Histone modifications in the promoter regions of T-bet, GATA-3, PU.1, IRF4, and RORC. Freshly isolated naive CD4 T cells from cord blood or adult naive and memory CD4 T cells from the peripheral blood were processed for ChIP analysis. Relative amounts of precipitated DNA from the T-bet, GATA-3, PU.1, IRF4, and RORC promoter regions were assessed. (A) Log₂ of the ratio of relative amounts of DNA precipitated with anti-H3K4me3 to anti-H3K27me3 (top panel) and with anti-H3ac to anti-H3K27me3 (bottom panel). (B) Fraction of the PU.1 promoter DNA precipitated with Abs against H3K4me3, H3ac, or H3K27me3 in relation to the input DNA. The mean ± SEM of at least 3 independent experiments with cells from different donors is demonstrated. Statistical analyses were performed using ANOVA. ***P < .001; *P < .05; n.s. indicates not significant.