title: Healing of intestinal inflammation by IL-22.
abstract: An interleukin (IL)-10 family cytokine, IL-22 is characterized by several unique biological properties, including 1) the target restricted to innate cells; 2) the distinct expression pattern between large and small intestines; 3) alteration of the cellular source depending on several factors; 4) the dual abilities to serve as protective versus proinflammatory mediators in inflammatory responses; and 5) the close association with some major inflammatory bowel disease (IBD) susceptibility genes. The major functions of IL-22 in the intestine are the stimulation of epithelial cells to produce a wide variety of antibacterial proteins, the reinforcement of mucus barrier through stimulation of mucin 1 production under intestinal inflammatory conditions, and the enhancement of epithelial regeneration with goblet cell restitution. Through these beneficial functions, IL-22 contributes to the improvement of some types of experimental chronic colitis, which are mediated by T helper (Th)1 or Th2 responses. Most important, studies using both loss-of-function and gain-of-function approaches have clearly demonstrated the ability of IL-22 to promote intestinal wound healing from acute intestinal injury. These findings highlight IL-22 as an attractive and promising target for future IBD therapy. Alternatively, the enormous progress in the field of IL-22 biology has also suggested more complicated mechanisms with the IL-22 pathway than previously predicted. This review article briefly summarizes previous and current knowledge on IL-22 particularly associated with intestinal inflammation.
authors.affiliation: Molecular Pathology Unit, Massachusetts General Hospital and Department of Pathology, Harvard Medical School, Charlestown, Massachusetts, USA. amizoguchi@partners.org
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizoguchi
mesh_terms: D000818:Animals; D006801:Humans; D007249:Inflammation / Q000517:prevention & control*; D007378:Interleukins / Q000627:therapeutic use*; D007422:Intestines / Q000187:drug effects* / Q000473:pathology; D000097043:Interleukin-22
chemical_list: D007378:Interleukins; D000097043:Interleukin-22