title: Distinct roles of IL-22 in human psoriasis and inflammatory bowel disease.
abstract: IL-22, an IL-10 family cytokine, is produced by different leukocyte subsets, including T cells, NK cells and lymphoid tissue inducer (LTi) cells. IL-22 mediates the crosstalk between leukocytes and tissue epithelia because its receptor is preferentially expressed on various tissue epithelial cells. IL-22 is essential for host defense against infections of extracellular pathogens, such as bacteria and yeasts, by eliciting various innate defensive mechanisms from tissue epithelial cells and promoting wound-healing responses. In autoimmune diseases, however, diverse tissue microenvironments and underlying pathogenic mechanisms may result in opposing contributions of IL-22 in disease progression. For example, in psoriasis, IL-22 can synergize with other proinflammatory cytokines to induce many of the pathogenic phenotypes from keratinocytes and exacerbate disease progression. In contrast, IL-22 plays a beneficial role in IBD by enhancing barrier integrity and epithelial innate immunity of intestinal tract.
authors.affiliation: Department of Immunology, Genentech, Inc., 1 DNA Way, M/S 34, South San Francisco, CA 94080, USA. ouyang@gene.com
authors.forename: Wenjun
authors.initials: W
authors.lastname: Ouyang
mesh_terms: D000818:Animals; D006801:Humans; D007113:Immunity, Innate; D015212:Inflammatory Bowel Diseases / Q000276:immunology*; D007378:Interleukins / Q000502:physiology*; D051379:Mice; D011565:Psoriasis / Q000276:immunology*; D000097043:Interleukin-22
chemical_list: D007378:Interleukins; D000097043:Interleukin-22