Epigenetic control of innate and adaptive immune memory [ATAC-Seq]

Clonal expansion and immunological memory are hallmark features of the mammalian adaptive immune response and essential for prolonged host control of pathogens. Recent work demonstrated that natural killer (NK) cells of the innate immune system also exhibit these adaptive traits during infection. Here we demonstrate that differentiating and ‘memory’ NK cells possess distinct chromatin accessibility states, and that their epigenetic profiles reveal a ‘poised’ regulatory program at the memory stage. Furthermore, we elucidate how individual STAT proteins differentially control epigenetic and transcriptional states early during infection. Finally, concurrent chromatin profiling of the canonical CD8+ T cell response against the same infection demonstrated parallel and distinct epigenetic signatures defining NK cells and CD8+ T cells. Overall, our study reveals the dynamic nature of epigenetic imprinting during the generation of innate and adaptive lymphocyte memory. ATAC-seq was performed on NK cells harvested during in-vivo infection.