Inhibiting RORγt/Th17 axis for autoimmune disorders

The recent success reported in late-stage clinical trials for the treatment of psoriasis by antibodies directed against interleukin (IL)-17 or its receptor has validated and strongly supports the development of inhibitors of the IL-17 pathway as a new therapeutic modality in chronic inflammation and autoimmunity. These results also encourage the drug discovery of orally available small molecules that can modulate down the production of IL-17 by Th17 cells (the major IL-17 producers) or the downstream signaling of the IL-17 receptor. Here, we review these strategies with an emphasis on inhibiting the retinoic-acid-related orphan nuclear receptor ROR gamma t, which is the master regulator of Th17 cells and a promising therapeutic target for the treatment of multiple autoimmune disorders.