Figure 4. Bach2 represses effector programmes to stabilize iTreg cell development.

a, FoxP3 expression in GFP⁺ (transduced) WT and KO naïve splenic CD4⁺ T cells stimulated in the presence of 2ng ml⁻¹ TGF-β and transduced with indicated retroviruses. b, Derepressed genes in KO compared with WT naïve CD4⁺ T cells stimulated under iTreg polarizing conditions. Proportion of effector-lineage associated transcripts (upregulated upon stimulation of naïve CD4+ T cells in Th1, Th2 or Th17 conditions respectively (pie chart) and genes that are directly bound by Bach2 in iTreg cells (outer arc) are shown. c, Heatmap indicating expression of effector-lineage associated transcripts derepressed in KO cells (iTreg conditions), their expression in wildtype Th1, Th2 and Th17 cells and binding at their respective gene loci by Bach2 (gene-body ±2kb). d, Alignments showing binding of Bach2 to selected genes and their mRNA expression in WT and KO cells cultured under iTreg conditions. e, Proliferation and effector cytokine expression in CFSE-labelled WT and KO naïve CD4⁺ T cells stimulated under iTreg conditions for 3 days. f, Transcription factor expression upon stimulation of WT and KO naïve CD4⁺ T cells under iTreg conditions for 3 days in the presence or absence of indicated anti-cytokine neutralizing antibodies. g, Proliferation and effector cytokine expression in CFSE-labelled WT and KO naïve CD4⁺ T cells stimulated under indicated polarizing conditions for 3 days. Data are representative of ≥2 independently repeated experiments (a,e–g).