Summary Dendritic cells (DCs) phagocytose, process and present bacterial-antigens to T lymphocytes to trigger adaptive immunity. In vivo, bacteria can also be found inside T lymphocytes. However, T cells are refractory to direct bacterial infection, leaving the mechanisms by which bacteria invade T cells unclear. We show that T cells take up bacteria from infected DCs by the process of trans-infection, which requires direct contact between the two cells and is enhanced by antigen recognition. Prior to transfer, bacteria localize to the immunological synapse, an intimate DC/T cell contact structure that activates T cells. Strikingly, T cells efficiently eliminate the trans-infecting bacteria within the first hours after infection. Trans-infected T cells produced high levels of pro-inflammatory cytokines and were able to protect mice from bacterial challenge following adoptive transfer. Thus, T lymphocytes can capture and kill bacteria in a manner reminiscent of innate immunity.