Project description:Tissue resident memory (Trm) represent a newly described memory T cell population. We have previously characterized a population of Trm that persists within the brain following acute virus infection. Although capable of providing marked protection against a subsequent local challenge, brain Trm do not undergo recall expansion following dissociation from the tissue. Furthermore, these Trm do not depend on the same survival factors as the circulating memory T cell pool as assessed either in vivo or in vitro. To gain greater insight into this population of cells we compared the gene-expression profiles of Trm isolated from the brain to circulating memory T cells isolated from the spleen following an acute virus infection. Trm displayed altered expression of genes involved in chemotaxis, expressed a distinct set of transcription factors and overexpressed several inhibitory receptors. Cumulatively, these data indicates that Trm are a distinct memory T cell population disconnected from the circulating memory T cell pool and displaying a unique molecular signature which likely results in optimal survival and function within their local environment. 13 samples were analyzed: 5 replicates of memory OT-I CD8+.CD103- T cells isolated from the spleen of mice on day 20 p.i. with VSV-OVA. 5 replicates of memory OT-I CD8+CD103+ T cells isolated from the brain of mice on day 20 p.i. with VSV-OVA; and 3 replicates of memory OT-I.CD8+ CD103- T cells isolated from the brain of mice on day 20 p.i. with VSV-OVA