title: Overexpression of CIITA in T cells aggravates Th2-mediated colitis in mice.
abstract: The MHC class II transactivator (CIITA) is the master transcriptional regulator of genes involved in MHC class II restricted antigen presentation. Previously we suggested another role of CIITA in Th1/Th2 balance by demonstrating that forced expression of CIITA in murine T cells repressed Th1 immunity both in vitro and in vivo. However, the results were contradictory to the report that CIITA functioned to suppress the production of Th2 cytokine by CD4+ T cells in CIITA deficient mice. In this study, we investigated the influence of constitutive expression of CIITA in T cells on Th2 immune response in vivo using murine experimental colitis model. In the dextran sodium sulfate-induced acute colitis, a disease involving innate immunity, CIITA transgenic mice and wild type control mice showed similar progression of the disease. However, the development of oxazolone-induced colitis, a colitis mediated by predominantly Th2 immune response, was aggravated in CIITA-transgenic mice. And, CD4+ T cells from the mesenteric lymph node of CIITA-transgenic mice treated with oxazolone exhibited a high level of IL-4 secretion. Together, these data demonstrate that constitutive expression of CIITA in T cells skews immune response to Th2, resulting in aggravation of Th2-mediated colitis in vivo.
authors.affiliation: Department of Pathology, Hallym University College of Medicine, Chuncheon, Korea.
authors.forename: Tae Woon
authors.initials: TW
authors.lastname: Kim
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Choi
authors.forename: Kyeong Cheon
authors.initials: KC
authors.lastname: Jung
mesh_terms: D000818:Animals; D003092:Colitis / Q000209:etiology*; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009687:Nuclear Proteins / Q000502:physiology*; D010081:Oxazolone / Q000494:pharmacology; D013601:T-Lymphocytes / Q000378:metabolism*; D018418:Th2 Cells / Q000276:immunology*; D015534:Trans-Activators / Q000502:physiology*
chemical_list: C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D015534:Trans-Activators; D010081:Oxazolone; D015847:Interleukin-4