CD4+ resident memory T cells dominate immunosurveillance and orchestrate local recall responses

This study examines the extent to which memory CD4+ T cells share immunosurveillance strategies with CD8+ resident memory T cells (TRM). After acute viral infection, memory CD4+ T cells predominantly used residence to survey nonlymphoid tissues, albeit not as stringently as observed for CD8+ T cells. In contrast, memory CD4+ T cells were more likely to be resident within lymphoid organs than CD8+ T cells. Migration properties of memory-phenotype CD4+ T cells in non-SPF parabionts were similar, generalizing these results to diverse infections and conditions. CD4+ and CD8+ TRM shared overlapping transcriptional signatures and location-specific features, such as granzyme B expression in the small intestine, revealing tissue-specific and migration property–specific, in addition to lineage-specific, differentiation programs. Functionally, mucosal CD4+ TRM reactivation locally triggered both chemokine expression and broad immune cell activation. Thus, residence provides a dominant mechanism for regionalizing CD4+ T cell immunity, and location enforces shared transcriptional, phenotypic, and functional properties with CD8+ T cells.

Source: The Journal of Experimental Medicine - May 5, 2019 Category: Internal Medicine Authors: Beura, L. K., Fares-Frederickson, N. J., Steinert, E. M., Scott, M. C., Thompson, E. A., Fraser, K. A., Schenkel, J. M., Vezys, V., Masopust, D. Tags: Mucosal Immunology Articles Source Type: research