The fate of CD8+ T cells during infection is linked to their developmental origin [VirtualMemory_and_TrueNaïve_timestamp_ATACseq]

During immune ontogeny the thymus is colonized by distinct waves of hematopoietic stem cells that give rise to unique lineages of immune cells.  In this report, we asked whether the developmental origin of CD8+ T cells influences their response to infection later in adulthood.  To answer this question, we developed a system to ‘timestamp’ CD8+ T cells in situ at various stages of development (1d and 28d) and examined their behavior after post-thymic differentiation.  We found that neonatal-derived CD8+ T cells have an intrinsic propensity to become virtual memory cells prior to infection and are the first cells to proliferate and become effectors after microbial challenge. These data indicate that there are developmental layers in the adult CD8+ T cell response to infection and that the heterogeneity in the effector pool is linked to the variation in the developmental origins of the responding cells. This dataset profiles chromatin accessibility in 1day- and 28day-timestamped virtual memory (CD44hi) and "true naive" (CD44 lo) CD8+ T cells in cells that had undergone the same amount of post-thymic maturation (4 weeks, transgenic mice, different sorts). Profiling chromatin landscape of virtual memory (CD44hi) and "true naïve" (CD44lo) CD8+ T cells (gBT-I TCR transgenic) after 4 weeks of post-thymic maturation, comparing three types of samples: virtual memory cells made at 1 day or 28 days of life, and true naïve cells made at 28 days of life (each in duplicate).