Adipose tissue macrophage in immune regulation of metabolism.

The prevalence of obesity and type 2 diabetes is escalating to an epidemic proportion worldwide. Obesity is known to be associated with a state of chronic, low-grade inflammation. Emerging lines of evidence have shown that both innate and adaptive immune responses play crucial roles in the control of metabolic homeostasis. Macrophages in adipose tissues are the essential effector cells in orchestrating metabolic inflammation, which is thought to promote the pathogenic progression of obesity and obesity-related disorders. Here we discuss our current understanding of the distinct modes of activation of adipose tissue macrophages, which can sense the metabolic cues and exert profound effects upon adipose homeostasis. Targeting macrophages in adipose tissues may provide new avenues for developing immunomodulation-based therapeutics against obesity and obesity-associated metabolic diseases.