Interleukin 35 (IL35)

Interleukin 35 (IL-35) is an IL-12 family cytokine that is produced by regulatory, but not effector, T cells and plays a role in immune suppression. It is a dimeric protein composed of IL-12alpha; and IL-27beta; chains, which are encoded by two separate genes called IL12A and EBI3, respectively.

Secreted by regulatory T cells (Tregs), IL-35 suppresses inflammatory responses of immune cells. Studies in mice show the absence of either IL-35 chain from regulatory Tregs reduces the cells ability to suppress inflammation; this has been observed during cell culture experiments and using an experimental model for inflammatory bowel disease. To produce its suppressive effects, IL-35 has selective activities on different T cell subsets; it induces proliferation of Treg cell populations but reduces activity of Th17 cell populations.