title: Increased nonobese diabetic Th1:Th2 (IFN-gamma:IL-4) ratio is CD4+ T cell intrinsic and independent of APC genetic background.
abstract: Autoreactive CD4(+) T cells play a major role in the pathogenesis of autoimmune diabetes in nonobese diabetic (NOD) mice. We recently showed that the non-MHC genetic background controlled enhanced entry into the IFN-gamma pathway by NOD vs B6.G7 T cells. In this study, we demonstrate that increased IFN-gamma, decreased IL-4, and decreased IL-10 production in NOD T cells is CD4 T cell intrinsic. NOD CD4(+) T cells purified and stimulated with anti-CD3/anti-CD28 Abs generated greater IFN-gamma, less IL-4, and less IL-10 than B6.G7 CD4(+) T cells. The same results were obtained in purified NOD.H2(b) vs B6 CD4(+) T cells, demonstrating that the non-MHC NOD genetic background controlled the cytokine phenotype. Moreover, the increased IFN-gamma:IL-4 cytokine ratio was independent of the genetic background of APCs, since NOD CD4(+) T cells generated increased IFN-gamma and decreased IL-4 compared with B6.G7 CD4(+) T cells, regardless of whether they were stimulated with NOD or B6.G7 APCs. Cell cycle analysis showed that the cytokine differences were not due to cycle/proliferative differences between NOD and B6.G7, since stimulated CD4(+) T cells from both strains showed quantitatively identical entry into subsequent cell divisions (shown by CFSE staining), although NOD cells showed greater numbers of IFN-gamma-positive cells with each subsequent cell division. Moreover, 7-aminoactinomycin D and 5-bromo-2'-deoxyuridine analysis showed indistinguishable entry into G(0)/G(1), S, and G(2)/M phases of the cell cycle for both NOD and B6.G7 CD4(+) cells, with both strains generating IFN-gamma predominantly in the S phase. Therefore, the NOD cytokine effector phenotype is CD4(+) T cell intrinsic, genetically controlled, and independent of cell cycle machinery.
authors.affiliation: Division of Rheumatology and Immunology, Department of Medicine, University of Pittsburgh School of Medicine, PA 15261, USA.
authors.forename: Syuichi
authors.initials: S
authors.lastname: Koarada
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Wu
authors.forename: Grace
authors.initials: G
authors.lastname: Olshansky
authors.forename: William M
authors.initials: WM
authors.lastname: Ridgway
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D018106:CD28 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D002453:Cell Cycle; D002455:Cell Division; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D016753:Interleukin-10 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D018448:Models, Immunological; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology* / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology* / Q000473:pathology
chemical_list: D018106:CD28 Antigens; D012333:RNA, Messenger; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma