Anti-hCTLA4 isotype family
The anti-hCTLA4 isotype family features the variable region of ipilimumab. Ipilimumab is a fully human IgG1 monoclonal antibody that targets CTLA-4 (also known as CD152), a negative regulator of T cell activation. By binding CTLA-4, ipilimumab inhibits negative signals that physiologically downregulate T cell activation and exerts its therapeutic activity by upregulating the antitumor activity of T lymphocytes. In addition, Ipilimumab induces antibody-dependent cell-mediated cytotoxicity (ADCC) and TNF-a production. Ipilimumab has been approved by the FDA for the treatment of unresectable or metastatic melanoma. Ipilimumab is undergoing clinical trials for other types of cancers, including lung cancer.
Antibodies of the anti-hCTLA4 isotype family have been generated by recombinant DNA technology. They have been produced in CHO cells and purified by different types of affinity chromatography: protein G for IgG1 and IgG4 and peptide M for IgA2.