The obesity-induced adipokine sST2 exacerbates adipose T_reg and ILC2 depletion and promotes insulin resistance.

Abstract

Depletion of fat-resident regulatory T cells (T_regs) and group 2 innate lymphoid cells (ILC2s) has been causally linked to obesity-associated insulin resistance. However, the molecular nature of the pathogenic signals suppress adipose T_regs and ILC2s in obesity remains unknown. Here, we identified the soluble isoform of interleukin (IL)-33 receptor ST2 (sST2) as an obesity-induced adipokine that attenuates IL-33 signaling and disrupts T_reg/ILC2 homeostasis in adipose tissue, thereby exacerbates obesity-associated insulin resistance in mice. We demonstrated sST2 is a target of TNFα signaling in adipocytes that is countered by Zbtb7b. Fat-specific ablation of Zbtb7b augments adipose sST2 gene expression, leading to diminished fat-resident T_regs/ILC2s, more pronounced adipose tissue inflammation and fibrosis, and impaired glucose homeostasis in mice. Mechanistically, Zbtb7b suppresses NF-κB activation in response to TNFα through destabilizing IκBα. These findings uncover an adipokine-immune signaling pathway that is engaged in obesity to drive the pathological changes of the immunometabolic landscape.