Table 1 are derived from mouse antibodies, but they can be grafted into any suitable FR sequence of any suitable species, e.g., mouse, human, rat, rabbit, among others, using suitable methods known in the art, e.g., recombinant techniques.

[0124] In certain embodiments, the antibody and / or antigen-binding fragment thereof provided herein is PTM-optimized. As used herein, PTM-optimized refers to post-translational modification aimed at avoiding potential aggregation, loss of activity or other risks. Exemplary PTM-optimized antibodies and / or antigen-binding fragments thereof include mVH5-mVL4-10 and mVH-mVL1-30, which are derived from 10-G6-C4-B2 and 30-C7-C11-D4, respectively. The variable region sequences of mVH5-mVL4-10 and mVH-mVL1-30 are shown in Table 3, with all CDR regions underlined.

[0125] [Table 3]

[0126] In certain embodiments, the antibody and / or its antigen-binding fragment provided herein is humanized. Humanized antibody or antigen-binding fragment is desirable for its reduced immunogenicity in humans. Humanized antibody is chimeric in its variable region because non-human CDR sequence is grafted to human or substantially human FR sequence. Humanization of antibody or antigen-binding fragment can be essentially performed by replacing non-human (such as mouse) CDR gene with corresponding human CDR gene in human immunoglobulin gene (see, for example, Jones et al. (1986) Nature 321:522-525; Riechmann et al. (1988) Nature 332:323-327; Verhoeyen et al. (1988) Science 239:1534-1536).

[0127] Methods known in the art can be used to select suitable human heavy and light chain variable domains to achieve this goal. In an illustrative example, a "best-fit" approach can be used, where a non-human (e.g., rodent) antibody variable domain sequence is screened or BLASTed against a database of known human variable domain sequences to identify the closest human sequence to the non-human query sequence and used as a human scaffold for grafting the non-human CDR sequence (see, for example, Sims et al., (1993) J. Immunol. 151:2296; Chothia et al. (1987) J. Mot. Biol. 196:901). Alternatively, frameworks derived from consensus sequences of all human antibodies may be used for grafting non-human CDRs (see, e.g., Carter et al. (1992) Proc. Natl. Acad. Sci. USA, 89:4285; Presta et al. (1993) J. Immunol., 151:2623). In certain embodiments, the humanized antibodies or antigen-binding fragments provided herein are composed of substantially all human sequences, except for the CDR sequences, which are non-human. In some embodiments, the variable region FRs and, if present, the constant region are derived entirely or substantially from human immunoglobulin sequences. The human FR sequences and human constant region sequences, e.g., the FR sequences from one human antibody and the constant region from another human antibody, may be derived from different human immunoglobulin genes.

[0128] Table 4 below shows hVH2-hVL1-10, hVH3-hVL3-10, hVH4-hVL1-10, hVH4-hVL2-10, hVH5-hVL1-1 0, hVH5-hVL3-10, 10-G6-C4-B2_hVH2-VL1_PTM, 10-G6-C4-B2_hVH3-VL3_PTM, 10-G6 -C4-B2_hVH4-VL1_PTM, 10-G6-C4-B2_hVH4-VL2_PTM, 10-G6-C4-B2_hVH5-VL1_PTM, 10-G6-C4-B2_hVH5-VL3_PTM, hVH1-hVL5-30, hVH2-hVL1-30, hVH3-hVL2-30, hVH3-h 1 shows the heavy and light chain variable region amino acid sequences of the humanized antibodies for 10-G6-C4-B2 and 30-C7-C11-D4, designated VL5-30, hVH4-hVL2-30, hVH4-hVL5-30, 30-C7-C11-D4_hVH1-hVL5_PTM, 30-C7-C11-D4_hVH2-hVL1_PTM, 30-C7-C11-D4_hVH3-hVL2_PTM, 30-C7-C11-D4_hVH3-hVL5_PTM, 30-C7-C11-D4_hVH4-hVL2_PTM and 30-C7-C11-D4_hVH4-hVL5_PTM, with all CDR regions underlined.

[0129] [Table 4-1] [Table 4-2] [Table 4-3] [Table 4-4]

[0130] In certain embodiments, the humanized antibody or antigen-binding fragment thereof provided herein is composed of substantially all human sequences, except for the CDR sequences, which are non-human. In some embodiments, the variable region FR, and, if present, the constant region, are derived entirely or substantially from human immunoglobulin sequences. The human FR sequences and the human constant region sequences may be derived from different human immunoglobulin genes, e.g., the FR sequences may be derived from one human antibody and the constant region may be derived from another human antibody. In some embodiments, the humanized antibody or antigen-binding fragment thereof comprises human heavy chain HFR1-4 and / or light chain LFR1-4.

[0131] In some embodiments, the FR region derived from a human may contain the same amino acid sequence as the human immunoglobulin from which it is derived. In some embodiments, one or more amino acid residues of the human FR are replaced with the corresponding residues from the parent non-human antibody. This may be desirable in certain embodiments to generate a humanized antibody or fragment thereof that closely resembles the non-human parent antibody structure in order to optimize binding characteristics (e.g., increase binding affinity). In certain embodiments, the humanized antibody or antigen-binding fragment thereof provided herein contains no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residue substitutions in each of the human FR sequences, or no more than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 amino acid residue substitutions in all FR sequences of the heavy or light chain variable domain. In some embodiments, such amino acid residue changes may be present in only the heavy chain FR region, only the light chain FR region, or in both chains. In certain embodiments, one or more amino acids of the human FR sequence are randomly mutated to increase binding affinity. In certain embodiments, one or more amino acids of the human FR sequences are backmutated to the corresponding amino acid of the parent non-human antibody to increase binding affinity.

[0132] In certain embodiments, the anti-CD276 antibodies and fragments thereof provided herein further comprise an immunoglobulin constant region. In some embodiments, the immunoglobulin constant region comprises a heavy chain and / or a light chain constant region. The heavy chain constant region comprises a CH1, hinge and / or CH2-CH3 region. In certain embodiments, the heavy chain constant region comprises an Fc region. In certain embodiments, the light chain constant region comprises a Cκ or Cλ.

[0133] In some embodiments, the anti-CD276 antibodies and antigen-binding fragments thereof provided herein have an immunoglobulin (Ig) constant region, optionally a human Ig, optionally a human IgG. In some embodiments, the anti-CD276 antibodies and antigen-binding fragments thereof provided herein comprise a human IgG1, IgG2, IgG3, or IgG4 constant region.

[0134] Human IgG isotypes (subclasses of mature gamma globulin class G antibodies; IgG1, IgG2, IgG3 and IgG4) exhibit different abilities to recruit effector functions. For example, ADCC is promoted by IgG1 and IgG3, ADCP is promoted by IgG1, IgG2, IgG3 and IgG4, and CDC is promoted by IgG1 and IgG3. Such isotype-specific involvement of effector functions is based on selectivity for Fc receptors on different immune cells and their ability to bind C1q, thereby activating the assembly of the membrane attack complex (MAC). Among the various isotypes, the relative affinity for Fcγ receptors, including FcγRI, FcγRIIa / b / c and FcγRIIIa / b, is high for IgG1 and IgG3. However, the affinity of Fcγ for IgG2 is rather low, except for the FcγRIIa H131 polymorphism, and IgG4 has only measurable affinity for FcγRI.

[0135] In certain embodiments, the anti-CD276 antibody and antigen-binding fragments provided herein comprise a constant region of human IgG1 isotype, or a constant region of IgG4 or IgG2 isotype with reduced or depleted effector function, which can induce ADCC, CDC or ADCP. Effector function, such as ADCC and CDC, can cause cytotoxicity against cells expressing CD276. Effector function can be evaluated using various assays, such as Fc receptor binding assay, C1q binding assay and cytolysis assay.

[0136] In certain embodiments, the anti-CD276 antibodies and antigen-binding fragments thereof provided herein comprise a constant region of the murine IgG2 isotype capable of inducing ADCC, CDC or ADCP.

[0137] Antibody variants The present disclosure also encompasses various variants of the antibody and / or its antigen-binding fragment provided herein.In certain embodiments, the present disclosure encompasses various kinds of variants of the exemplary antibody provided herein, i.e., the antibody having heavy chain CDR3 sequence selected from the group consisting of SEQ ID NO: 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227, 235, 243, 251, 259, 267, 275, 283, 291, 299, 307, 315, 323, 331, 339, or 375.

[0138] In certain embodiments, the antibody variants comprise one or more modifications or substitutions in one or more CDR sequences as provided in Table 1, one or more FR sequences, heavy or light chain variable region sequences and / or constant regions (e.g., Fc regions) as provided in Table 2. Such variants retain the specific binding affinity of their parent antibody to CD276, but have one or more desirable properties conferred by the modification(s) or substitution(s). For example, the antibody variants may have improved antigen binding affinity, improved glycosylation pattern, reduced risk of glycosylation, reduced deamination, reduced or eliminated effector function(s), improved FcRn receptor binding, increased pharmacokinetic half-life, pH sensitivity and / or suitability for conjugation (e.g., one or more introduced cysteine ​​residues).

[0139] Using methods known in the art, e.g., "alanine scanning mutagenesis," parent antibody sequences may be screened to identify suitable or preferred residues to be modified or substituted (see, e.g., Cunningham and Wells (1989) Science, 244:1081-1085). Briefly, target residues (e.g., charged residues, e.g., Arg, Asp, His, Lys, and Glu) can be identified and replaced with neutral or negatively charged amino acids (e.g., alanine or polyalanine), and the modified antibodies are produced and screened for interesting properties. If substitution of a particular amino acid position demonstrates an interesting functional change, that position can be identified as a promising residue for modification or substitution. The identified promising residues may be further evaluated by substituting different types of residues (e.g., cysteine ​​residues, positively charged residues, etc.).

[0140] Affinity mutants Affinity variants may contain modifications or substitutions in one or more CDR sequences as provided in Table 1, one or more FR sequences, or heavy or light chain variable region sequences as provided in Tables 2, 3, or 4. Affinity variants retain the specific binding affinity of their parent antibody to CD276, or further have improved specific binding affinity for CD276 over the parent antibody. In certain embodiments, at least one (or all) substitutions in the CDR, FR, or variable region sequences comprise conservative substitutions.

[0141] Those skilled in the art will understand that one or more amino acid residues may be substituted in the CDR and FR sequences provided in Table 1, while the resulting antibody or antigen-binding fragment still retains or even has improved binding affinity with CD276. Various methods known in the art can be used to achieve this goal. For example, phage display technology can be used to generate and express a library of antibody mutants (such as Fab or scFv mutants), and then screened for binding affinity with human CD276. For another example, computer software can be used to substantially simulate the binding of an antibody to human CD276, and identify amino acid residues on the antibody that form the binding surface. Such residues may be avoided in substitutions to prevent a reduction in binding affinity, or may be targeted for substitution to provide stronger binding.

[0142] In certain embodiments, the humanized antibody or antigen-binding fragment provided herein comprises one or more amino acid residue substitutions in one or more CDR sequences and / or one or more FR sequences. In certain embodiments, the affinity variant comprises a total of 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 or less substitutions in the CDR and / or FR sequences.

[0143] In certain embodiments, the anti-CD276 antibodies and antigen-binding fragments thereof comprise one, two or three CDR sequences having at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) sequence identity to those(s) listed in Table 1, while retaining similar or even higher levels of binding affinity for CD276 as its parent antibody.

[0144] In certain embodiments, anti-CD276 antibodies and antigen-binding fragments thereof comprise one or more variable region sequences having at least 80% (e.g., at least 85%, 88%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%) sequence identity to those(s) listed in Table 1, while retaining a similar or even higher level of binding affinity for CD276 as its parent antibody. In some embodiments, a total of 1-10 amino acids have been substituted, inserted or deleted in a sequence selected from those(s) listed in Table 1. In some embodiments, the substitutions, insertions or deletions occur in regions outside the CDRs (i.e., in the FRs).

[0145] Glycosylation variants The anti-CD276 antibodies and antigen-binding fragments provided herein also encompass glycosylation variants, which can be obtained to increase or decrease the degree of glycosylation of the antibody or antigen-binding fragment thereof.

