Adipose ILC2s depend on acetyl-CoA carboxylase 1 to maintain metabolic health

Adipose group 2 innate lymphoid cells (ILC2s) are essential to maintain metabolic homeostasis. Obesity severely impairs the number and function of ILC2s, resulting in the progression of metabolic inflammation. How ILC2s are perturbed in obesity remains unknown. Here, we find that high-fat diet (HFD)-induced obesity in mice increases fatty acid oxidation, leading to suppression of acetyl-coenzyme A (CoA) carboxylase 1 (ACC1) in adipose ILC2s. ACC1 is essential for maintaining the citrate shuttle, NAD⁺/NADH balance, and cellular metabolism. Mimicking the effects of HFD, ACC1 deletion impairs differentiation, maintenance, and function of ILC2s. This results in adipose tissue hypertrophy and inflammation at steady state, predisposing mice to the development of diabetes. Supplementing with the NAD⁺ precursor nicotinamide riboside rescues ACC1 deficiency, restoring ILC2 function and adipose tissue homeostasis. These findings establish ACC1 as a critical regulator of adipose ILC2 maintenance and function and provide a rationale for the adverse effects of ACC inhibition in obesity.