Helios enhances the preferential differentiation of human fetal CD4+ naïve T cells into regulatory T cells. [Epigenetics]

Human fetal naïve T cells preferentially differentiate into CD25hiFOXP3hi regulatory T (Treg) cells upon T cell receptor (TCR) stimulation, which contribute to the generation of immunotolerance in the developing human fetus. We utilized ATACseq and H3K27ac ChIPseq to characterize the human fetal naive T cell epigenome relative to that of adult naive T cells and Treg cells. Fetal naive T cells share a partial Treg epigenome with increased chromatin accessibility and H3K27ac enrichment at a subset of Treg-specific enhancers. ATACseq and H3K27ac ChIPseq for ex vivo sorted adult CD4+CD25-CD45RA+CD27+ naïve T, adult CD4+CD25hiCD127lo regulatory T and fetal naïve T cells from fetal spleen and adult peripheral blood mononuclear cells