Inflammation-dependent differentiation of two distinct regulatory T cell populations in the visceral adipose tissue shapes systemic metabolism [RNA-seq II]

Visceral adipose tissue (VAT) is an endocrine organ critical for energy storage and metabolic homeostasis. Its function, at least in part, is controlled by immune cells, including Foxp3+ regulatory T (Treg) cells, which restrain VAT inflammation and glucose intolerance. Here we uncover that the VAT harbours two distinct Treg cell populations, prototypical ST2+ Treg cells, that are enriched in males and depend on the cytokine IL-33 and the transcription factor PPAR?? and a previously uncharacterized population of VAT Treg cells that express the chemokine receptor CXCR3+, are enriched in females and depend on the transcription factor T-bet. We further show that the transcription factor GATA3 promoted differentiation of ST2+ VAT Treg cells and together with PPAR? and IL-33 repressed the differentiation of CXCR3+ Treg cells. CXCR3+ VAT Treg cells developed from naïve Treg cells in a cytokine IFN-? dependent manner. Finally, we demonstrate that ST2+ Treg cells promoted glucose tolerance, while CXCR3+ Treg cells limited VAT inflammation in a sex specific manner. This study for the first time establishes how inflammation determines the developmental trajectories of two functionally and molecularly distinct Treg cell types in the VAT. Overall design: Bulk RNA sequencing of VAT Treg cells obtained from male and female wildtype, Gata3KO and Tbet KO mice. In the KO mice, Gata3 and Tbet transcription factors are ablated in a Treg specific manner using Foxp3Cre