Anti-B7-H3/CD276 (Extracellular region) Antibody

B7 homolog 3 (B7-H3, CD276) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses. B7-H3 is a membrane protein with an extracellular region that includes two Ig-like V-type domains and two IgG-like C2-type domains, and a short intracellular domain. B7-H3 is a regulatory molecule for immune reactions, such as T cell proliferation and IFN-γ production. In colon cancers, B7-H3 inhibits T-cell cytotoxicity, and blocking B7-H3 function enhances T-cell cytotoxicity toward cancer cells. B7-H3 is expressed by antigen presenting cells, activated T cells, and a few normal tissues, including placenta and prostate. In cancer, B7-H3 is expressed in various tumor types including prostate, breast, colon, lung, and gastric cancers. The B7-H3 expression level correlates with tumor growth, invasion, metastasis, malignant stage, and recurrence rate. The inhibition or blockade of B7-H3 function could be an important immunotherapeutic approach for several types of cancer