CD276 (Cluster of Differentiation 276) is a human protein encoded by the CD276 gene and belongs to the immunoglobulin superfamily. The transcript of B7-H3 is ubiquitously expressed in normal tissues and solid tumors, the protein is preferentially expressed only in tumor tissues. B7H3 is expressed on immune cells (such as antigen-presenting cells or macrophages) and has inhibitory roles on T cells, contributing to tumor cell immune evasion. Importantly, B7-H3 is highly overexpressed on a wide range of human solid cancers and often correlates with both negative prognosis and poor clinical outcome in patients. Recent studies have shown that B7H3 is a crucial player in tumor growth, invasion, migration, angiogenesis and metastasis beyond the immune regulatory roles. Due to its role in immune evasion, B7-H3 has become an interesting target for new immunotherapeutic treatments. B7-H3 and PD-L1 induce an inhibitory effect on T-cells and change their microenvironment to escape the anti-tumor immune response. B7-H3 and CTLA4 may act synergistically with one another, just as B7-H3 does in the PD-1 pathway.
B-CAG-hB7-H3 MC38 binds anti-human B7-H3 antibody
Analysis of B-CAG-hB7-H3 MC38 by FACS. Flow cytometry analysis of the B-CAG-hB7-H3 MC38 was performed to assess anti-human B7-H3 Ab binding. Single live cells were gated and used for further analysis as indicated here. B-CAG-hB7-H3 MC38 binds well with enoblituzumab (in house) vs isotype control.
In vivo efficacy of anti-human B7-H3 antibody
Antitumor activity of anti-human B7-H3 antibody in B-hB7-H3 mice. (A) Anti-human B7-H3 antibody inhibited hB7-H3 MC38 tumor growth in B-hB7-H3 mice. Murine colon cancer hB7-H3 MC38 cells were subcutaneously implanted into homozygous B-hB7-H3 mice (female, 6-7 week-old, n=5). Mice were grouped according to body weight differences, and treated with anti-hB7-H3 antibody at doses and schedules in panel A. (B) Body weight changes during treatment. As shown in panel A, enoblituzumab (in house) were efficacious in controlling tumor growth in B-hB7-H3, demonstrating they provide a powerful preclinical model for in vivo evaluation of anti-human B7-H3 antibodies. Values are expressed as mean ± SEM.