[0146] The antibody or antigen-binding fragment thereof may comprise one or more amino acid residues having a side chain to which a carbohydrate moiety (e.g., an oligosaccharide structure) can be attached. Glycosylation of the antibody is usually either N-linked or O-linked. N-linked refers to the attachment of the carbohydrate moiety to the side chain of an asparagine residue in a tripeptide sequence, such as asparagine-X-serine and asparagine-X-threonine, where X is any amino acid except proline. O-linked glycosylation refers to the attachment of one of the sugars N-acetylgalactosamine, galactose or xylose to a hydroxyamino acid, most commonly serine or threonine. Removal of native glycosylation sites can be conveniently accomplished by, for example, altering the amino acid sequence to substitute one of the above tripeptide sequences (for N-linked glycosylation sites) or a serine or threonine residue present in the sequence (for O-linked glycosylation sites). New glycosylation sites can be created in an analogous manner by introducing such tripeptide sequences or serine or threonine residues.

[0147] Cysteine ​​engineered mutants The anti-CD276 antibodies and antigen-binding fragments provided herein also include cysteine ​​engineered variants, which contain one or more introduced free cysteine ​​amino acid residues.

[0148] Free cysteine ​​residues are those that are not part of disulfide bridges.Cysteine ​​engineered mutants are useful for conjugation with cytotoxic and / or imaging compounds, labels or radioisotopes, for example, via maleimide or haloacetyl, among others, at engineered cysteine ​​sites.Methods for engineering antibody or antigen-binding fragments to introduce free cysteine ​​residues are known in the art, for example, see WO2006 / 034488.

[0149] Fc variants The anti-CD276 antibodies and antigen-binding fragments provided herein also encompass Fc variants that contain one or more amino acid residue modifications or substitutions in the Fc region and / or hinge region.

[0150] In certain embodiments, the anti-CD276 antibody or antigen-binding fragment contains one or more amino acid substitutions that improve pH-dependent binding to the neonatal Fc receptor (FcRn). Such variants may have an extended pharmacokinetic half-life because they bind to FcRn at acidic pH, allowing them to escape degradation in lysosomes and then be translocated and released outside the cell. Methods for engineering antibodies and antigen-binding fragments thereof to improve binding affinity to FcRn are well known in the art, see, e.g., Vaughn, D. et al, Structure, 6(1):63-73, 1998; Kontermann, R. et al, Antibody Engineering, Volume 1, Chapter 27: Engineering of the Fc region for improved PK, published by Springer, 2010; Yeung, Y. et al, Cancer Research, 70:3269-3277(2010); and Hinton, P. et al, J. Immunology, 176:346-356(2006).

[0151] In certain embodiments, the anti-CD276 antibody or antigen-binding fragment comprises one or more amino acid substitutions that alter antibody-dependent cellular cytotoxicity (ADCC). Certain amino acid residues in the CH2 domain of the Fc region can be substituted to provide enhanced ADCC activity. Alternatively, or in addition, carbohydrate structures on the antibody can be altered to enhance ADCC activity. Methods for altering ADCC activity by antibody engineering have been described in the art, e.g., Shields RL.et al., J Biol Chem.2001.276(9):6591-604; Idusogie EE.et al., J Immunol.2000.164(8):4178-84; Steurer W.et al., J Immunol.1995,155(3):1165-74; Idusogie EE.et al., J Immunol.2001,166(4):2571-5; Lazar GA.et al., PNAS,2006,103(11):4005-4010; Ryan MC.et al., Mol.Cancer Ther.,2007,6:3009-3018; Richards JO,.et al., Mol Cancer See Ther. 2008, 7(8):2517-27; Shields R Let al, J. Biol. Chem, 2002, 277:26733-26740; Shinkawa T. et al, J. Biol. Chem, 2003, 278:3466-3473.

[0152] In certain embodiments, the anti-CD276 antibody or antigen-binding fragment contains one or more amino acid substitution(s) that alter complement dependent cytotoxicity (CDC), e.g., by improving or reducing C1q binding and / or CDC (see, e.g., WO99 / 51642; Duncan & Winter Nature 322:738-40 (1988); U.S. Patent No. 5,648,260; U.S. Patent No. 5,624,821) and WO94 / 29351 for other examples of Fc region variants.

[0153] In certain embodiments, the anti-CD276 antibody or antigen-binding fragment thereof comprises one or more amino acid substitutions at the interface of the Fc region to facilitate and / or promote heterodimerization. These modifications include the introduction of a protuberance into the first Fc polypeptide and a cavity into the second Fc polypeptide, where the protuberance can be positioned in the cavity to promote the interaction of the first and second Fc polypeptides to form a heterodimer or complex. Methods for making antibodies with these modifications are known in the art, for example, as described in U.S. Patent No. 5,731,168.

[0154] antigen binding fragment Anti-CD276 antigen-binding fragments are also provided herein. Various types of antigen-binding fragments are known in the art and can be developed based on the anti-CD276 antibodies provided herein, including, for example, the exemplary antibodies whose CDR and FR sequences are shown in Table 1, and various variants thereof (e.g., affinity variants, glycosylation variants, Fc variants, cysteine ​​engineered variants, etc.).

[0155] In certain embodiments, an anti-CD276 antigen-binding fragment provided herein is a camelized single domain antibody, a single chain Fv fragment (scFv), dsFv, (dsFv)2, Fv fragment, Fab, Fab', F(ab')2, nanobody, domain antibody, single domain antibody or bivalent domain antibody.

[0156] Various techniques can be used to produce such antigen-binding fragments. Exemplary methods include enzymatic digestion of intact antibodies (see, e.g., Morimoto et al., Journal of Biochemical and Biophysical Methods 24:107-117 (1992); and Brennan et al., Science, 229:81 (1985)), recombinant expression by host cells such as E. Coli (e.g., for Fab, Fv and ScFv antibody fragments), screening from a phage display library as discussed above (e.g., for ScFv), and chemical coupling of two Fab'-SH fragments to form F(ab')2 fragments (Carter et al., Bio / Technology 10:163-167 (1992)). Other techniques for producing antibody fragments will be apparent to those skilled in the art.

[0157] In certain embodiments, the antigen-binding fragment is an scFv. The production of scFv is described, for example, in WO93 / 16185; U.S. Patent Nos. 5,571,894 and 5,587,458. scFv can be fused to effector protein at either amino or carboxy terminus to provide fusion protein (see, for example, Antibody Engineering, ed. Borrebaeck).

[0158] Conjugates In some embodiments, the anti-CD276 antibody and antigen-binding fragment thereof are linked to one or more conjugates, and optionally the conjugates are covalently linked either directly or through a linker. A conjugate is a non-proteinaceous moiety that can bind to an antibody or its antigen-binding fragment. It is contemplated that various conjugates may be linked to the antibody or antigen-binding fragment provided herein (see, for example, "Conjugate Vaccines", Contributions to Microbiology and Immunology, JM Cruse and RE Lewis, Jr. (eds.), Carger Press, New York, (1989)). These conjugates may be linked to the antibody or antigen-binding fragment by covalent binding, affinity binding, intercalation, coordinate binding, complex formation, association, blending or addition, among other methods. In some embodiments, the conjugate comprises a clearance modifier, a chemotherapeutic agent, a toxin, a radioisotope, a lanthanide, a luminescent label, a fluorescent label, an enzyme substrate label, a DNA alkylating agent, a topoisomerase inhibitor, a tubulin binding agent or other anti-cancer drug.

[0159] In certain embodiments, the antibodies and antigen-binding fragments disclosed herein may be engineered to contain designated sites outside the epitope-binding portion that can be utilized for binding to one or more conjugates. For example, such sites may include one or more reactive amino acid residues, such as cysteine ​​or histidine residues, to facilitate covalent binding to a conjugate.

[0160] In certain embodiments, the antibody may be indirectly linked to the conjugate or through another conjugate.For example, the antibody or antigen-binding fragment may be conjugated to biotin, and then indirectly conjugated to a second conjugate that is conjugated to avidin.The conjugate may be a toxin (e.g., a chemotherapeutic agent), a detectable label (e.g., a radioisotope, a lanthanide, a luminescent label, a fluorescent label, or an enzyme-substrate label).

[0161] A "toxin" can be any agent that is harmful to cells or can damage or kill cells. Examples of toxins include, but are not limited to, taxol, cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, doxorubicin, daunorubicin, dihydroxyanthracenedione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine, propranolol, puromycin and its analogs, antimetabolites (e.g., methotrexate, 6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracil decarbazine), alkaloids, and the like. Killing agents (e.g., mechlorethamine, thioepachlorambucil, melphalan, carmustine (BSNU) and lomustine (CCNU), cyclophosphamide, busulfan, dibromomannitol, streptozotocin, mitomycin C and cis-dichlorodiamineplatinum(II) (DDP) cisplatin), anthracyclines (e.g., daunorubicin (formerly daunomycin) and doxorubicin), antibiotics (e.g., dactinomycin (formerly actinomycin), bleomycin, mithramycin and anthramycin (AMC)), and antimitotic agents (e.g., vincristine and vinblastine).

[0162] Examples of detectable labels include fluorescent labels (e.g., fluorescein, rhodamine, dansyl, phycoerythrin, or Texas Red), enzyme substrate labels (e.g., horseradish peroxidase, alkaline phosphatase, luciferase, glucoamylase, lysozyme, saccharide oxidase, or β-D-galactosidase), radioisotopes (e.g., 123 I, 124 I, 125 I, 131 I, 35 S, 3 H, 111 In, 112 In, 14 C. 64 Cu, 67 Cu, 86 Y, 88 Y, 90 Y, 177 Lu, 211 At, 186 Re, 188 Re, 153 Sm, 212 Bi and 32 P, other lanthanides, luminescent labels), chromophore moieties, digoxigenin, biotin / avidin, DNA molecules or gold for detection.

[0163] In certain embodiments, the conjugate may be a pharmacokinetic modifying moiety that serves to increase the half-life of the antibody. Illustrative examples include water-soluble polymers, such as PEG, carboxymethylcellulose, dextran, polyvinyl alcohol, polyvinylpyrrolidone, ethylene glycol / propylene glycol copolymers, and the like. The polymer may be of any molecular weight, branched or unbranched. The number of polymers attached to the antibody may vary, and when more than one polymer is attached, it may be the same molecule or different molecules.

[0164] In certain embodiments, the conjugate may be a purification moiety, such as a magnetic bead.

[0165] In certain embodiments, the antibodies and / or antigen-binding fragments thereof provided herein are used as the basis of conjugates.

[0166] Polynucleotides and Recombinant Methods The present disclosure provides isolated polynucleotides that code for anti-CD276 antibodies and their antigen-binding fragments.The DNA that codes for monoclonal antibodies can be easily isolated and sequenced using conventional procedures (for example, by using oligonucleotide probes that can specifically bind to the genes that code for the heavy and light chains of antibodies).The coding DNA can also be obtained by synthetic methods.

[0167] The isolated polynucleotides encoding anti-CD276 antibodies and antigen-binding fragments thereof can be inserted into vectors for further cloning (amplification of DNA) or expression using recombinant techniques known in the art. Numerous vectors are available. Vector components generally include, but are not limited to, one or more of the following: a signal sequence, an origin of replication, one or more marker genes, an enhancer element, a promoter (e.g., SV40, CMV, EF-1α), and a transcription termination sequence.

[0168] In some embodiments, vector systems include mammalian, bacterial, yeast systems, and the like, including but not limited to plasmids such as pALTER, pBAD, pcDNA, pCal, pL, pET, pGEMEX, pGEX, pCI, pCMV, pEGFP, pEGFT, pSV2, pFUSE, pVITRO, pVIVO, pMAL, pMD18-T, pMONO, pSELECT, pUNO, pDUO, Psg5L, pBABE, pWPXL, pBI, p15TV-L, pPro18, pTD, pRS420, pLexA, pACT2.2, and other laboratory and commercially available vectors. Suitable vectors can include plasmids or viral vectors (e.g., replication-defective retroviruses, adenoviruses, and adeno-associated viruses).

[0169] A vector containing a polynucleotide sequence encoding an antibody or antigen-binding fragment can be introduced into a host cell for cloning or gene expression. Suitable host cells for cloning or expressing DNA in a vector herein include the prokaryotes, yeast or higher eukaryotic cells described above. Suitable prokaryotes for this purpose include eubacteria, such as gram-negative or gram-positive organisms, e.g., Escherichia, e.g., E. coli, Enterobacter, Erwinia, Klebsiella, Proteus, Salmonella, e.g., Salmonella typhimurium, Serratia, e.g., Serratia marcescens, and the like. marcescans and Shigella, as well as Bacilli such as B. subtilis and B. licheniformis, Pseudomonas such as P. aeruginosa, and Enterobacteriaceae such as Streptomyces.

