A Structural Change in Butyrophilin upon Phosphoantigen Binding Underlies Phosphoantigen-Mediated V?9V?2 T Cell Activation (Immunity)

V?9V?2 T cells sense tumor and microbial metabolites without MHC restriction. Yang et al. used a multifaceted approach to show how the highly potent microbial HMBPP binds to BTN3A1 and triggers inside-out signaling to activate V?9V?2 T cells. This study will have implications in emerging clinical applications of allogeneic V?9V?2 T cells.