B and T lymphocyte attenuator (BTLA; CD272) is a member of the Ig superfamily and is part of the checkpoint receptor family that negatively regulates immune cell activation. BTLA is mainly expressed on B cells, T cells, and dendritic cells. The natural ligand for BTLA is Tumor necrosis factor receptor superfamily member 14 (HVEM; TNFRSF14).BTLA and HVEM primarily regulate the function of T cells and antigen-presenting cells through dynamic expression on the cell surface. Binding of BTLA to its ligand not only inhibits T cell proliferation, downregulates the T cell activation marker CD25, and suppresses the production of IFN-y, IL-2, IL-4, and IL-10, but also does not induce cell apoptosis. HVEM binding to BTLA leads to downregulation of T cell activation and proliferation.The BTLA Reporter Cell Line is a luciferase reporter cell line based on the BTLA-HVEM signaling pathway. When BTLA Reporter cells are co-cultured with HVEM aAPC CHO cells, HVEM binds to BTLA, recruits SHP1, inhibits TCR signaling, thereby suppressing the expression of luciferase. By adding Anti-BTLA antibody to block BTLA-HVEM binding, TCR signaling is restored, normal expression of luciferase is achieved, and the luciferase reporter gene reading reflects the activation effect of the signaling pathway. This can be used for the functional antibody activity detection of HVEM or BTLA.
