Ess2 regulates IL-7-dependent cell survival in naïve CD4+T cells.Ess2fl/fl and Ess2ΔCD4/ΔCD4 naïve T cells were cultured with or without 100 ng ml−1 of IL-7. A, RNA-seq peaks in the IL7r promoter from CD4SP cells and naïve T cells by IGV. B, RT-qPCR of Il7r in CD4SP cells and naïve T cells normalized to the level of Gapdh mRNA expression. Three to five mice were used in each experiment, ∗p < 0.05. C, ChIP-qPCR analysis of the Il7r promoter with anti-Ess2 and anti-histoneH3K36me3 antibodies in primary naïve CD4+ T cells. D, representative apoptotic cells stained by Annexin V using flow cytometry (MoFlo XDP). Central and left peaks were Annexin-positive cells, and the percentages are described. E, representative confocal microscopy of apoptotic (red), necrotic (green), and DAPI (blue) staining; Scale bar = 50 μm. F, quantification of apoptotic cells. The number of cells counted is from 50 to 80. Each sample was counted in at least five areas. G, Presto blue staining of naïve CD4+ T cells stimulated with and without anti-CD3ε/CD28 antibodies and/or IL-7 for 2 days. Each experiment was performed at least three times, and the results are presented as the mean ± SD. p values were calculated using a Student’s t test, ∗p < 0.05. ChIP, chromatin immunoprecipitation assay; qPCR, quantitative polymerase chain reaction.