Acceleration of spontaneous diabetes in TCR-beta-transgenic nonobese diabetic mice by beta-cell cytotoxic CD8+ T cells expressing identical endogenous TCR-alpha chains.
The role of target cell autoantigens and their repertoire vs those of foreign Ags, superantigens, or non-Ag-specific stimuli in the activation and recruitment of effector T cells in most spontaneous models of autoimmune diseases remains elusive. Here we report on the use of single TCR-beta transgenic mice to study the mechanisms that drive the accumulation of pathogenic T cells in the pancreatic islets of nonobese diabetic (NOD) mice, a model for insulin-dependent diabetes mellitus. Expression of the V(beta)8.1+ TCR-beta rearrangement of a diabetogenic H-2Kd-restricted beta cell cytotoxic CD8+ T cell (beta-CTL) clone in NOD mice caused a 10-fold increase in the peripheral precursor frequency of beta-CTL and a selective acceleration of the recruitment of CD8+ T cells to the pancreatic islets of prediabetic animals. This resulted in an earlier onset and a faster progression of beta cell depletion, and led to a dramatic acceleration of the onset of diabetes. Most islet-derived beta-CTL from diabetic transgenic NOD mice expressed an endogenously-derived TCR-alpha sequence identical to that of the clonotype donating the TCR-beta transgene, and a TCR-alpha-CDR3 sequence homologous to those expressed by most islet-derived beta-CTL from nontransgenic NOD mice. TCR-beta transgene expression did not change the peripheral frequency of beta cell-specific CD4+ T cells, the rate at which these cells accumulated in the pancreatic islets, or the incidence of diabetes. Taken together, our data indicate that retention of CD8+ and CD4+ T cells in the pancreatic islets of NOD mice is driven by beta cell autoantigens, rather than by local superantigens or non-Ag-specific stimuli, and that beta-CTL are major effectors of beta cell damage in spontaneous insulin-dependent diabetes mellitus.
Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Alberta, Canada.
J
J
Verdaguer
J W
JW
Yoon
B
B
Anderson
N
N
Averill
T
T
Utsugi
B J
BJ
Park
P
P
Santamaria
D000595:Amino Acid Sequence; D000818:Animals; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology* / Q000235:genetics / Q000276:immunology*; D016130:Immunophenotyping; D007515:Islets of Langerhans / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism*
D016693:Receptors, Antigen, T-Cell, alpha-beta