IL-17RA in Intestinal Inflammation: Structure, Signaling, Function, and Clinical Application

Interleukin-17 receptor A (IL-17RA) is responsible for both IL-17A and IL-25 (IL-17E) signaling pathways. Current evidences suggest distinct but interactive responses between IL-17A and IL-25 signaling, both of which are critical for intestinal immune homeostasis. IL-17RA is assumed to regulate this counterbalance and therefore becomes a crucial molecule in mucosal immunology. In this review, we will describe the structure of IL-17RA, compare IL-17A and IL-25 signaling pathways, and emphasize on the function of IL-17RA in intestinal inflammation and discuss current evidences of accomplished and ongoing clinical trials with monoclonal antibodies targeting Th17 pathway, especially IL-17RA.