[0170] In addition to prokaryotes, eukaryotic microbes such as filamentous fungi or yeast are suitable cloning or expression hosts for anti-CD276 antibody-encoding vectors. Saccharomyces cerevisiae, or common baker's yeast, is the most commonly used among lower eukaryotic host microorganisms. However, Schizosaccharomyces pombe; Kluyveromyces hosts such as K. lactis, K. fragilis (ATCC 12,424), K. bulgaricus (ATCC 16,045), K. wickeramii (ATCC 24,178), K. waltii (ATCC 56,500), K. drosophilarum (ATCC 36,906), K. thermotolerans, and K. marxianus; Yarrowia (EP 402,226); Pichia pastoris; pastoris (EP 183,070); Candida; Trichoderma reesia (EP 244,234); Neurospora crassa; Schwanniomyces, such as Schwanniomyces occidentalis; and filamentous fungi, such as Neurospora, Penicillium, Tolypocladium, and Aspergillus hosts, such as A. nidulans and A. niger, are publicly available and useful herein.

[0171] The host cell suitable for expressing the glycosylated antibody or antigen fragment provided herein is derived from a multicellular organism. Examples of vertebrate cells include plants and insect cells. Numerous baculovirus strains and mutants and corresponding permissive insect host cells have been identified from hosts such as Spodoptera frugiperda (caterpillar), Aedes aegypti (mosquito), Aedes albopictus (mosquito), Drosophila melanogaster (fruiflly) and Bombyx mori. Various virus strains for transfection are publicly available, such as the L-1 mutant of Autographa californica NPV and the Bm-5 strain of Bombyx mori NPV, and such viruses may be used as viruses in accordance with the invention herein, particularly for transfection of Spodoptera frugiperda cells. Plant cell cultures of cotton, corn, potato, soybean, petunia, tomato, and tobacco may also be used as hosts.

[0172] However, interest has been greatest in vertebrate cells, and propagation of vertebrate cells in culture (tissue culture) has become a routine procedure. Examples of useful mammalian host cell lines include the SV40 transformed monkey kidney CV1 line (COS-7, ATCC CRL1651); human embryonic kidney line (293 or 293 cells subcloned for growth in suspension culture, Graham et al., J. Gen Virol. 36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL10); Chinese hamster ovary cells / -DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci. USA 77:4216 (1980)); mouse Sertoli cells (TM4, Mather, Biol. Reprod. 23:243-251 (1980)); monkey kidney cells (CV1 ATCC CCL70); African green monkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCC CRL1442); human lung cells (W138, ATCC CCL75); human liver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals NYAcad. Sci. 383:44-68 (1982)); MRC5 cells; FS4 cells; and a human hepatoma line (Hep G2).

[0173] Host cells are transformed with the above-described expression or cloning vectors for anti-CD276 antibody production and cultured in conventional nutrient media modified as necessary to induce promoters, select transformants, or amplify the genes encoding the desired sequences. In another embodiment, antibodies can be produced by homologous recombination as known in the art.

[0174] The host cells used to produce the antibodies or antigen-binding fragments provided herein can be cultured in a variety of media. Commercially available media such as Ham's F10 (Sigma), Minimum Essential Medium (MEM) (Sigma), RPMI-1640 (Sigma) and Dulbecco's Modified Eagle Medium (DMEM) (Sigma) are suitable for culturing the host cells. In addition, any of the media described in Ham et al., Meth. Enz. 58:44 (1979), Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal. Biochem. 102:255 (1980), U.S. Pat. Nos. 4,767,704; 4,657,866; 4,927,762; 4,560,655; or 5,122,469; WO 90 / 03430; WO 87 / 00195; or Reissued U.S. Pat. No. 30,985 may be used as a culture medium for the host cells. Any of these media may be supplemented as necessary with hormones and / or other growth factors (such as insulin, transferrin or epidermal growth factor), salts (such as sodium chloride, calcium, magnesium and phosphate), buffers (such as HEPES), nucleotides (such as adenosine and thymidine), antibiotics (such as GENTAMYCIN™ drug), trace elements (defined as inorganic compounds usually present at final concentrations in the micromolar range) and glucose or an equivalent energy source. Any other necessary nutritional supplements may also be included at appropriate concentrations that would be known to one of skill in the art. Culture conditions such as temperature, pH, etc. are those previously used with the host cell selected for expression and will be apparent to one of skill in the art.

[0175] When using recombinant techniques, antibodies can be produced intracellularly in the periplasmic space or directly secreted into the medium. If the antibody is produced intracellularly, as a first step, particulate debris, either host cells or lysed fragments, are removed, for example, by centrifugation or ultrafiltration. Carter et al., Bio / Technology 10:163-167 (1992) describes a procedure for isolating antibodies secreted into the periplasmic space of E. coli. Briefly, cell paste is thawed in the presence of sodium acetate (pH 3.5), EDTA, and phenylmethylsulfonyl fluoride (PMSF) for about 30 minutes. Cell debris can be removed by centrifugation. If the antibody is secreted into the medium, the supernatant from such an expression system is generally first concentrated using a commercially available protein concentration filter, for example, an Amicon or Millipore Pellicon ultrafiltration unit. Protease inhibitors such as PMSF may be included in any of the above steps to inhibit proteolysis and antibiotics may be included to prevent the growth of adventitious contaminants.

[0176] The anti-CD276 antibodies and antigen-binding fragments thereof prepared from the cells can be purified using, for example, hydroxylapatite chromatography, gel electrophoresis, dialysis, DEAE-cellulose ion exchange chromatography, ammonium sulfate precipitation, salting out, and affinity chromatography, with affinity chromatography being the preferred purification technique.

[0177] In certain embodiments, solid-phase immobilized protein A is used for immunoaffinity purification of antibodies and their antigen-binding fragments. The suitability of protein A as an affinity ligand depends on the species and isotype of any immunoglobulin Fc domain present in the antibody. Protein A can be used to purify antibodies based on human gamma 1, gamma 2, or gamma 4 heavy chains (Lindmark et al., J. Immunol. Meth. 62:1-13 (1983)). Protein G is recommended for all mouse isotypes and for human gamma 3 (Guss et al., EMBO J. 5:1567 1575 (1986)). The matrix to which the affinity ligand is attached is most often agarose, although other matrices are available. Mechanically stable matrices such as controlled pore glass or poly(styrenedivinyl)benzene allow for faster flow rates and shorter processing times than can be achieved with agarose. If the antibody contains a CH3 domain, Bakerbond ABX.TM. resin (JT Baker, Phillipsburg, NJ) is useful for purification. Other techniques for protein purification, such as fractionation on ion exchange columns, ethanol precipitation, reverse phase HPLC, chromatography on silica, chromatography on heparin SEPHAROSE™, chromatography on anion or cation exchange resins (such as polyaspartic acid columns), isoelectric focusing, SDS-PAGE and ammonium sulfate precipitation, are also available depending on the antibody to be recovered.

[0178] After any preliminary purification step(s), the mixture containing the antibody of interest and contaminants may be subjected to low pH hydrophobic interaction chromatography using an elution buffer at a pH between about 2.5 and 4.5, preferably performed at a low salt concentration (e.g., about 0-0.25 M salt).

[0179] CAR In another aspect, the present disclosure also provides a chimeric antigen receptor (CAR) comprising an antigen-binding domain, a transmembrane domain, a costimulatory signaling region and a TCR signaling domain, wherein the antigen-binding domain specifically binds to CD276 and comprises an antigen-binding fragment provided herein. In certain embodiments, the antigen-binding fragment is a Fab or scFv. In certain embodiments, the CAR provided herein is bispecific. The CAR can further specifically bind to a second antigen other than CD276 or a second epitope on CD276. In certain embodiments, the second antigen is a tumor antigen, a tumor-associated antigen or an immune-related target as described above. The TCR signaling domain can be selected from the group consisting of intracellular signal region sequences of CD3zeta, FccRIgamma, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR or combinations thereof. The transmembrane region can comprise the transmembrane region of CD3, CD4, CD8 or CD28. In certain embodiments, the second antigen is an immunosuppressive molecule such as PD-L1, SIRPα, CD47, or B2M.

[0180] In another aspect, the present disclosure also provides a nucleic acid sequence encoding the above-mentioned CAR and a cell or vector comprising such a nucleic acid sequence or a cell genetically modified to express the CAR provided herein. The cell may be an immune cell, and optionally the immune cell is a T lymphocyte, a NK cell, a monocyte, a macrophage, or a NKT lymphocyte.

[0181] Pharmaceutical Compositions The present disclosure further provides pharmaceutical compositions comprising an anti-CD276 antibody, or antigen-binding fragment thereof, and one or more pharma- ceutically acceptable carriers.

[0182] Pharmaceutically acceptable carriers for use in the pharmaceutical compositions disclosed herein can include, for example, pharma- ceutically acceptable liquid, gel or solid carriers, aqueous vehicles, non-aqueous vehicles, antibacterial agents, isotonicity agents, buffers, antioxidants, anesthetics, suspending / dispensing agents, sequestering or chelating agents, diluents, adjuvants, excipients or non-toxic auxiliary substances, other ingredients known in the art, or various combinations thereof.

[0183] Suitable ingredients can include, for example, antioxidants, bulking agents, binders, disintegrants, buffers, preservatives, lubricants, flavorings, thickening agents, coloring agents, emulsifiers, or stabilizers such as sugars and cyclodextrins.Suitable antioxidants can include, for example, methionine, ascorbic acid, EDTA, sodium thiosulfate, platinum, catalase, citric acid, cysteine, thioglycerol, thioglycolic acid, thiosorbitol, butylated hydroxyanisole, butylated hydroxytoluene, and / or propyl gallate.As disclosed herein, by including one or more antioxidants, such as methionine, in compositions comprising antibodies or antigen-binding fragments and conjugates as provided herein, the oxidation of the antibodies or antigen-binding fragments is reduced.This reduction in oxidation prevents or reduces the loss of binding affinity, thereby improving antibody stability and maximizing shelf life.Thus, in certain embodiments, compositions are provided that include one or more antibodies or antigen-binding fragments thereof as disclosed herein and one or more antioxidants, such as methionine. Further provided are methods for preventing oxidation, extending the shelf life, and / or improving the efficacy of antibodies or antigen-binding fragments as provided herein by combining the antibodies or antigen-binding fragments with one or more antioxidants, such as methionine.

[0184] To further illustrate, pharma- ceutically acceptable carriers can include, for example, aqueous vehicles such as sodium chloride injection, Ringer's injection, isotonic dextrose injection, sterile water injection or dextrose and lactated Ringer's injection, non-aqueous vehicles such as hydrogenated oils of vegetable origin, coconut oil, corn oil, sesame oil or peanut oil, antibacterial agents in bacteriostatic or fungistatic concentrations, isotonic agents such as sodium chloride or dextrose, buffers such as phosphate or citrate buffers, antioxidants such as sodium bisulfate, local anesthetics such as procaine hydrochloride, suspending and dispersing agents such as sodium carboxymethylcellulose, hydroxypropylmethylcellulose or polyvinylpyrrolidone, emulsifying agents such as polysorbate 80 (TWEEN-80), sequestering or chelating agents such as EDTA (ethylenediaminetetraacetic acid) or EGTA (ethylene glycol tetraacetic acid), ethyl alcohol, polyethylene glycol, propylene glycol, sodium hydroxide, hydrochloric acid, citric acid or lactic acid. Antibacterial agents used as carriers may be added to the pharmaceutical composition in multi-dose containers, and include phenol or cresol, mercurials, benzyl alcohol, chlorobutanol, methyl and propyl p-hydroxybenzoic acid esters, thimerosal, benzalkonium chloride and benzethonium chloride.Suitable excipients can include, for example, water, saline, dextrose, glycerol or ethanol.Suitable non-toxic auxiliary substances can include, for example, wetting agents or emulsifiers, pH buffers, stabilizers, dissolution promoters, or agents such as sodium acetate, sorbitan monolaurate, triethanolamine oleate or cyclodextrin.

[0185] The pharmaceutical compositions can be liquid solutions, suspensions, emulsions, pills, capsules, tablets, sustained release formulations or powders. Oral formulations can include standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, polyvinylpyrrolidone, sodium saccharin, cellulose, magnesium carbonate, etc.

