title: Regulatory T cells in inflammatory bowel diseases and colorectal cancer.
abstract: Regulatory T cells (T(regs)) are key elements in immunological self-tolerance. The number of T(regs) may alter in both peripheral blood and in colonic mucosa during pathological circumstances. The local cellular, microbiological and cytokine milieu affect immunophenotype and function of T(regs). Forkhead box P3+ T(regs) function shows altered properties in inflammatory bowel diseases (IBDs). This alteration of T(regs) function can furthermore be observed between Crohn's disease and ulcerative colitis, which may have both clinical and therapeutical consequences. Chronic mucosal inflammation may also influence T(regs) function, which together with the intestinal bacterial flora seem to have a supporting role in colitis-associated colorectal carcinogenesis. T(regs) have a crucial role in the immunoevasion of cancer cells in sporadic colorectal cancer. Furthermore, their number and phenotype correlate closely with the clinical outcome of the disease, even if their contribution to carcinogenesis has previously been controversial. Despite knowledge of the clinical relationship between IBD and colitis-associated colon cancer, and the growing number of immunological aspects encompassing sporadic colorectal carcinogenesis, the molecular and cellular links amongst T(regs), regulation of the inflammation, and cancer development are still not well understood. In this paper, we aimed to review the current data surrounding the role of T(regs) in the pathogenesis of IBD, colitis-associated colon cancer and sporadic colorectal cancer.
authors.affiliation: 2nd Department of Internal Medicine, Semmelweis University, 1088 Budapest, Hungary.
authors.forename: Györgyi
authors.initials: G
authors.lastname: Műzes
authors.forename: Béla
authors.initials: B
authors.lastname: Molnár
authors.forename: Ferenc
authors.initials: F
authors.lastname: Sipos
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000276:immunology / Q000473:pathology; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology; D003106:Colon / Q000276:immunology* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000473:pathology; D003424:Crohn Disease / Q000276:immunology* / Q000473:pathology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007413:Intestinal Mucosa / Q000276:immunology / Q000473:pathology; D010641:Phenotype; D015398:Signal Transduction; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D019139:Tumor Escape
chemical_list: D018836:Inflammation Mediators