Loss of Lkb1 in CD11c(+) myeloid cells protects mice from diet-induced obesity while enhancing glucose intolerance and IL-17/IFN-gamma imbalance

Adipose tissue CD11c(+) myeloid cell is an independent risk factor associated with obesity and metabolic disorders. However, the underlying molecular basis remains elusive. Here, we demonstrated that liver kinase B1 (Lkb1), a key bioenergetic sensor, is involved in CD11c(+) cell-mediated immune responses in diet-induced obesity. Loss of Lkb1 in CD11c(+) cells results in obesity resistance but lower glucose tolerance, which accompanies tissue-specific immune abnormalities. The accumulation and CD80's expression of Lkb1 deficient adipose-tissue specific dendritic cells but not macrophages is restrained. Additionally, the balance of IL-17A and IFN-gamma remarkably tips towards the latter in fat T cells and CD11c(-) macrophages. Mechanistically, IFN-gamma promotes apoptosis of preadipocytes and inhibits their adipogenesis while IL-17A promotes the adipogenesis in vitro, which might account in part for the fat gain resistant phenotype. In summary, these findings reveal that Lkb1 is essential for fat CD11c(+) dendritic cells responding to HFD exposure and provides new insights into the IL-17A/IFN-gamma balance in HFD-induced obesity.