[0186] In certain embodiments, the pharmaceutical composition is formulated into an injectable composition. The injectable pharmaceutical composition can be prepared in any conventional form, such as liquid solution, suspension, emulsion, or solid form suitable for making liquid solution, suspension, or emulsion. Preparations for injection can include sterile and / or non-pyrogenic solutions prepared for injection, sterile dry soluble preparations such as freeze-dried powders prepared to be combined with a solvent immediately before use, including subcutaneous tablets, sterile suspensions prepared for injection, sterile dry insoluble preparations prepared to be combined with a vehicle immediately before use, and sterile and / or non-pyrogenic emulsions. Solutions can be aqueous or non-aqueous.

[0187] In certain embodiments, unit dose parenteral preparations are packaged in ampoules, vials or syringes with needles. All preparations for parenteral administration must be sterile and non-pyrogenic as known and practiced in the art.

[0188] In certain embodiments, a sterile, lyophilized powder is prepared by dissolving an antibody or antigen-binding fragment as disclosed herein in a suitable solvent. The solvent may contain excipients that improve the stability or other pharmacological components of the powder or a reconstituted solution prepared from the powder. Excipients that may be used include, but are not limited to, water, dextrose, sorbital, fructose, corn syrup, xylitol, glycerin, glucose, sucrose or other suitable agents. The solvent may contain a buffer such as citric acid, sodium or potassium phosphate, or other such buffers known to those of skill in the art, in one embodiment at about neutral pH. Subsequent sterile filtration of the solution followed by lyophilization under standard conditions known to those of skill in the art provides the desired formulation. In one embodiment, the resulting solution is apportioned into vials for lyophilization. Each vial may contain a single dose or multiple doses of an anti-CD276 antibody or antigen-binding fragment thereof or composition thereof. Overfilling the vial with a small amount (e.g., about 10%) beyond that required for a dose or set of doses is permissible to facilitate accurate sample draws and accurate dosing. The lyophilized powder may be stored under appropriate conditions, such as at about 4° C. to room temperature.

[0189] Reconstitution of lyophilized powder with water for injection provides a formulation for use in parenteral administration.In one embodiment, sterile and / or non-pyrogenic water or other liquid suitable carrier is added to lyophilized powder for reconstitution.The exact amount varies according to the selected therapy given and can be empirically determined.

[0190] How to use The present disclosure also provides a method of treatment comprising administering to a subject in need thereof a therapeutically effective amount of an antibody or antigen-binding fragment thereof as provided herein, thereby treating or preventing a CD276-associated disease or condition. In some embodiments, the CD276-associated disease or condition is cancer, an autoimmune disease, an inflammatory disease, an adaptive immune disease, or an infectious disease.

[0191] Examples of cancers include, but are not limited to, non-small cell lung cancer (squamous / non-squamous), small cell lung cancer, renal cell carcinoma, colorectal cancer, colon cancer, ovarian cancer, breast cancer (including basal, ductal and lobular breast carcinoma), pancreatic cancer, gastric carcinoma, bladder cancer, esophageal cancer, mesothelioma, melanoma, head and neck cancer, thyroid cancer, sarcoma, prostate cancer, glioblastoma, cervical cancer, thymic carcinoma, melanoma, myeloma, mycosis fungoides, fungoids], Merkel cell carcinoma, hepatocellular carcinoma (HCC), fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteosarcoma and other sarcomas, synovium, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, lymphoid tumors, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, medullary thyroid carcinoma, papillary thyroid carcinoma, pheochromocytoma sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinoma, medullary carcinoma, bronchogenic lung carcinoma, hepatocellular carcinoma, cholangiocarcinoma, choriocarcinoma, Wilms' tumor, cervical cancer, testicular tumor, seminoma, classical Hodgkin's lymphoma (CHL), primary mediastinal large B-cell lymphoma, T-cell / histiocyte-rich B-cell lymphoma, acute lymphocytic leukemia, acute myeloid leukemia, acute myeloid leukemia, chronic myeloid (granulocytic) leukemia, chronic myeloid leukemia, chronic lymphocytic These include leukemia, polycythemia vera, mast cell derived tumors, EBV positive and negative PTLD and diffuse large B cell lymphoma (DLBCL), plasmablastic lymphoma, extranodal NK / T cell lymphoma, nasopharyngeal carcinoma, HHV8 associated primary effusion lymphoma, non-Hodgkin's lymphoma, multiple myeloma, Waldenstrom's hypergammaglobulinemia, heavy chain disease, myelodysplastic syndrome, hairy cell leukemia and myelodysplasia, primary CNS lymphoma, spinal axis tumor, brain stem glioma, astrocytoma, medulloblastoma, craniopharyogioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma and retinoblastoma.

[0192] In certain embodiments, the cancer is an adrenal gland tumor, AIDS-related cancer, alveolar soft part sarcoma, astrocytic tumor, bladder cancer, bone cancer, brain and spinal cord cancer, metastatic brain tumor, breast cancer, carotid globe tumor, cervical cancer, chondrosarcoma, chordoma, chromophobe renal carcinoma, clear cell carcinoma, colon cancer, colorectal cancer, cutaneous benign fibrous histiocytoma, desmoplastic small round cell tumor, ependymoma, Ewing's tumor, extraskeletal myxoid chondrosarcoma, fibrous ossification imperfecta, fibrous dysplasia, gallbladder or bile duct cancer, gastric cancer, gestational trophoblastic disease, germ cell tumor, head and neck cancer, hepatocellular carcinoma, pancreatic islet tumor, Kaposi's sarcoma, kidney cancer, leukemia, lipoma, leukemia ... Lipoma / benign lipomatous tumor, liposarcoma / malignant lipomatous tumor, liver cancer, lymphoma, lung cancer, medulloblastoma, melanoma, meningioma, multiple endocrine neoplasia, multiple myeloma, myelodysplastic syndrome, neuroblastoma, neuroendocrine tumor, ovarian cancer, pancreatic cancer, papillary thyroid carcinoma, parathyroid tumor, childhood cancer, peripheral nerve sheath tumor, pheochromocytoma, pituitary tumor, prostate cancer, posterior uveal melanoma, rare blood disorder, metastatic renal cancer, rhabdomyosarcoma-like tumor, rhabdomyosarcoma, sarcoma, skin cancer, soft tissue sarcoma, squamous cell carcinoma, gastric cancer, synovial sarcoma, testicular cancer, thymic carcinoma, thymoma, thyroid metastatic cancer and uterine cancer. In certain embodiments, the cancer is chemotherapy resistant.

[0193] In certain embodiments, the disease or condition is a hematological cancer selected from B-cell lymphoma. Examples of B-cell lymphoma include, but are not limited to, Hodgkin's lymphoma, non-Hodgkin's lymphoma (NHL), acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), multiple myeloma (MM), diffuse large B-cell lymphoma (DLBCL), marginal zone B-cell lymphoma (MZL), mantle cell lymphoma (MCL), Richter's syndrome, Burkitt's lymphoma, or follicular lymphoma.

[0194] Autoimmune diseases, including but not limited to: acquired immune deficiency syndrome (AIDS, a viral disease with an autoimmune component), alopecia areata, ankylosing spondylitis, antiphospholipid syndrome, autoimmune Addison's disease, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease (AIED), autoimmune lymphoproliferative syndrome (ALPS), autoimmune thrombocytopenic purpura (ATP), Behçet's disease, cardiomyopathy, celiac sprue dermatitis herpetiformis; chronic fatigue immune dysfunction syndrome (CFIDS), chronic inflammatory demyelinating polyneuropathy (CIPD), cicatricial pemphigoid, cold agglutinin disease, CREST syndrome, Crohn's disease, Degos disease, dermatomyositis-juvenile, discoid lupus, essential mixed cryoglobulinemia, fibromyalgia-fibromyositis, Graves' disease, Guillain-Barre syndrome, Hashimoto's thyroiditis, idiopathic pulmonary fibrosis , idiopathic thrombocytopenic purpura (ITP), IgA nephropathy, insulin-dependent diabetes mellitus, juvenile chronic arthritis (Still's disease), juvenile rheumatoid arthritis, Meniere's disease, mixed connective tissue disease, multiple sclerosis, myasthenia gravis, malignant anemia, polyarteritis nodosa, polychondritis, polyglandular syndrome, polymyalgia rheumatica, polymyositis and dermatomyositis, primary agammaglobulinemia, primary biliary hepatitis These include cirrhosis, psoriasis, psoriatic arthritis, Raynaud's phenomenon, Reiter's syndrome, rheumatic fever, rheumatoid arthritis, sarcoidosis, scleroderma (also known as progressive systemic sclerosis (PSS) or systemic sclerosis (SS)), Sjogren's syndrome, stiff man syndrome, systemic lupus erythematosus, Takayasu's arteritis, temporal arteritis / giant cell arteritis, ulcerative colitis, uveitis, vitiligo, and Wegener's granulomatosis.

[0195] Inflammatory disorders include, for example, chronic and acute inflammatory disorders. Examples of inflammatory disorders include Alzheimer's disease, asthma, atopic allergy, allergy, atherosclerosis, bronchial asthma, eczema, glomerulonephritis, graft-versus-host disease, hemolytic anemia, osteoarthritis, sepsis, stroke, tissue and organ transplantation, vasculitis, diabetic retinopathy and ventilator-induced lung injury. In some embodiments, the CD276-associated condition is an inflammatory disease, for example, systemic lupus erythematosus (SLE), intestinal mucosal inflammation, colitis-associated wasting disease, multiple sclerosis, viral infection, rheumatoid arthritis, osteoarthritis, Cohn's disease and inflammatory bowel disease, psoriasis, systemic sclerosis, autoimmune diabetes, etc.

[0196] Infectious diseases include, but are not limited to, fungal infections, parasitic / protozoal infections, or chronic viral infections, such as malaria, coccidioiodmycosis immitis, histoplasmosis, onychomycosis, aspergillosis, blastomycosis, candidiasis albicans albicans, paracoccidioiomycosis, microsporidiosis, acanthamoeba keratitis, amebiasis, ascariasis, babesiosis, balantidiosis, Baylisascariasis, Chagas disease, clonorchiasis, Cochliomyia, cryptosporidiosis, diphyllobothriasis, dracunculiasis, echinococcosis, elephantiasis, enterobiasis, fascioliasis, filariasis, giardiasis, gnathostomiasis, hymenococcosis, isosporiasis, Katayama fever, leishmaniasis, Lyme disease, yokogawa fluke disease, myiasis, onchocerciasis, lice infestation, scabies, schistosomiasis, sleeping sickness, fecal nematode disease , tapeworm infection, toxocariasis, toxoplasmosis, trichinosis, trichuriasis, trypanosomiasis, helminth infection, hepatitis B (HBV), hepatitis C (HCV), herpes virus, Epstein-Barr virus, HIV, cytomegalovirus, herpes simplex virus type I, herpes simplex virus type II, human papillomavirus, adenovirus, human immunodeficiency virus I, human immunodeficiency virus II, Kaposi-West sarcoma-associated herpesvirus infection, Schingling virus (Torquetenovirus), human T-lymphotropic virus I, human T-lymphotropic virus II, varicella zoster, JC virus, or BK virus infection.

[0197] In certain embodiments, the subject is a human.

[0198] In another aspect, a method of treating a disease or condition in a subject that would benefit from modulation of CD276 activity is provided, comprising administering to a subject in need thereof a therapeutically effective amount of an antibody or antigen-binding fragment thereof provided herein. The term "disease or condition" may be used interchangeably herein with the term "CD276-associated disease or condition."

[0199] A therapeutically effective amount of an antibody or antigen-binding fragment thereof as provided herein will vary depending on a variety of factors known in the art, such as the subject's weight, age, past medical history, current drug applications, state of health and potential cross-reactions, allergies, sensitivities and adverse side effects, as well as the route of administration and extent of disease development, etc. Dosages may be proportionately reduced or increased by one skilled in the art (e.g., a physician or veterinarian) as indicated by these and other circumstances or requirements.

