Molecular Pathways: Interleukin-35 in Autoimmunity and Cancer

Immunosuppressive functions conferred by regulatory cytokines are important for maintaining homeostasis in immune responses. IL-35 has recently emerged as a novel regulator of immune responses. Once thought to be specifically expressed by T regulatory cells, induction of IL-35 expression has now been detected in multiple cell types in a variety of diseases, prompting research into regulation of its expression, signaling specificity, target cell populations and functional outputs. Recent studies have revealed that by directing de novo generation of regulatory T and B cells and inhibiting T effector responses, IL-35 plays an important role in development of autoimmune diseases and cancer. IL-35 is overexpressed in a variety of cancers and may exert its function both on anti-tumor immune responses as well as directly on tumor cells. As such, IL-35 is rapidly emerging as a promising biomarker and an attractive cancer therapy target