Keeping T cell memories in mind

Abstract

The mammalian central nervous system (CNS) contains a vibrant community of resident adaptive immune cells at homeostasis. Among these are memory CD8⁺ and CD4⁺ T cells, which reside in the CNS in the settings of health, aging, and neurological disease. These T cells commonly exhibit a tissue-resident memory (T_RM) phenotype, suggesting that they are antigen-experienced and remain separate from the circulation. Despite these characterizations, T cell surveillance of the CNS has only recently been studied through the lens of T_RM immunology. In this Review, we outline emerging concepts of CNS T_RM generation, localization, maintenance, function, and specificity. In this way, we hope to highlight roles of CNS T_RM in health and disease to inform future studies of adaptive neuroimmunity.

Keywords: adaptive immunity; central nervous system; memory CD4 T cell; memory CD8 T cell; neuroimmune interactions; tissue resident memory T cell.