[0200] In certain embodiments, an antibody or antigen-binding fragment thereof as provided herein may be administered at a therapeutically effective dosage of about 0.01 mg / kg to about 100 mg / kg (e.g., about 0.01 mg / kg, about 0.5 mg / kg, about 1 mg / kg, about 2 mg / kg, about 3 mg / kg, about 5 mg / kg, about 10 mg / kg, about 15 mg / kg, about 20 mg / kg, about 25 mg / kg, about 30 mg / kg, about 35 mg / kg, about 40 mg / kg, about 45 mg / kg, about 50 mg / kg, about 55 mg / kg, about 60 mg / kg, about 65 mg / kg, about 70 mg / kg, about 75 mg / kg, about 80 mg / kg, about 85 mg / kg, about 90 mg / kg, about 95 mg / kg, or about 100 mg / kg). In certain of these embodiments, the antibody or antigen-binding fragment thereof is administered at a dosage of about 50 mg / kg or less, and in certain of these embodiments, the dosage is 10 mg / kg or less, 5 mg / kg or less, 3 mg / kg or less, 1 mg / kg or less, 0.5 mg / kg or less, or 0.1 mg / kg or less. In certain embodiments, the dosage may vary over the course of treatment. For example, in certain embodiments, the initial dosage may be higher than subsequent dosages. In certain embodiments, the dosage may vary over the course of treatment depending on the subject's response.

[0201] Dosage regimens can be adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a single dose can be administered or several divided doses can be administered over time.

[0202] The antibodies and antigen-binding fragments thereof disclosed herein can be administered by any route known in the art, such as, for example, parenteral (e.g., subcutaneous, intraperitoneal, intravenous including intravenous infusion, intramuscular or intradermal injection) or non-parenteral (e.g., oral, intranasal, intraocular, sublingual, rectal or topical) routes.

[0203] In some embodiments, the antibody or antigen-binding fragment thereof disclosed herein may be administered alone or in combination with one or more additional therapeutic procedures or agents. In some embodiments, the antibody or antigen-binding fragment thereof disclosed herein may be administered alone or in combination with a second therapeutic agent. For example, the antibody or antigen-binding fragment thereof disclosed herein may be administered in combination with a second therapeutic agent, such as a chemotherapeutic agent or an anti-cancer agent. In certain embodiments, the antibody or antigen-binding fragment thereof disclosed herein may be administered in combination with one or more immunosuppressive molecules, such as antagonists of CD24, CD47, SIRPα, PD-L1, or the beta-2 microglobulin subunit of major histocompatibility complex class I (B2M). The term "antagonist" as used herein may refer to any small molecule, small molecule, or microRNA, or antibody or antigen-binding fragment thereof, that blocks or inhibits the binding of CD24, CD47, SIRPα, PD-L1, or B2M to their respective binding partners to prevent the induction of immunosuppressive signals. In certain embodiments, the antibodies or antigen-binding fragments thereof disclosed herein are administered in combination with a PD-L1 antagonist, such as an anti-PD-L1 antibody or antigen-binding fragment thereof.

[0204] The term "anti-PD-L1 antibody" may refer to any known anti-PD-L1 antibody or antigen-binding fragment thereof, including, but not limited to, YN035 disclosed in WO2019196309A1 and MPDL3280A disclosed in WO2010077634A1.

[0205] In certain of these embodiments, the antibody or antigen-binding fragment thereof disclosed herein that is administered in combination with one or more additional therapeutic agents may be administered simultaneously with the one or more additional therapeutic agents, and in certain of these embodiments, the antibody or antigen-binding fragment thereof and the additional therapeutic agent(s) may be administered as part of the same pharmaceutical composition. However, an antibody or antigen-binding fragment thereof that is administered "in combination" with another therapeutic agent may not be administered simultaneously with the agent or in the same composition as the agent. An antibody or antigen-binding fragment thereof that is administered prior to or after another agent is considered to be administered "in combination" with the agent, as that phrase is used herein, even if the antibody or antigen-binding fragment thereof and the second agent are administered by different routes. When possible, additional therapeutic agents administered in combination with an antibody or antigen-binding fragment thereof disclosed herein will be administered according to a schedule listed on the package insert of the additional therapeutic agent, or according to protocols known in the art (Physicians' Desk Reference, 57th Ed; Medical Economics Company; ISBN: 1563634457; 57th edition (November 2002)).

[0206] In some embodiments, the present disclosure further provides a method of detecting the presence or amount of CD276 in a sample, comprising contacting the sample with an antibody or antigen-binding fragment thereof and determining the presence or amount of CD276 in the sample.

[0207] In some embodiments, the present disclosure further provides a method of diagnosing a CD276-associated disease or condition in a subject, the method comprising: a) obtaining a sample from the subject; b) contacting the sample obtained from the subject with an antibody or antigen-binding fragment thereof provided herein; c) determining the presence or amount of CD276 in the sample; and d) correlating the presence of CD276 with a CD276-associated disease or condition in the subject.

[0208] In some embodiments, the present disclosure also provides the use of an antibody or antigen-binding fragment thereof provided herein in the manufacture of a medicament for treating a CD276-related disease or condition in a subject, or in the manufacture of a diagnostic reagent for diagnosing a CD276-related disease or condition.

[0209] In another aspect, the present disclosure also provides a method of modulating CD276 activity in a cell expressing CD276, comprising exposing the cell expressing CD276 to an antibody or antigen-binding fragment thereof provided herein.

[0210] In another aspect, the present disclosure also provides a method of detecting the presence or amount of CD276 in a sample, comprising contacting the sample with an antibody or antigen-binding fragment thereof provided herein and determining the presence or amount of CD276 in the sample.

[0211] In another aspect, the present disclosure also provides a method of diagnosing a CD276-related disease or condition in a subject, the method comprising: a) obtaining a sample from the subject; b) contacting the sample obtained from the subject with an antibody or antigen-binding fragment thereof provided herein; c) determining the presence or amount of CD276 in the sample; and d) correlating the presence or amount of CD276 with the presence or status of a CD276-related disease or condition in the subject.

[0212] In another aspect, the disclosure also provides use of an antibody or antigen-binding fragment thereof provided herein in the manufacture of a medicament for treating a CD276-related disease or condition in a subject, the medicament further comprising a second therapeutic agent, e.g., a PD-L1 antagonist, optionally wherein the PD-L1 antagonist is an anti-PD-L1 antibody or antigen-binding fragment thereof.

[0213] In another aspect, the present disclosure also provides the use of an antibody or antigen-binding fragment thereof provided herein in the manufacture of a diagnostic reagent for diagnosing a CD276-related disease or condition.

[0214] In another aspect, the present disclosure also provides kits comprising an antibody or antigen-binding fragment thereof provided herein useful in detecting CD276, optionally recombinant CD276, cell surface expressed CD276, or cells expressing CD276. The term "recombinant," as used herein, refers to the artificial manipulation of one or more biological molecules, such as polynucleotide or polypeptide molecules, using one or more molecular biology techniques that render the biological molecule other than its native state.

[0215] In another aspect, the present disclosure also provides a method for stimulating a T cell-mediated immune response against a cell or tissue expressing CD276 in a mammal, comprising administering to the mammal an effective amount of a cell genetically modified to express a CAR comprising an antigen binding domain, a transmembrane domain, a costimulatory signaling region and a TCR signaling domain, wherein the antigen binding domain specifically binds to CD276 and comprises an antigen binding fragment provided herein. In certain embodiments, the antigen binding fragment is a Fab or scFv. In certain embodiments, the CAR provided herein is bispecific. The CAR can further specifically bind to a second antigen other than CD276 or a second epitope on CD276. In certain embodiments, the second antigen is a tumor antigen as described above. The TCR signaling domain can be selected from the group consisting of intracellular signal region sequences of CD3zeta, FccRIgamma, CD27, CD28, CD137, CD134, MyD88, CD40, CD278, TLR or combinations thereof. The transmembrane region may include the transmembrane region of CD3, CD4, CD8, or CD28. In certain embodiments, the second antigen is an immunosuppressive molecule, such as PD-L1, SIRPα, CD24, CD47, or B2M.

[0216] In another aspect, the present disclosure also provides a method for treating a mammal having a CD276-related disease or condition, comprising administering to the mammal an effective amount of a cell genetically modified to express a CAR (e.g., autologous T cell) provided herein, thereby treating the mammal.In certain embodiments, the CD276-related disease or condition is cancer.In certain embodiments, the mammal is a human subject.

[0217] The following examples are provided to better illustrate the claimed invention and should not be construed as limiting the scope of the invention. All specific compositions, materials and methods described below are within the scope of the invention, in whole or in part. These specific compositions, materials and methods do not limit the invention, but merely exemplify specific embodiments that fall within the scope of the invention. Those skilled in the art may develop equivalent compositions, materials and methods without exercising inventive ability and without departing from the scope of the invention. It will be understood that numerous variations can be made in the procedures described herein while remaining within the scope of the invention. It is the intention of the inventors that such variations are included within the scope of the invention. EXAMPLES

[0218] [Example 1] Hybridoma Development 1. Method 1.1 Immunization and Serum Titer Measurement 1.1.1 Immunogens and immunization strategies Cell immunization CHO-S cells overexpressing human CD276 protein (UniProt ID: Q5ZPR3, i.e., CHO-S-hCD276) or mouse CD276 protein (UniProt ID: Q8VE98, i.e., CHO-S-hCD276) were used as immunogens.

[0219] Protein immunization Recombinant human CD276 protein (SEQ ID NO: 346): Recombinant human CD276 protein was prepared by digesting human CD276 protein with enterokinase, and the extracellular domain of human CD276 was fused with a 6xHis tag and DDDDK (SEQ ID NO: 345).

[0220] Recombinant human CD276 protein (SEQ ID NO:346): LEVQVPEDPVVALVGTDATLCCSFSPEPGFSLAQLNLIWQLTDTKQLVHSFAE GQDQGSAYANRTALFPDLLAQGNASLRLQRVRVADEGSFTCFVSIRDFGSAA VSLQVAAPYSKPSMTLENKDLRPGDTVTITCSSYQGYPEAEVFWQDGQGVP LTGNVTTSQMANEQGLFDVHSILRVVLGANGTYSCLVRNPVLQQDAHSSVTI TPQRSPTGAVEVQVPEDPVVALVGTDATLRCSFSPEPGFSLAQLNLIWQLTDT KQLVHSFTEGRDQGSAYANRTALFPDLLAQGNASLRLQRVRVADEGSFTCFV SIRDFGSAAVSLQVAAPYSKPSMTLEPNKDLRPGDTVTITCSSYRGYPEAEVF WQDGQGVPLTGNVTTSQMANEQGLFDVHSVLRVVLGANGTYSCLVRNPVL QQDAHGSVTITGQPMTFPPEAHHHHHHDDDK

[0221] Balb / c and SJL mice were immunized as follows: Primary immunization was followed by several boosts until the animals developed sufficient antiserum titers suitable for hybridoma development.

[0222] [Table A]

[0223] 1.1.2 Immunization schedule Immunization schedule (Group 1)

[0224] [Table B]

[0225] Immunization schedule (Group 2)

[0226] [Table C]

[0227] Immunization schedule (Group 3)

[0228] [Table D]

[0229] Immunization schedule (Group 4)

[0230] [Table E]

[0231] Immunization schedule (group 5)

[0232] [Table F]

[0233] 1.1.3 Test bleed antiserum analysis Screening-test breeds were performed and evaluated by testing using FACS against CHO-S cell lines stably overexpressing human and / or mouse CD276 (CHO-S-hCD276 and / or CHO-S-mCD276).

[0234] Screening-test breeds were performed and evaluated by testing using an Elisa with the extracellular domain of recombinant human CD276 protein.

[0235] 1.2 Hybridoma generation and screening 1.2.1 Cell fusion and screening Fusion - Splenocyte fusions were performed on mice that responded best to immunization as determined by test breed FACS. Lymphocytes from spleens and lymph nodes were fused to the Sp2 / 0 cell line using an optimized electrofusion protocol. Multiple fusions were performed to ensure the success of cell fusion.

[0236] Screening and expansion - Fusions were plated into stacks of 96-well plates (2 x 10 per well). 4 ~10 5 Plates were monitored for growth and fed weekly. Wells with cell growth were screened by primary screening assays on days 10-14 using FACS and / or other viable assays such as Elisa. Multiple fusions were performed and screened for each targeted antigen. Positive parental clones that showed positive binding with CHO-S-CD276 and positive Elisa signal from the primary screen were expanded into 24-well plates for secondary screening.

[0237] Additional Antibody Screening - Following the primary screen, positive parental clones expanded into 24-well plates were screened again by the assay described in the Hybridoma Screening Funnel below.

[0238] Hybridomas of interest were selected to proceed to subcloning.

