Figure 3.

BTLA binds HVEM and UL144 in trans and in cis using an overlapping epitope. A and B, 293T cells transfected with BTLA alone or together with HVEM or human CMV UL144 were stained with the indicated concentrations of HVEM-Fc (A) or human CMV UL144-Fc (B). C and D, 293T cells transfected with HVEM (C) or human CMV UL144 (D) alone or together with wild-type, R42D, or E57A BTLA were stained with the indicated concentrations of BTLA-Fc. Graphs show specific MFI for Fc binding to co-expressed cells. E and F, BJAB cells transduced with BTLA were incubated with the indicated concentrations of anti-BTLA prior to staining with 20 μg/ml of HVEM-Fc (E) or human CMV UL144-Fc (F). Graphs show curves of antibody blockade of HVEM and UL144-Fc cell binding.