Fig. 1.

C-C motif chemokine receptor 5 (CCR5) promotes obesity-induced inflammation and insulin resistance. Kitade et al. [33] recently identified and characterized a role for CCR5, a CC chemokine receptor, and made several important observations. First, expression of CCR5 and its ligands is significantly increased and is equal to that of CCR2 and its ligands in white adipose tissue (WAT) of obese mice. Second, CCR5⁺ adipose tissue macrophages (ATMs) accumulate in WAT of obese mice. Third, Ccr5^-/- mice are protected from insulin resistance and diabetes through both reduction in ATM accumulation and induction of an alternatively activated, M2 dominant shift in ATM. Taken together, these data indicate that CCR5 provides a novel link between obesity, adipose tissue inflammation, and insulin resistance. TNF, tumor necrosis factor; IL, interleukin; MCP, monocyte chemoattractant protein.