B7 homolog 3 (CD276) (B7-H3)

B7 homolog 3 (B7-H3), also known as CD276, is a type I transmembrane glycoprotein and a member of the B7 family of immunomodulatory proteins. It was initially identified as a 'novel tumor-associated surface antigen' (notably the 8H9 antigen) due to its high expression across a broad spectrum of human solid tumors, including neuroblastoma, sarcomas, and various carcinomas, while maintaining very restricted expression in normal tissues. B7-H3 plays a dual role in the immune system, primarily acting as a checkpoint molecule that inhibits T-cell and natural killer (NK) cell-mediated anti-tumor responses, thereby facilitating immune evasion. In addition to its immunomodulatory functions, B7-H3 is involved in promoting tumor cell migration, invasion, and angiogenesis, which are associated with poor clinical prognosis. Therapeutic strategies targeting B7-H3 are currently in development, including monoclonal antibodies like omburtamab, antibody-drug conjugates (ADCs) such as ifinatamab deruxtecan (DS-7300), and chimeric antigen receptor (CAR) T-cell therapies.

Other names

CD276B7 homolog 34Ig-B7-H38H9 antigengp58