Nature. Gender differences in Treg cells.

In response to foreign or self antigens, there are some differences between the sexes.gene and hormone differences between the two sexes, as well as environmental factors, may lead to immune differences between the two sexes (see bioart report: nature highlights | Qihai team found a new mechanism of gender differences in antibody immune response).the sexual dimorphism of this immune response also leads to the differences in the occurrence of autoimmune diseases, malignant diseases, infectious diseases and vaccine responses between the two sexes to a certain extent.however, the detailed characteristics of gender dimorphism of immune response and its mechanism are still unclear.on February 26, 2020, Axel kallies and ajithkumar vasanthakumar from the University of Melbourne, Australia, published a paper entitled "sex specific adipose tissue implanting of regulatory T cells" in nature The proportion and function of cells (Treg) have obvious gender dimorphism. Compared with female mice, there are more Tregs in vat of male mice. The specific mechanism of this difference is described.the research team first analyzed and compared the immune cell composition in perigonal vat of male and female mice. It was found that the proportion and number of Treg in vat of male mice were higher than that of female mice of the same age, while other immune cells in VAT had no difference. At the same time, vat of male mice had no difference Treg expressed higher levels of IL-33 receptor ST2, klrg1 and CCR2, and produced more immunosuppressive IL-10 cytokines. The gender dimorphism ofTreg was found in VAT, and there was no difference in Treg between male and female mice in other lymphoid or non lymphoid tissues.further sequencing analysis showed that there were different transcriptomics and chromatin accessibility characteristics in vat of male and female mice.the research team explored the mechanism of gender dimorphism of Treg in VAT in mice, and found that the proportion of Treg in VAT decreased significantly in male mice with androgen receptor knockout, and the phenotype was more similar to that of wild-type female mice, while the proportion of Treg in VAT increased with estrogen receptor α knockout in female mice.subsequently, it was found that the expression of androgen receptor other than Treg in VAT plays a key role in the gender dimorphism of Treg in VAT.by analyzing adipocytes, endothelial cells, stromal cells and a series of experiments in vat of male and female mice, it was found that Treg cells could be recruited into VAT in a ccl2-ccr2 dependent manner, and then IL-6 could induce the expression of BLIMP1 transcription factor in Treg cells and activate the expression of IL-33 receptors ST2, CCR2 and IL-10 in Treg.the stromal cells in vat of male mice secrete IL-33 under the stimulation of androgen, which promotes the expansion of Treg in VAT, thus mediating the inhibition of immune inflammation in VAT.and estrogen can inhibit this process, resulting in gender dimorphism in the number and function of Treg in vat of mice (Fig. 1).Fig. 1 recruitment, expansion and function of Treg cells in VAT mediated by sex hormones. In conclusion, this study demonstrated the gender dimorphism of the number and phenotype of Treg cells in visceral adipose tissue of mice, and elaborated the detailed mechanism, which further increased the understanding of the difference of immune response between the two sexes.original link: plate maker: Qijun reference 1. Klein SL, Flanagan KL. Sex differences in immune responses. Nat Rev immune.2016; 16 (10): 626 – 638 doi:10.1038/nri.2016.90