CTLA-4: Difference between revisions

'''CTLA4''' or '''Cytotoxic T-Lymphocyte Associated protein 4''' or '''CD152''' is a member of the immunoglobulin superfamily that is expressed by activated T cells and transmits an inhibitory signal to T cells. CTLA4 is homologous to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells<ref>PMID:32185705</ref>. CTLA-4 binds CD80 and CD86 with greater affinity and avidity than CD28 thus enabling it to outcompete CD28 for its ligands. CTLA4 transmits an inhibitory signal to T cells,[10][11][12][7] whereas CD28 transmits a stimulatory signal.[13][14] CTLA4 is also found in regulatory T cells (Tregs) and contributes to their inhibitory function. T cell activation through the T cell receptor and CD28 leads to increased expression of CTLA-4.