Versatile molecule protects against IBD

Immune system signaling molecules known as cytokines are believed to play a major inflammatory role in autoimmune diseases, in which the body’s immune defenses somehow turn on its own cells.

Things aren’t so simple in the case of the cytokine interleukin-22 (IL-22; right), which promotes the inflammation of skin cells seen in psoriasis but appears to protect cells in inflamed livers. Scientists from the laboratory of Richard A. Flavell,Ph.D., Sterling Professor of Immunobiology, and Regeneron Pharmaceuticals have now found that IL-22 also plays a protective role in inflammatory bowel disease (IBD; see “Intestinal Fortitude”). As reported in the December issue of Immunity, mice that were deficient in interleukin-22 had more severe forms of colitis and higher mortality.

Postdoctoral associate and first author Lauren A. Zenewicz, Ph.D., says the discovery could lead to IBD treatments without the side effects of current immunosuppressive therapies, which include increased susceptibility to infections.