title: IL-22: a critical mediator in mucosal host defense.
abstract: IL-22 is an IL-10 family cytokine member that was recently discovered to be produced by Th17 cells. Current studies have revealed that IL-22 targets cells of the digestive, skin, and respiratory organ systems and plays an important role in mucosal immunity. The IL-22 receptor (IL-22R) is expressed exclusively in these tissues, thereby allowing the cytokine to mediate epithelial innate immunity in response to a variety of pathogens. Although recent studies have shown the importance of IL-22 in host defense against Gram-negative bacterial organisms (in gut and lung), there is evidence that IL-22 also plays a role in autoimmune disease, such as psoriasis. IL-22 therefore, not unlike other cytokines, has complex pro-inflammatory, anti-inflammatory, and autoimmune effects which continue to be under further investigation. This review will focus on what is known about IL-22 and its function in mucosal host defense.
authors.affiliation: Division of Pulmonary Medicine, Allergy and Immunology, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA. shean.aujla@chp.edu
authors.forename: S J
authors.initials: SJ
authors.lastname: Aujla
authors.forename: J K
authors.initials: JK
authors.lastname: Kolls
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D018928:Immunity, Mucosal / Q000276:immunology*; D020381:Interleukin-17 / Q000096:biosynthesis / Q000276:immunology; D007378:Interleukins / Q000096:biosynthesis / Q000276:immunology*; D008954:Models, Biological; D000097043:Interleukin-22
chemical_list: D020381:Interleukin-17; D007378:Interleukins; D000097043:Interleukin-22