Vγ9+Vδ2+Tcell-mediated purging ofListeria monocytogenes-infected epithelial cells requires butyrophilin 3A genes

Abstract

AbstractIntracellular bacteria produce antigens, which serve as potent activators of γδ T cells. Phosphoantigens are presented via a complex of Butyrophilins (BTN) to signal infection to human Vγ9+Vδ2+ T cells. Here, we established an in vitro system allowing for studies of Vγ9+Vδ2+ T cell activity in coculture with epithelial cells infected with the intracellular bacterial pathogenListeria monocytogenes. We report that the Vγ9+Vδ2+ 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 Vγ9+Vδ2+ 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 Vγ9+Vδ2+ T cell effector function against L. monocytogenes-infected epithelia.