title: The Th17 cell population and the immune homeostasis of the gastrointestinal tract.
abstract: Th17 cells are a recently discovered subset of CD4(+) T lymphocytes filling a hole in the repertoire of effector T cells. Th17 cells produce multiple cytokines, with pivotal impact on immune homeostasis, inflammation, and influencing a wide range of intestinal cell targets. The current issue of the International Reviews of Immunology is entirely dedicated to the various roles of Th17 T cells in the immune homeostasis and inflammation occurring in the gut. In addition to describing diverse Th17-mediated molecular pathways, a specific focus is being given to Th17 cell plasticity. This enables the Th17 cells to shift towards a Th1 profile, or to express IL-22, a protective cytokine in experimental colitis. Participation of microbiota-specific Th17 cells to normal immune homeostasis, and their role in the pathogenesis of inflammatory bowel disease (IBD), or of gluten specific-Th17 cells in celiac disease, are also being discussed. Neutralizing antibodies against IL-17A and IL-17F have commenced clinical testing in IBD. In conclusion, Th17 cells emerge as a key immune cell population and further elucidation of their roles and functional plasticity are warranted to support the discovery of novel therapies against IBD and other intestinal disorders.
authors.affiliation: Section Editor, International Reviews of Immunology, Senior Researcher Institute of Food Sciences , CNR, Avellino , Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Rossi
authors.forename: Adrian
authors.initials: A
authors.lastname: Bot
mesh_terms: D000818:Animals; D041981:Gastrointestinal Tract / Q000276:immunology* / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism; D058504:Th17 Cells / Q000276:immunology* / Q000378:metabolism