Formation and Maintenance of Tissue Resident Memory CD8+ T Cells after Viral Infection

Tissue resident memory (T_RM) CD8 T cells comprise a memory population that forms in peripheral, non-lymphoid tissues after an infection that does not recirculate into the bloodstream or other tissues. T_RM cells often recognize conserved peptide epitopes shared among different strains of a pathogen and so offer a protective role upon secondary encounter with the same or related pathogens. Several recent studies have begun to shed light on the intrinsic and extrinsic factors regulating T_RM. In addition, work is being done to understand how canonical "markers" of T_RM actually affect the function of these cells. Many of these markers regulate the generation or persistence of these T_RM cells, an important point of study due to the differences in persistence of T_RM between tissues, which may impact future vaccine development to cater towards these important differences. In this review, we will discuss recent advances in T_RM biology that may lead to strategies designed to promote this important protective immune subset.