Long-lived epithelial immunity by tissue-resident memory T (T RM ) cells in the absence of persisting local antigen presentation

Although circulating memory T cells provide enhanced protection against pathogen challenge, they often fail to do so if infection is localized to peripheral or extralymphoid compartments. In those cases, it is T cells already resident at the site of virus challenge that offer superior immune protection. These tissue-resident memory T (T(RM)) cells are identified by their expression of the α-chain from the integrin α(E)(CD103)β(7), and can exist in disequilibrium with the blood, remaining in the local environment long after peripheral infections subside. In this study, we demonstrate that long-lived intraepithelial CD103(+)CD8(+) T(RM) cells can be generated in the absence of in situ antigen recognition. Local…