a, Expression of Foxp3 (RFP) and Blimp1 (GFP) in splenic CD4+ T cells from Foxp3RFPBlimp1GFP mice. b, Expression of Blimp1 (GFP) and KLRG1 in splenic T reg cells. c, Pparg expression in Blimp1 (GFP)+ versus Blimp1 (GFP)− splenic T reg cells. Bar graph generated from RNA-seq read counts26. d, Expression of KLRG1 and CCR2 in splenic T reg cells from Foxp3cre and Blimp1fl/flFoxp3cre mice. e, Graphs on the right show percentages of KLRG1+ cells among splenic T reg cells of Foxp3cre (n = 5) and Blimp1fl/flFoxp3cre (n = 6) mice and percentages of CCR2+ cells within the KLRG1+ fraction of splenic T reg cells. f, Proportion of Blimp1 (GFP)+ T reg cells obtained after Blimp1 (GFP)− T reg cells were sorted from Foxp3RFPBlimp1GFP mice and cultured in the presence of indicated cytokines (n = 3–4). g, Expression of Il6 transcripts as measured by quantitative PCR in haematopoietic cell populations sorted from the male VAT (n = 6). h, Flow cytometry plots (left) and quantification (right) of ILC2s in the VAT of male wild-type and Il6−/− (n = 4 per genotype) mice. i, Flow cytometry histograms show expression of indicated markers in wild-type and Il6−/− VAT T reg cells. j, Expression of CD73 and CD90 in wild-type and Il6−/− (n = 4 per genotype) VAT Gp38+ cells (left). Percentages of CD73+CD90− and CD73+CD90+ stromal cells in the VAT of male wild-type and Il6−/− (n = 4 per genotype) mice (right). k, Percentages of VAT T reg cells in male Il6−/− mice treated with PBS or IL-33. Two-tailed unpaired t-test. Data are mean ± s.d. Data pooled or representative of two independent experiments. l, Model of the sex-hormone-mediated circuitry that mediates recruitment, expansion and function of VAT T reg cells. T reg cells are recruited to the VAT in a CCL2–CCR2-dependent manner. IL-6 induces the expression of transcription factor BLIMP1, which in turn activates expression of prototypical VAT T reg signature genes IL-33 receptor ST2, CCR2 and IL-10. IL-33 production by androgen-responsive stromal cells leads to local expansion of VAT T reg cells in the male VAT, which in turn mediate repression of VAT inflammation. Source data