IL-17 in obesity and adipogenesis.

The pro-inflammatory cytokine interleukin (IL)-17 (also known as IL-17) has been associated with induction of tissue inflammation. Obese individuals exhibit many symptoms of chronic low-grade inflammation, suggesting that IL-17 may impact adipose tissue. However, the role of IL-17 in obesity is largely unexplored. Emerging studies indicate that obesity selectively promotes expansion of the Th17 T-cell lineage, exacerbating disease in murine models of autoimmunity such as EAE and colitis. Human studies support this concept, as new clinical studies suggest that IL-17 is expressed at elevated levels in obese individuals. Conversely, however, an anti-adipogenic role for IL-17 is becoming evident, and therefore the interconnections between IL-17 and fat metabolism may be quite complex. Here, we consolidate the potential implications of IL-17 in relation to obesity and describe the emerging data regarding the role of IL-17 in adipose tissue.