Immune response to Salmonella: Location, location, location?

Successful immunity against Salmonella infections is dependent on the generation of CD4(+) T helper cells and to a lesser extent on antibody production and CD8(+) T cells. The cells within the lymphatic tissue of the gut are likely to be central for the orchestration of a proper and rapid response. The anatomical restriction of the pathogen may also determine the distribution of effector cells. In this issue of Immunity, McSorley et al. address both of these processes using identifiable CD4 T cells that are specific for Salmonella typhimurium. Such cells localize to the Peyer's patches of the small intestine when the bacteria are delivered orally.