[0239] 1.2.2 Subcloning, screening and cryopreservation of hybridomas Subcloning - Parental hybridomas with the desired reactivity and isotype from the above screening funnel were then subcloned by multiple rounds of limiting dilution or single cell sorting until monoclones were obtained.

[0240] Screening and expansion--Subcloning plates were screened by protein or cell-based Elisa, and subclones with good binding ability were expanded to 24 wells for confirmation test. The specificity and cross-reactivity of these subclones were confirmed by FACS analysis. Briefly, parental CHO-S cells stably overexpressing Macaca_fascicularis CD276, CHO-S-hCD276, CHO-S cell line, and CHO-K1 S cell line stably overexpressing mouse CD276 were incubated with the antibodies produced by each subclone, respectively. Fluorescent dye-conjugated secondary antibodies were used to detect binding of primary antibodies to cells. Median fluorescence intensity was measured by FACS analysis.

[0241] Cryopreservation - The desired subclone cell lines were sequenced and further expanded in culture flasks for cryopreservation. 0.5–13.0 × 10 6 Four to six vials per cell line at 100 cells / vial were initially cryopreserved. If necessary, a master cell bank and a working cell bank were established for the selected most valuable cell lines.

[0242] 2.Results We found 43 antibodies with unique sequences that showed positive binding to CHO-S cells stably overexpressing human CD276 protein (CHO-S-hCD276) but not to parental CHO-S cells, suggesting that these antibodies recognize human CD276. Of these, 42 antibodies could bind to cynomolgus monkey CD276, and 11 antibodies could bind to mouse CD276 protein. The MFI of mouse antibodies staining CHO-S, CHO-S-hCD276, CHO-S-mCD276, and CHO-S-cynoCD276 (CHO-S-cynoCD276) detected by FACS is summarized in the following table (Table 5).

[0243] [Table 5]

[0244] [Example 2] Antibody characterization: affinity 1. Method 1.1 Cell-based binding affinity to SKOV3 cancer cell line The sequences of 31 murine antibodies from Table 5 were selected to generate and produce human IgG1 chimeric antibodies. The binding affinity of these antibodies as well as the benchmark antibodies enoblituzumab (see US Patent No. 8,802,091, especially MGA271 with construct designated hBRCA84D-2) and MGC018 (an antibody-drug-conjugate in which mAb MGA017 (human IgG1) is conjugated via a cleavable linker to the prodrug seco-DUocarmycin hydroxybenzamide azaindole (DUBA), an alkylating agent that can damage DNA in both dividing and non-dividing cells, thereby causing cell death) to SKOV3, a human patient-derived ovarian cancer cell line, was determined by FACS analysis.

[0245] The protocol for FAC analysis is described as follows.

[0246] 1. Cells were digested using Trypsin (1x). The collected cells were centrifuged at 300g for 3 minutes, and the supernatant was discarded.

[0247] 2. Cells were washed twice with FACS buffer by centrifugation at 300 g for 3 min and discarding the supernatant.

[0248] 3. Resuspend the cells and dilute them to 2*10 5 Cells / well were seeded onto assay plates in 50ul FACS buffer, then 50μl of primary antibody was added (primary antibody final concentrations: 5.00, 1.67, 0.56, 0.19, 0.06, 0.02, 0.01, 0.00μg / ml, or 20.00, 6.67, 2.22, 0.74, 0.25, 0.08, 0.03, 0.00μg / ml) and incubated at 4°C for 1 hour.

[0249] 4. Cells were washed twice by using the conditions in step 2. Cells were resuspended with 100 μl / well of diluted secondary antibody and incubated at 4° C. for 1 hour in the dark.

[0250] 5. Cells were washed twice by using the conditions in step 2. Cells were resuspended with 100 μl / well FACS buffer. Cells were kept in the dark for FACS analysis.

[0251] The binding affinity of the selected antibodies to SKOV3 is higher, lower, or similar to that of the benchmark antibody enoblituzumab (see Table 6 and Figure 1).

[0252] [Table 6]

[0253] 2. Protein-based affinity testing with Biacore (ChemPartner) Test conditions: Analyte:B7H3 Running buffer: HBS-EP + Flow rate: 30μL / min Capture: Ab, 10 μL / min for 60 seconds Injection of serially diluted B7H3 Contact time: 180 seconds Dissociation time: 400 seconds Regeneration: pH 1.5 Gly, 30 μL / min for 30 seconds Methods: Multiple cycle kinetics / affinity using capture Machine model: Biacore 8K(GE) Analysis temperature: 25℃

[0254] [Table 7]

[0255] 3. Expression patterns of B7H3 on several cancer cell lines B7H3 expression was detected by FACS using 6-D8-E7-A11. We found high expression levels of B7H3 on several cancer cell lines, including BxPC3 (pancreatic), MCF7 (breast), Dentroit562 (head and neck), RKO (colon) and SUN620 (stomach) (see Figure 2).

[0256] [Example 3] Antibody Characterization: ADCC 1. Method To determine the ADCC of anti-CD276 antibodies, 1 x 10 5 Seed 2 x 10 SKOV3 / well into a 96-well flat-bottom sterile plate. 4 Jurkat-NFAT-luciferase-CD16 were added as effector cells. Then, serially diluted antibodies were added to each well, and the plate was incubated at 37°C, 5% CO2 for 18 hours. Finally, the ADCC activity of the antibodies was evaluated by detecting luciferase activity.

[0257] 2.Results All our antibodies showed potent ADCC effects against SKOV3 cells (human ovarian cancer cell line). Some of the antibodies showed lower or similar EC 50 (Table 8 and FIG. 3), demonstrating that it is more potent in mediating ADCC effects against SKOV3 cells than enoblituzumab (MGA271).

[0258] [Table 8]

[0259] [Example 4] Antibody Characterization: CDC 1. Method To determine the CDC of anti-CD276 antibodies, CHO-S-hCD276 cells were resuspended in cell culture medium at 4E5 cells / mL and then added to a 96-well opaque-walled plate at 50 μL / well. Anti-CD276 antibodies were diluted in complete F-12K medium and added to a 96-well opaque-walled plate at 50 μL / well. Human serum complement was diluted in cell culture medium and added to the same plate at 50 μL / well. The mixture was incubated for 2 hours at 37°C in a CO2 incubator. CellTiter-Glo reagent for determining cytotoxicity was added at 50 μL / well and the mixture was incubated at room temperature for 10 minutes. The luminescence signal of live cells on a microplate reader was recorded.

[0260] 2.Results All anti-CD276 antibodies showed potent CDC effects on CHO-S-hCD276 cells, with lower EC compared to the benchmark antibody enoblituzumab (MGA271). 50 (See Table 9 and Figure 4).

[0261] [Table 9]

[0262] [Example 5] Antibody characterization: indirect ADC cytotoxicity 1. Method Fab-ZAP is a chemical conjugate of goat anti-human monovalent antibody (secondary antibody) and saporin, a ribosome-inactivating protein. Fab-ZAP is used to determine the internalization ability of antibodies. In this assay, 80 μL of SKOV-3 cells were plated at 2000 cells / well in a 96-well plate and incubated overnight at 37°C. Anti-CD276 antibody was then added at 40 μL / well. Fab-ZAP human dilution was added at 40 μL / well and incubated at 37°C in a CO2 incubator for 96 hours. CellTiter-Glo reagent for determining cellular cytotoxicity was added at 100 μL / well and incubated at room temperature for 10 minutes. The luminescence signal of live cells on a microplate reader was recorded.

[0263] 2.Results All anti-CD276 antibodies had lower or similar IC compared to the benchmark antibody MGC018. 50 showed potent indirect ADC effects on SKOV3 cells (Table 10, Figure 5), indicating that they are potential candidates for generating ADCs.

[0264] [Table 10]

[0265] [Example 6] In vivo efficacy of antibodies in treating subcutaneous MC-38-hCD276 murine colon carcinoma in female C57BL / 6 mice 1. Research design and methods Several monoclonal antibodies with murine IgG2a Fc were constructed and expressed for in vivo efficacy studies.

[0266] 1. MC-38-hCD276 (B7H3) tumor cells were maintained in vitro in DMEM medium supplemented with 10% fetal bovine serum at 37°C in an atmosphere of 5% CO2 in air. Cells in logarithmic growth phase were harvested and quantified by cell counter prior to tumor inoculation.

[0267] 2. Each mouse was subcutaneously inoculated with MC-38-hCD276 (B7H3) tumor cells (1×10^6) in 0.1 ml of PBS in the right hind flank region for tumor development. The date of randomization is indicated as day 0, and dosing begins on day 0.

[0268] 3. The average tumor size is approximately 50-60 mm 3 When the IL-16 concentration was reached, randomization was initiated. Sixty mice were enrolled in this study. All animals were randomly assigned to seven study groups. Randomization was performed based on a randomized block design.

[0269] 4. Tumor volumes were measured twice weekly in two dimensions using calipers and volumes were expressed in mm using the formula: V = (L × W × W) / 2. 3 where V is the tumor volume, L is the tumor length (longest tumor dimension), and W is the tumor width (longest tumor dimension perpendicular to L). Dosing and tumor size and body weight measurements were performed in a laminar flow cabinet (see Table 11, Figure 6).

[0270] 5. Atezolizumab (anti-PD-L1 antibody also known as Tecentriq or MPDL3280A, see WO2010077634A1) and Antengene-084M (Fab sequence of MGA271 constructed with mouse IgG2a (see US Patent No. 8,802,091B)) were used as controls.

[0271] [Table 11]

[0272] 2.Results As shown in Figure 6, some of the anti-CD276 antibodies showed strong in vivo efficacy. In particular, 25-C8-D7-C5 murine IgG2a showed higher tumor inhibition than Antengene-084M murine IgG2a.

[0273] [Example 7] Antibody ADC in vivo efficacy testing 1. Research design and methods To evaluate the ADC potential of the antibodies, antibody conjugation with VC-MMAE was performed at ChemPartner. A series of VC-MMAE conjugated antibodies was obtained, details of which are shown in Table 12.

[0274] [Table 12]

[0275] Calu-6 tumor cells (5 × 10 cells) in 0.1 ml of PBS were injected into the right front flank region of each Balb / c nude mouse for the Calu-6 study for tumor development. 6 The average tumor size was approximately 122 mm 3 Randomization begins when the IL-16 expression level is reached. Sixty mice were enrolled in this study. The date of randomization is designated as day 0, and dosing begins on day 0.

[0276] 2.Results The therapeutic efficacy of the test substances in treating subcutaneous human lung cancer Calu-6 in Balb / c nude mice was investigated in this study. No obvious weight loss, mortality or toxic reactions were observed with the designed dosing regimen during the efficacy study. On day 24, MGC018, 10-G6-C4-B2, 16-C6-F7-F5, 15-C8-B5-G7 and 18-F9-D8-G7 at 3 mg / kg as single agents each show significant antitumor effects on Calu-6 model in Balb / c nude mice. The results are shown in Figure 7 and Table 13.

[0277] [Table 13]

[0278] [Example 8] Antibody T cell activation (MLR assay) test 1. Research design and methods dc induction Monocyte cells were cultured at 5 × 10 6 The monocytes were resuspended in 5% CO and then cultured in 6-well plates. On day 2, 2 ml / well of fresh complete medium supplemented with 2 U / ml dendritic cell culture factors was added for another 3 days of culture. Monocytes were then differentiated into immature dendritic cells (iDCs). After stimulation with 2 U / ml dendritic cell maturation factors for 48 h, iDCs differentiate into mature dendritic cells.

[0279] Antibody digestion 25 μg of hIgG1 and 3 μL of 10×Glyco buffer were mixed, then PBS was added to make a total reaction volume of 30 μl. 1 μl of IdeZ protease was added, then incubated at 37° C. for 30 minutes. 10 μl of Protein A / G beads were added in 1 mL of PBS and washed twice. The beads were resuspended in the reaction solution from the above step.

[0280] The tube was placed on a magnet for 1 min at room temperature, F(ab)2 was in the supernatant and Fc was captured by the beads.

[0281] MLR assay T cells were seeded at 200,000 cells / well and mDCs at 20,000 cells / well.

[0282] Cells were treated with PBS, IgG1, 25-C8-D7-C5, 30-C7-C11-D4, BMK (MGA271) or their Fabs (final concentration 5 μg / ml). After 24 hours, supernatants were collected and tested for human IL-2 and IFNγ using Elisa.

