How distinct virus-specific memory CD8 T cell subsets control respiratory virus infection
Cytomegalovirus infection induces large numbers of circulating memory CD8 T cells, while influenza virus infection induces tissue-resident memory CD8 T cells in the lung. A recent ‘Mucosal Immunology’ paper by the Oxenius group shows that both subsets equally protect against respiratory infection, albeit employing different mechanisms of activation and relocation.
Induction of memory CD8 T cells residing in peripheral tissues is of interest for T cell-based vaccines as these cells can immediately exert effector functions providing protection in case of local pathogen encounter. Different memory CD8 T cell subsets are present in peripheral tissues, but it is unclear which subset is superior in providing protection. We used influenza virus to induce predominantly tissue resident memory T cells or cytomegalovirus (MCMV) to elicit a large pool of effector-like memory cells in the lungs and determined their early protective capacity and mechanism of reactivation. Despite their different phenotype and localization in lung tissue, both memory CD8 T cell subsets provided comparable protection against a respiratory infection. While influenza-induced memory CD8 T cells respond to antigen by local proliferation, MCMV-induced memory CD8 T cells relocate from the vasculature into the tissue. Together these results bear relevance for the development of vaccines aimed at eliciting a protective memory CD8 T cell pool at mucosal sites.
Link to the publication in external page "Mucosal Immunology".