CHD7 promotes anti-viral short-lived effector CD8+ T cells

CD8+ T cells differentiate into two subpopulations in response to acute viral infection: memory precursor effector cells (MPECs) and short-lived effector cells (SLECs). MPECs and SLECs are epigenetically distinct; however, the epigenetic regulators required for formation of these subpopulations are mostly unknown. Here we performed an in vivo CRISPR screen in murine naive CD8+ T cells to identify the epigenetic regulators required for MPEC and SLEC formation, using the acute lymphocytic choriomeningitis virus (LCMV) Armstrong infection model. We identified the ATP-dependent chromatin remodeler chromodomain-helicase-DNA-binding-protein-7 (CHD7) as a positive regulator of SLEC formation, as knockout (KO) of Chd7 reduced SLECs numerically. In contrast, KO of Chd7 increased the formation of central memory T cells following pathogen clearance yet attenuated memory cell expansion following a rechallenge. These findings establish CHD7 as a novel positive regulator of SLEC and negative regulator of central memory T cell formation. To investigate the open chromatin regions in CD8+ T cells responding to LCMV Armstrong infection we performed ATACseq.