[0283] 2.Results As shown in Figures 8 and 9, 30-C7-C11-D4, but not 25-C8-D7-C5 and BMK (MGA271), can activate T cell activation.

[0284] [Example 9] Antibody humanization and PTM optimization 9.1 Cell-Based Affinity Testing of Humanized Antibodies by FACS 10-G6-C4-B2 and 30-C7-C11-D4 were selected for humanization and PTM optimization. The affinity of the humanized candidates and optimized PTM sequences was evaluated by FACS.

[0285] The results are shown in Figures 10 and 11. All sequences showed similar affinity to the parent antibody.

[0286] 9.2 Protein-based affinity testing with Biacore (ChemPartner) Test conditions: Analyte: B7H3. Running buffer: HBS-EP+. Flow rate: 30 μL / min. Supplement: Ab, 10 μL / min for 60 sec. Injection of serially diluted B7H3. Contact time 180 sec, dissociation time 400 sec. Regeneration: pH 1.5 Gly, 30 μL / min for 30 sec. Method: Multiple cycle kinetic / affinity with capture. Machine model: Biacore 8K (GE). Analysis temperature: 25°C.

[0287] The results are shown in Table 14.

[0288] [Table 14]

[0289] 9.3 In vivo ADC therapeutic potential testing of humanized 10-G6-C4-B2 antibody The in vivo ADC therapeutic potential of the humanized 10-G6-C4-B2 antibody was evaluated. Antibody conjugates with VC-MMAE were constructed at ChemPartner. A series of VC-MMAE conjugated antibodies were obtained, the details of which are shown in Table 15.

[0290] [Table 15]

[0291] Calu-6 tumor cells (5 × 10 cells) in 0.1 ml of PBS were injected into the right front flank region of each Balb / c nude mouse for the Calu-6 study for tumor development. 6 The average tumor size was approximately 122 mm 3 Randomization begins when the IL-16 expression level is reached. Sixty mice were enrolled in this study. The date of randomization is designated as day 0, and dosing begins on day 0.

[0292] The therapeutic efficacy of the test substance in treating subcutaneous human lung cancer Calu-6 in Balb / c nude mice was investigated in this study. No obvious weight loss, mortality or toxic reactions were observed with the designed dosing regimen during the efficacy study.

[0293] The results are shown in Figure 12 and Table 16. On day 26, nearly all of the test substances at 3 mg / kg as single agents each show significant antitumor effects against the Calu-6 model in Balb / c nude mice.

[0294] [Table 16]

Claims

1. rr) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:9, SEQ ID NO:374 and SEQ ID NO:375, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:376, SEQ ID NO:13 and SEQ ID NO:14; ss) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 41, SEQ ID NO: 42 and SEQ ID NO: 43, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 377, SEQ ID NO: 45 and SEQ ID NO: 46; a) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:4, SEQ ID NO:5 and SEQ ID NO:6; b) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:9, SEQ ID NO:10 and SEQ ID NO:11, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:12, SEQ ID NO:13 and SEQ ID NO:14; c) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 17, SEQ ID NO: 18 and SEQ ID NO: 19, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 20, SEQ ID NO: 21 and SEQ ID NO: 22; d) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:25, SEQ ID NO:26 and SEQ ID NO:27, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:28, SEQ ID NO:29 and SEQ ID NO:30; e) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 33, SEQ ID NO: 34 and SEQ ID NO: 35, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 36, SEQ ID NO: 37 and SEQ ID NO: 38; f) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 41, SEQ ID NO: 42 and SEQ ID NO: 43, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 44, SEQ ID NO: 45 and SEQ ID NO: 46; g) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 49, SEQ ID NO: 50 and SEQ ID NO: 51 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 52, SEQ ID NO: 53 and SEQ ID NO: 54; h) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:57, SEQ ID NO:58 and SEQ ID NO:59, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:60, SEQ ID NO:61 and SEQ ID NO:62; i) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:65, SEQ ID NO:66 and SEQ ID NO:67, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:68, SEQ ID NO:69 and SEQ ID NO:70; j) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:73, SEQ ID NO:74 and SEQ ID NO:75, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:76, SEQ ID NO:77 and SEQ ID NO:78; k) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:81, SEQ ID NO:82 and SEQ ID NO:83, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:84, SEQ ID NO:85 and SEQ ID NO:86; l) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:89, SEQ ID NO:90 and SEQ ID NO:91 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:92, SEQ ID NO:93 and SEQ ID NO:94; m) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 97, SEQ ID NO: 98 and SEQ ID NO: 99, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 100, SEQ ID NO: 101 and SEQ ID NO: 102; n) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 105, SEQ ID NO: 106 and SEQ ID NO: 107, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 108, SEQ ID NO: 109 and SEQ ID NO: 110; o) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 113, SEQ ID NO: 114 and SEQ ID NO: 115, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 116, SEQ ID NO: 117 and SEQ ID NO: 118; p) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 121, SEQ ID NO: 122 and SEQ ID NO: 123, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 124, SEQ ID NO: 125 and SEQ ID NO: 126; q) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 129, SEQ ID NO: 130 and SEQ ID NO: 131 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 132, SEQ ID NO: 133 and SEQ ID NO: 134; r) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 137, SEQ ID NO: 138 and SEQ ID NO: 139, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 140, SEQ ID NO: 141 and SEQ ID NO: 142; s) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 145, SEQ ID NO: 146 and SEQ ID NO: 147, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 148, SEQ ID NO: 149 and SEQ ID NO: 150; t) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 153, SEQ ID NO: 154 and SEQ ID NO: 155, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 156, SEQ ID NO: 157 and SEQ ID NO: 158; u) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 161, SEQ ID NO: 162 and SEQ ID NO: 163, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 164, SEQ ID NO: 165 and SEQ ID NO: 166; v) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 169, SEQ ID NO: 170 and SEQ ID NO: 171 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 172, SEQ ID NO: 173 and SEQ ID NO: 174; w) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 177, SEQ ID NO: 178 and SEQ ID NO: 179, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 180, SEQ ID NO: 181 and SEQ ID NO: 182; x) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 185, SEQ ID NO: 186 and SEQ ID NO: 187, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 188, SEQ ID NO: 189 and SEQ ID NO: 190; y) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 193, SEQ ID NO: 194 and SEQ ID NO: 195, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 196, SEQ ID NO: 197 and SEQ ID NO: 198; z) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:201, SEQ ID NO:202 and SEQ ID NO:203, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:204, SEQ ID NO:205 and SEQ ID NO:206; aa) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 209, SEQ ID NO: 210 and SEQ ID NO: 211 and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 212, SEQ ID NO: 213 and SEQ ID NO: 214; bb) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 217, SEQ ID NO: 218 and SEQ ID NO: 219, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 220, SEQ ID NO: 221 and SEQ ID NO: 222; cc) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:225, SEQ ID NO:226 and SEQ ID NO:227, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:228, SEQ ID NO:229 and SEQ ID NO:230; dd) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 233, SEQ ID NO: 234 and SEQ ID NO: 235, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 236, SEQ ID NO: 237 and SEQ ID NO: 238; ee) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:241, SEQ ID NO:242 and SEQ ID NO:243, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:244, SEQ ID NO:245 and SEQ ID NO:246; ff) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 249, SEQ ID NO: 250 and SEQ ID NO: 251 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 252, SEQ ID NO: 253 and SEQ ID NO: 254; gg) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:257, SEQ ID NO:258 and SEQ ID NO:259, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:260, SEQ ID NO:261 and SEQ ID NO:262; hh) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:265, SEQ ID NO:266 and SEQ ID NO:267, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:268, SEQ ID NO:269 and SEQ ID NO:270; ii) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:273, SEQ ID NO:274 and SEQ ID NO:275, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:276, SEQ ID NO:277 and SEQ ID NO:278; jj) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:281, SEQ ID NO:282 and SEQ ID NO:283, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:284, SEQ ID NO:285 and SEQ ID NO:286; kk) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:289, SEQ ID NO:290 and SEQ ID NO:291, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:292, SEQ ID NO:293 and SEQ ID NO:294; ll) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 297, SEQ ID NO: 298 and SEQ ID NO: 299, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 300, SEQ ID NO: 301 and SEQ ID NO: 302; mm) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 305, SEQ ID NO: 306 and SEQ ID NO: 307, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 308, SEQ ID NO: 309 and SEQ ID NO: 310; nn) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 313, SEQ ID NO: 314 and SEQ ID NO: 315, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 316, SEQ ID NO: 317 and SEQ ID NO: 318; oo) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 321, SEQ ID NO: 322 and SEQ ID NO: 323, and a light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 324, SEQ ID NO: 325 and SEQ ID NO: 326; pp) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 329, SEQ ID NO: 330 and SEQ ID NO: 331 and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO: 332, SEQ ID NO: 333 and SEQ ID NO: 334; or qq) a heavy chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:337, SEQ ID NO:338 and SEQ ID NO:339, and a kappa light chain variable region comprising one, two or three CDR sequences selected from SEQ ID NO:340, SEQ ID NO:341 and SEQ ID NO:

342. An antibody or antigen-binding fragment thereof comprising:

2. 2. The antibody or antigen-binding fragment thereof of claim 1, comprising a heavy chain variable region selected from the group consisting of SEQ ID NO:7, SEQ ID NO:15, SEQ ID NO:23, SEQ ID NO:31, SEQ ID NO:39, SEQ ID NO:47, SEQ ID NO:55, SEQ ID NO:63, SEQ ID NO:71, SEQ ID NO:79, SEQ ID NO:87, SEQ ID NO:95, SEQ ID NO:103, SEQ ID NO:111, SEQ ID NO:119, SEQ ID NO:127, SEQ ID NO:135, SEQ ID NO:143, SEQ ID NO:151, SEQ ID NO:159, SEQ ID NO:167, SEQ ID NO:175, SEQ ID NO:183, SEQ ID NO:191, SEQ ID NO:199, SEQ ID NO:207, SEQ ID NO:215, SEQ ID NO:223, SEQ ID NO:231, SEQ ID NO:239, SEQ ID NO:247, SEQ ID NO:255, SEQ ID NO:263, SEQ ID NO:271, SEQ ID NO:279, SEQ ID NO:287, SEQ ID NO:295, SEQ ID NO:303, SEQ ID NO:311, SEQ ID NO:319, SEQ ID NO:327, SEQ ID NO:335, SEQ ID NO:343, SEQ ID NO:347, and SEQ ID NO:349, and homologous sequences having at least 80% sequence identity thereto.

3. 2. The antibody or antigen-binding fragment thereof of claim 1, comprising a light chain variable region selected from the group consisting of SEQ ID NO:8, SEQ ID NO:16, SEQ ID NO:24, SEQ ID NO:32, SEQ ID NO:40, SEQ ID NO:48, SEQ ID NO:56, SEQ ID NO:64, SEQ ID NO:72, SEQ ID NO:80, SEQ ID NO:88, SEQ ID NO:96, SEQ ID NO:104, SEQ ID NO:112, SEQ ID NO:120, SEQ ID NO:128, SEQ ID NO:136, SEQ ID NO:144, SEQ ID NO:152, SEQ ID NO:160, SEQ ID NO:168, SEQ ID NO:1756, SEQ ID NO:184, SEQ ID NO:192, SEQ ID NO:200, SEQ ID NO:208, SEQ ID NO:216, SEQ ID NO:224, SEQ ID NO:232, SEQ ID NO:240, SEQ ID NO:248, SEQ ID NO:256, SEQ ID NO:264, SEQ ID NO:272, SEQ ID NO:280, SEQ ID NO:288, SEQ ID NO:296, SEQ ID NO:304, SEQ ID NO:312, SEQ ID NO:320, SEQ ID NO:328, SEQ ID NO:336, SEQ ID NO:344, SEQ ID NO:348, and SEQ ID NO:350, and homologous sequences having at least 80% sequence identity thereto.

