Cytotoxic T-lymphocyte antigen 4 (CTLA-4), also named CD152, is a member of the immunoglobulin superfamily. CTLA-4 is expressed mainly on activated T cells, acts as a vital restraining regulator of T-cell proliferation and activation, and induces Fas-independent apoptosis of activated T cells to further inhibit immune function of T-cell. Blocking CTLA-4 function and enhancing T cell activation, several different types of malignant neoplasms in tumor-transplanted mice were inhibited or cured, and owned long-lasting antitumor immunity. It suggests that CTLA-4 plays an important role in carcinogenesis. CTLA-4 is an inducible receptor expressed by T cells that ligates the B7 family of molecules (primarily CD80 and CD86) on antigen-presenting cells. CTLA-4 activation suppresses proliferation and function of T-lymphocytes, and an antibody to CTLA-4 abrogates the CTLA-4 signaling pathway. Although objective responses were observed in some patients with ovarian, prostate and kidney cancer, the effect of CTLA-4 antibody has not translated into improved overall long-term survival.
Tang W, Qiu H, Jiang H, et al. Lack of Association between Cytotoxic T-lymphocyte Antigen 4 (CTLA-4) -1722T/C (rs733618) Polymorphism and Cancer Risk: From a Case-Control Study to a Meta-Analysis. Wang J, ed. PLoS ONE. 2014;9(4):e94039.