title: Regulation of type 1 diabetes by a self-MHC class II peptide: role of transforming growth factor beta (TGF-beta).
abstract: The present study was undertaken to analyze the regulatory T cells generated in response to class I derived self-I-A beta(g7) (54-76) peptide. It was observed T cells from young unprimed type 1 diabetes (T1D) prone NOD mice did not respond to self-I-A beta(g7) (54-76) peptide although T cells from primed young NOD mice showed a strong response. T cells from young unprimed BALB/c mice responded to self-I-A beta(d) (62-78) peptide. However, a breakdown of tolerance to these peptides was observed with age in both the strains. Culture supernatant from I-A beta(g7) (54-76) peptide-primed cells secreted large amounts of TGF-beta and inhibited T cell responses in allogeneic-MLR. Further, I-A beta(g7) (54-76) peptide specific T cell lines from young (I-A.Y) and diabetic (I-A.D) NOD mice were established. I-A.Y secreted IL-4, TGF-beta and IL-10 while I-A.D T cell line secreted IL-10 and IFN-gamma. We found that I-A.D T cell line induced diabetes when transferred in NOD/SCID mice but I-A.Y T cell line did not induce disease. These results show that immunization of NOD mice with I-A beta(g7) (54-76) peptide at a younger age induces a regulatory T cell response suggesting that correcting the defects in immunoregulatory mechanisms using self-MHC peptides may be one of the approaches to prevent autoimmune diseases like T1D.
authors.affiliation: Department of Microbiology and Immunology, University of Western Ontario, John P. Robarts Research Institute, London, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Mukherjee
authors.forename: P
authors.initials: P
authors.lastname: Chaturvedi
authors.forename: B
authors.initials: B
authors.lastname: Agrawal
authors.forename: B
authors.initials: B
authors.lastname: Singh
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010455:Peptides / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D016212:Transforming Growth Factor beta
chemical_list: D001324:Autoantigens; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D016212:Transforming Growth Factor beta