4. a) a heavy chain variable region comprising SEQ ID NO:7 and a light chain variable region comprising SEQ ID NO:8; b) a heavy chain variable region comprising SEQ ID NO: 15 and a light chain variable region comprising SEQ ID NO: 16; c) a heavy chain variable region comprising SEQ ID NO:23 and a light chain variable region comprising SEQ ID NO:24; d) a heavy chain variable region comprising SEQ ID NO:31 and a light chain variable region comprising SEQ ID NO:32; e) a heavy chain variable region comprising SEQ ID NO: 39 and a light chain variable region comprising SEQ ID NO: 40; f) a heavy chain variable region comprising SEQ ID NO:47 and a light chain variable region comprising SEQ ID NO:48; g) a heavy chain variable region comprising SEQ ID NO:55 and a light chain variable region comprising SEQ ID NO:56; h) a heavy chain variable region comprising SEQ ID NO:63 and a light chain variable region comprising SEQ ID NO:64; i) a heavy chain variable region comprising SEQ ID NO: 71 and a light chain variable region comprising SEQ ID NO: 72; j) a heavy chain variable region comprising SEQ ID NO: 79 and a light chain variable region comprising SEQ ID NO: 80; k) a heavy chain variable region comprising SEQ ID NO:87 and a light chain variable region comprising SEQ ID NO:88; l) a heavy chain variable region comprising SEQ ID NO: 95 and a light chain variable region comprising SEQ ID NO: 96; m) a heavy chain variable region comprising SEQ ID NO: 103 and a light chain variable region comprising SEQ ID NO: 104; n) a heavy chain variable region comprising SEQ ID NO: 111 and a light chain variable region comprising SEQ ID NO: 112; o) a heavy chain variable region comprising SEQ ID NO: 119 and a light chain variable region comprising SEQ ID NO: 120; p) a heavy chain variable region comprising SEQ ID NO: 127 and a light chain variable region comprising SEQ ID NO: 128; q) a heavy chain variable region comprising SEQ ID NO: 135 and a light chain variable region comprising SEQ ID NO: 136; r) a heavy chain variable region comprising SEQ ID NO: 143 and a light chain variable region comprising SEQ ID NO: 144; s) a heavy chain variable region comprising SEQ ID NO: 151 and a light chain variable region comprising SEQ ID NO: 152; t) a heavy chain variable region comprising SEQ ID NO: 159 and a light chain variable region comprising SEQ ID NO: 160; u) a heavy chain variable region comprising SEQ ID NO: 167 and a light chain variable region comprising SEQ ID NO: 168; v) a heavy chain variable region comprising SEQ ID NO: 175 and a light chain variable region comprising SEQ ID NO: 176; w) a heavy chain variable region comprising SEQ ID NO: 183 and a light chain variable region comprising SEQ ID NO: 184; x) a heavy chain variable region comprising SEQ ID NO: 191 and a light chain variable region comprising SEQ ID NO: 192; y) a heavy chain variable region comprising SEQ ID NO: 199 and a light chain variable region comprising SEQ ID NO: 200; z) a heavy chain variable region comprising SEQ ID NO: 207 and a light chain variable region comprising SEQ ID NO: 208; aa) a heavy chain variable region comprising SEQ ID NO: 215 and a light chain variable region comprising SEQ ID NO: 216; bb) a heavy chain variable region comprising SEQ ID NO: 223 and a light chain variable region comprising SEQ ID NO: 224; cc) a heavy chain variable region comprising SEQ ID NO: 231 and a light chain variable region comprising SEQ ID NO: 232; dd) a heavy chain variable region comprising SEQ ID NO: 239 and a light chain variable region comprising SEQ ID NO: 240; ee) a heavy chain variable region comprising SEQ ID NO: 247 and a light chain variable region comprising SEQ ID NO: 248; ff) a heavy chain variable region comprising SEQ ID NO: 255 and a light chain variable region comprising SEQ ID NO: 256; gg) a heavy chain variable region comprising SEQ ID NO: 263 and a light chain variable region comprising SEQ ID NO: 264; hh) a heavy chain variable region comprising SEQ ID NO: 271 and a light chain variable region comprising SEQ ID NO: 272; ii) a heavy chain variable region comprising SEQ ID NO:279 and a light chain variable region comprising SEQ ID NO:280; jj) a heavy chain variable region comprising SEQ ID NO:287 and a light chain variable region comprising SEQ ID NO:288; kk) a heavy chain variable region comprising SEQ ID NO:295 and a light chain variable region comprising SEQ ID NO:296; ll) a heavy chain variable region comprising SEQ ID NO: 303 and a light chain variable region comprising SEQ ID NO: 304; mm) a heavy chain variable region comprising SEQ ID NO:311 and a light chain variable region comprising SEQ ID NO:312; nn) a heavy chain variable region comprising SEQ ID NO: 319 and a light chain variable region comprising SEQ ID NO: 320; oo) a heavy chain variable region comprising SEQ ID NO: 327 and a light chain variable region comprising SEQ ID NO: 328; pp) a heavy chain variable region comprising SEQ ID NO: 335 and a light chain variable region comprising SEQ ID NO: 336; qq) a heavy chain variable region comprising SEQ ID NO: 343 and a light chain variable region comprising SEQ ID NO: 344; rr) a heavy chain variable region comprising SEQ ID NO: 347 and a light chain variable region comprising SEQ ID NO: 348; or ss) a heavy chain variable region comprising SEQ ID NO: 349 and a light chain variable region comprising SEQ ID NO: 350 The antibody or antigen-binding fragment thereof of claim 1 .

5. SEQ ID NO: 378 (EVQLVESGGGLXQPGXSLRLSCXTSGFTLSDYYMSWVRQXPGKGLEWVXFMRNKANXYTTEYSASVRGRFTISRDTSKSXIYLQMNSLXXEDTAVYYCVRDRXGRPFAYWGQGTLVTVSS), wherein X at position i (i=12, 16, 23, 40, 49, 57, 80, 89, 90 and 103) of SEQ ID NO: 378 is X Ｈｉ It is called X Ｈ１２ is V or I, and XH １６ is G or R, and X Ｈ２３ is A or T, and X Ｈ４０ is A or P, and X Ｈ４９ is G or S, and X Ｈ５７ is A or G, and X Ｈ８０ is I or T, and X Ｈ８９ is R or K, and X Ｈ９０ is A or T, and X Ｈ１０３ is D or E, and SEQ ID NO:379 (DIXMTQSPXSLXXXXGXXXXIXCKSSQSLLNXINQKNFLTWYXQKPGXXPXLLIYWASTRESGVPXRFSGSGSGTDFTLXISXXXXEDLXXYYCQNDYTYPLTFGQGTKLEIK), wherein X at position i of SEQ ID NO:379 (i=3, 9, 12, 13, 14, 15, 17, 18, 19, 20, 22, 32, 43, 48, 49, 51, 66, 80, 83, 84, 85, 86, 90, and 91) is X Ｌｉ It is called X Ｌ３ is V or Q, and X Ｌ９ is D, L or S; X Ｌ１２ is A, S or P, and X Ｌ１３ is A or V, and X Ｌ１４ is S or T, and X Ｌ１５ is L, V or P; X Ｌ１７ is D or E, and X Ｌ１８ is R or P, and X Ｌ１９ is A or V, and X Ｌ２０ is S or T, and X Ｌ２２ is N, T or S, and X Ｌ３２ is A or S, and X Ｌ４３ is Q or L, and X Ｌ４８ is Q or K, and X Ｌ４９ is A, P or S, and X Ｌ５１ is K or Q, and X Ｌ６６ is S or D, and X Ｌ８０ is K or T, and X Ｌ８３ is R or S, and X Ｌ８４ is L or V, and X Ｌ８５ is Q or E, and X Ｌ８６ is A or P, and X Ｌ９０ is A or G, and X Ｌ９１ The antibody or antigen-binding fragment thereof of claim 1 , comprising a light chain variable region in which is T or V.

6. SEQ ID NO: 380 (QVQLQESGPGLVKPSXTLSLTCXVXGYSITSDYAWNWIRQXPGKGLEWIGYISHSGSTSYNPSLKSRVTISRDTSKNQFSLKLSSVTAADTAVYYCARSLGRRWYFDVWGQGTTVTVSS), wherein X at position i (i=16, 23, 25 and 41) of SEQ ID NO: 380 is X Ｈｉ It is called X Ｈ１６ is E or Q, and X Ｈ２３ is A or T, and X Ｈ２５ is S or Y, and X Ｈ４１ is H or P; and SEQ ID NO: 381 (DIXMTQSPXSLXXXXGXXXXIXCKSSQSLLXSSTQKNYLAWYXQKPGXXPXLLIYFASTRDSGVPXRFSGSGSGTDFTLXISXXXXEDLXXYFCQQHYIIPFTFGQGTKLEIK), wherein X at position i (i=3, 9, 12, 13, 14, 15, 17, 18, 19, 20, 22, 31, 43, 48, 49, 51, 66, 80, 83, 84, 85, 86, 90 and 91) of SEQ ID NO: 381 is X Ｌｉ It is called X Ｌ３ is V or Q, and X Ｌ９ is D, L or S; X Ｌ１２ is A, S or P, and X Ｌ１３ is A or V, and X Ｌ１４ is S or T, and X Ｌ１５ is L, V or P; X Ｌ１７ is D or E, and X Ｌ１８ is R or P, and X Ｌ１９ is A or V, and X Ｌ２０ is S or T, and X Ｌ２２ is N, T or S, and X Ｌ３１ is N or Q, and X Ｌ４３ is Q or L, and X Ｌ４８ is Q or K, and X Ｌ４９ is A, P or S, and X Ｌ５１ is K or Q, and X Ｌ６６ is S or D, and X Ｌ８０ is K or T, and X Ｌ８３ is R or S, and X Ｌ８４ is L or V, and X Ｌ８５ is Q or E, and X Ｌ８６ is A or P, and X Ｌ９０ is A or G, and X Ｌ９１ is T or V.

7. The antibody or antigen-binding fragment thereof described in claim 1, comprising a heavy chain variable region comprising one, two or three CDR sequences shown as SEQ ID NO:9, SEQ ID NO:10 or 374 (MRNKANAYTT) and SEQ ID NO:11 or 375 (VRDREGRPFAY), respectively, and a kappa light chain variable region comprising one, two or three CDR sequences shown as SEQ ID NO:12 or 376 (QSLLNAINQKNF), SEQ ID NO:13 and SEQ ID NO:14, respectively.

8. The antibody or antigen-binding fragment thereof of claim 1, comprising a heavy chain variable region comprising one, two or three CDR sequences shown as SEQ ID NO:41, SEQ ID NO:42 and SEQ ID NO:43, respectively, and a kappa light chain variable region comprising one, two or three CDR sequences shown as SEQ ID NO:44 or 377 (QSLLQSSTQKNY), SEQ ID NO:45 and SEQ ID NO:46, respectively.

9. The antibody or antigen-binding fragment thereof of claim 1, comprising a heavy chain variable region comprising a sequence selected from SEQ ID NOs: 351, 353, 355, 357, 358, 360, 362 and 364, and a light chain variable region comprising a sequence selected from SEQ ID NOs: 352, 354, 356, 359, 361 and 363.

10. An antibody or antigen-binding fragment thereof described in claim 1, comprising a heavy chain variable region comprising an array selected from SEQ ID NOs: 365, 367 and 370, and a light chain variable region comprising an array selected from SEQ ID NOs: 366, 368, 369, 371, 372 and 373.

11. 2. The antibody or antigen-binding fragment thereof of claim 1, further comprising an immunoglobulin constant region, optionally a human Ig constant region, or optionally a human IgG constant region.

12. Fab, Fab', F(ab') ２ , Fd, Fv fragment, disulfide stabilized Fv fragment (dsFv), (dsFv) ２ 2. The antibody or antigen-binding fragment thereof of claim 1, which is a single chain antibody molecule (scFv), a camelized single domain antibody, a nanobody, a domain antibody and a bivalent domain antibody.

13. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment is linked to one or more conjugates, and optionally the conjugates are covalently bonded either directly or via a linker.

14. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof described in claim 1 and a pharma- ceutically acceptable carrier.

15. An isolated polynucleotide encoding the antibody or antigen-binding fragment thereof of claim 1.

16. A vector comprising the isolated polynucleotide of claim 15.

17. A host cell comprising the vector of claim 16.

18. A method for treating a disease or condition in a subject that would benefit from modulation of CD276 activity, comprising administering to the subject a therapeutically effective amount of an antibody or antigen-binding fragment thereof described in claim 1 or a pharmaceutical composition described in claim 14.

19. 20. The method of claim 18, wherein the disease or condition is cancer, an adaptive immune disease, an autoimmune disease, an inflammatory disease or an infectious disease.

20. A method for regulating CD276 activity in a cell expressing CD276, comprising exposing the cell expressing CD276 to an antibody or antigen-binding fragment thereof described in claim 1.

Images