CD276 antigen (B7 homolog 3) (B7-H3)

B7-H3, also known as CD276, is a type I transmembrane glycoprotein and a member of the B7 family of immune checkpoint molecules. It is characterized by its limited expression in normal human tissues but significant overexpression in a wide range of solid tumors and the surrounding tumor microenvironment, including on tumor-associated macrophages and endothelial cells (1.1.1, 1.3.2). B7-H3 plays a complex role in the immune system, predominantly acting as a co-inhibitory molecule that suppresses T-cell proliferation and cytokine production, thereby facilitating tumor immune evasion (1.1.1, 1.3.3). Beyond its immunological functions, B7-H3 is involved in non-immunologic processes such as promoting tumor cell migration, invasion, angiogenesis, and metabolic reprogramming (1.1.2, 1.3.3). It also contributes to therapeutic resistance by activating survival pathways like JAK2/STAT3 and PI3K/AKT (1.1.2, 1.1.4). Due to its high tumor-to-normal tissue expression ratio, B7-H3 is an attractive target for various therapeutic modalities, including antibody-drug conjugates (ADCs), monoclonal antibodies, and chimeric antigen receptor (CAR) T-cell therapies (1.4.1, 1.4.2). Clinical development is currently focused on leveraging these mechanisms to treat aggressive malignancies such as small-cell lung cancer, prostate cancer, and pediatric neuroblastoma (1.4.2, 1.4.4).

Other names

CD276B7 homolog 3B7RP-24Ig-B7-H32Ig-B7-H3

Antibody-dependent cellular cytotoxicity (ADCC), antibody-drug conjugate (ADC) mediated delivery of cytotoxic payloads, chimeric antigen receptor (CAR) T-cell mediated lysis, radioimmunotherapy, and bispecific/trispecific killer cell engagement (1.1.1, 1.1.4, 1.4.1, 1.4.2).