Interleukin-22 in kidney injury and regeneration.

Interleukins have become well-known regulators of innate and adaptive immunity-related tissue inflammation. Recently, IL-22 has gained a lot of interest for its unique functions in maintaining and regaining epithelial integrity. IL-22 is exclusively secreted by different immune cell subsets, while IL-22 receptors are mainly expressed by epithelial cells. As the kidney is largely an epithelial organ, the functional role of IL-22 in the kidney deserves to be explored in detail. Here, we briefly summarize the key features of IL-22 biology and review the available data on its expression and functional roles in kidney injury and kidney regeneration. Furthermore, we provide suggestions on how to explore this evolving field in the future.