- Peres, Newton G;
- Wang, Nancy;
- Whitney, Paul;
- Engel, Sven;
- Shreenivas, Meghanashree M;
- Comerford, Ian;
- Hocking, Dianna M;
- Erazo, Anna B;
- Förster, Irmgard;
- Kupz, Andreas;
- Gebhardt, Thomas;
- McColl, Shaun R;
- McSorley, Stephen J;
- Bedoui, Sammy;
- Strugnell, Richard A
- Editor(s): Monack, Denise M
While Salmonella enterica is seen as an archetypal facultative intracellular bacterial pathogen where protection is mediated by CD4+ T cells, identifying circulating protective cells has proved very difficult, inhibiting steps to identify key antigen specificities. Exploiting a mouse model of vaccination, we show that the spleens of C57BL/6 mice vaccinated with live-attenuated Salmonella serovar Typhimurium (S. Typhimurium) strains carried a pool of IFN-γ+ CD4+ T cells that could adoptively transfer protection, but only transiently. Circulating Salmonella-reactive CD4+ T cells expressed the liver-homing chemokine receptor CXCR6, accumulated over time in the liver and assumed phenotypic characteristics associated with tissue-associated T cells. Liver memory CD4+ T cells showed TCR selection bias and their accumulation in the liver could be inhibited by blocking CXCL16. These data showed that the circulation of CD4+ T cells mediating immunity to Salmonella is limited to a brief window after which Salmonella-specific CD4+ T cells migrate to peripheral tissues. Our observations highlight the importance of triggering tissue-specific immunity against systemic infections.