Epigenetic Memory of HSC after LPS injection (ATAC-Seq)

Here we show that immune challenge can induce epigenetic memory in HSC. We show that LPS, a gram-negative bacterial component, induces changes in HSC differentiation and gene expression that returned rapidly to normal but also establish novel open chromatin regions (OCR) that persist long term. These OCR are associated with genes involved in myeloid lineage commitment and innate immunity, that become more highly expressed upon a secondary bacterial challenge and enable LPS-exposed HSCs to mount an increased myeloid differentiation and accelerated immune response. Mice were injected with 125 ug of LPS IP or PBS. ATAC-seq was performed on HSC KSL Flt3- sorted 0, 4 weeks or 12 weeks after LPS injection. Samples are from pool of 4-8 mice.