Vgamma9+Vdelta2+Tcell-mediated purging of Listeria monocytogenes-infected epithelial cells requires butyrophilin 3A genes
Intracellular bacteria produce antigens, which serve as potent activators of {gamma}{delta} T cells. Phosphoantigens are presented via a complex of Butyrophilins (BTN) to signal infection to human V{gamma}9+V{delta}2+ T cells. Here, we established an in vitro system allowing for studies of V{gamma}9+V{delta}2+ T cell activity in coculture with epithelial cells infected with the intracellular bacterial pathogen Listeria monocytogenes. We report that the V{gamma}9+V{delta}2+ T cells efficiently purge such cultures from infected cells. This effector function requires the expression of members of the BTN3A family on epithelial cells. Specifically, the BTN3A1 and BTN3A3 are redundant in their ability to present antigen to V{gamma}9+V{delta}2+ T cells. Since BTN3A1 is the only BTN3A associated with phosphoantigen presentation our study suggests that BTN3A3 may present different classes of antigens to mediate V{gamma}9+V{delta}2+ T cell effector function against L. monocytogenes-infected epithelia.