title: Environmental influences on T regulatory cells in inflammatory bowel disease.
abstract: Inflammatory bowel disease (IBD) is characterized by chronic, idiopathic inflammation of the intestine. The disease is thought to result from a combination of genetic and environmental factors which ultimately leads to a mucosal immune system that overreacts to normal constituents of the mucosal microbiota. The inflammation in IBD is primarily mediated by inappropriate production of proinflammatory cytokines by CD4(+) T effector cells, effects that are suppressed by CD4(+) T regulatory cells. Defects in both the function of T regulatory cells, and the ability of T effector cells to be suppressed, have been implicated in IBD. In this review we will discuss environmental factors, including cytokines, vitamins A and D, and commensal bacteria, which influence the phenotype and function of regulatory T cells and thereby alter the course of IBD. We will also discuss how these environmental signals can be manipulated therapeutically in order to improve the function of regulatory T cells and ultimately restore mucosal homeostasis in patients with IBD.
authors.affiliation: Department of Surgery, University of British Columbia and Immunity in Health & Disease, Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, BC, Canada.
authors.forename: Gijs
authors.initials: G
authors.lastname: Hardenberg
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Steiner
authors.forename: Megan K
authors.initials: MK
authors.lastname: Levings
mesh_terms: D000818:Animals; D006706:Homeostasis; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014801:Vitamin A / Q000008:administration & dosage; D014807:Vitamin D / Q000008:administration & dosage; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D014815:Vitamins; D014801:Vitamin A; D014807:Vitamin D