BTLA

B- and T-lymphocyte attenuator is a is_associated_with::protein that in humans is encoded by the BTLA is_associated_with::gene. BTLA has also been designated as CD272 (is_associated_with::cluster of differentiation 272).

Function
BTLA expression is induced during activation of is_associated_with::T cells, and BTLA remains expressed on Th1 cells but not Th2 cells. Like PD1 and is_associated_with::CTLA4, BTLA interacts with a B7 homolog, B7H4. However, unlike PD-1 and CTLA-4, BTLA displays T-Cell inhibition via interaction with tumor necrosis family receptors (TNF-R), not just the B7 family of cell surface receptors. BTLA is a ligand for tumour necrosis factor (receptor) superfamily, member 14 (is_associated_with::TNFRSF14), also known as herpes virus entry mediator (HVEM). BTLA-HVEM complexes negatively regulate T-cell immune responses.

Clinical significance
BTLA activation inhibits the function of human is_associated_with::CD8+ cancer-specific T cells.