BTLA

B and T cell lymphocyte attenuator (BTLA; CD272) is an inhibitory receptor that belongs to the B7-CD28 family. BTLA is structurally and functionally related to CTLA-4 and PD-1 and can be identified on most lymphocytes, such as T and B lymphocytes, macrophages, dendritic cells, and nature killer (NK) cells. The BTLA ligand, herpesvirus entry mediator (HVEM, also called TNFRSF14), is a member of the tumor necrosis factor receptor (TNFR) superfamily. Ligation of BTLA by HVEM induces tyrosine phosphorylation of ITIM in BTLA and subsequent recruitment of the protein tyrosine phosphatases SHP-1/SHP-2, and then exerts direct negative effects on the proliferation and activation of B and T cells. BTLA participates in numerous physiopathological processes, such as tumor, inflammatory diseases, autoimmune diseases, infectious diseases, and transplantation rejection.