Epigenomic priming of immune genes implicates oligodendroglia in multiple sclerosissusceptibility

Multiple sclerosis (MS) is characterized by a targeted attack on oligodendroglia (OLG)and associated myelin by immune cells, which are thought to be the main drivers of MS susceptibility. Assessing chromatin accessibility and the transcriptome simultaneously at the single cell level, we found that immune genes exhibit a primedchromatin state in mouse and human OLG in a non-disease context, compatible withrapid transitions to immune-competent states in MS. We identified transcription factors as BACH1 and STAT1 involved in immune gene regulation in oligodendrocyteprecursor cells (OPCs). A subset of immune genes present bivalency of H3K4me3/H3K27me3 in OPCs, with Polycomb inhibition leading to their increased activation upon interferon-gamma (IFNg) treatment. Some MS susceptibility single-nucleotide polymorphisms (SNPs) overlap with these regulatory regions in mouse andhuman OLG, and treatment of mouse OPCs with IFNg leads to chromatin architecture remodeling at these loci and altered expression of interacting genes. Our data indicates that susceptibility for MS may involve OLG, which therefore constitute novel targets for immunological-based therapies for MS.EGA study EGAS00001005911