title: Spontaneous autoimmune diabetes in monoclonal T cell nonobese diabetic mice.
abstract: It has been established that insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a CD4+ and CD8+ T cell-dependent autoimmune process directed against the pancreatic beta cells. The precise roles that beta cell-reactive CD8+ and CD4+ T cells play in the disease process, however, remain ill defined. Here we have investigated whether naive beta cell-specific CD8+ and CD4+ T cells can spontaneously accumulate in pancreatic islets, differentiate into effector cells, and destroy beta cells in the absence of other T cell specificities. This was done by introducing Kd- or I-Ag7-restricted beta cell-specific T cell receptor (TCR) transgenes that are highly diabetogenic in NOD mice (8.3- and 4.1-TCR, respectively), into recombination-activating gene (RAG)-2-deficient NOD mice, which cannot rearrange endogenous TCR genes and thus bear monoclonal TCR repertoires. We show that while RAG-2(-/-) 4.1-NOD mice, which only bear beta cell-specific CD4+ T cells, develop diabetes as early and as frequently as RAG-2+ 4.1-NOD mice, RAG-2(-/-) 8.3-NOD mice, which only bear beta cell-specific CD8+ T cells, develop diabetes less frequently and significantly later than RAG-2(+) 8.3-NOD mice. The monoclonal CD8+ T cells of RAG-2(-/-) 8.3-NOD mice mature properly, proliferate vigorously in response to antigenic stimulation in vitro, and can differentiate into beta cell-cytotoxic T cells in vivo, but do not efficiently accumulate in islets in the absence of a CD4+ T cell-derived signal, which can be provided by splenic CD4+ T cells from nontransgenic NOD mice. These results demonstrate that naive beta cell- specific CD8+ and CD4+ T cells can trigger diabetes in the absence of other T or B cell specificities, but suggest that efficient recruitment of naive diabetogenic beta cell-reactive CD8+ T cells to islets requires the assistance of beta cell-reactive CD4+ T cells.
authors.affiliation: Department of Microbiology and Infectious Diseases, The University of Calgary, Faculty of Medicine, Alberta, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Verdaguer
authors.forename: D
authors.initials: D
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: Amrani
authors.forename: B
authors.initials: B
authors.lastname: Anderson
authors.forename: N
authors.initials: N
authors.lastname: Averill
authors.forename: P
authors.initials: P
authors.lastname: Santamaria
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000209:etiology / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002999:Clone Cells; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000235:genetics / Q000276:immunology*; D018450:Disease Progression; D005260:Female; D017353:Gene Deletion; D016654:Genes, RAG-1 / Q000276:immunology; D007399:Interphase / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D008822:Mice, Transgenic; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta