title: Prevalent CD8(+) T cell response against one peptide/MHC complex in autoimmune diabetes.
abstract: Spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice is the result of a CD4(+) and CD8(+) T cell-dependent autoimmune process directed against the pancreatic beta cells. CD8(+) T cells play a critical role in the initiation and progression of diabetes, but the specificity and diversity of their antigenic repertoire remain unknown. Here, we define the structure of a peptide mimotope that elicits the proliferation, cytokine secretion, differentiation, and cytotoxicity of a diabetogenic H-2K(d)-restricted CD8(+) T cell specificity (NY8.3) that uses a T cell receptor alpha (TCRalpha) rearrangement frequently expressed by CD8(+) T cells propagated from the earliest insulitic lesions of NOD mice (Valpha17-Jalpha42 elements, often joined by the N-region sequence M-R-D/E). Stimulation of splenic CD8(+) T cells from single-chain 8. 3-TCRbeta-transgenic NOD mice with this mimotope leads to preferential expansion of T cells bearing an endogenously derived TCRalpha chain identical to the one used by their islet-associated CD8(+) T cells, which is also identical to the 8.3-TCRalpha sequence. Cytotoxicity assays using islet-derived CD8(+) T cell clones from nontransgenic NOD mice as effectors and peptide-pulsed H-2K(d)-transfected RMA-S cells as targets indicate that nearly half of the CD8(+) T cells recruited to islets in NOD mice specifically recognize the same peptide/H-2K(d) complex. This work demonstrates that beta cell-reactive CD8(+) T cells mount a prevalent response against a single peptide/MHC complex and provides one peptide ligand for CD8(+) T cells in autoimmune diabetes.
authors.affiliation: Department of Microbiology and Infectious Diseases, The University of Calgary, Faculty of Medicine, 3330 Hospital Drive N.W., Calgary, Alberta, Canada T2N 4N1.
authors.forename: B
authors.initials: B
authors.lastname: Anderson
authors.forename: B J
authors.initials: BJ
authors.lastname: Park
authors.forename: J
authors.initials: J
authors.lastname: Verdaguer
authors.forename: A
authors.initials: A
authors.lastname: Amrani
authors.forename: P
authors.initials: P
authors.lastname: Santamaria
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D019673:Genes, T-Cell Receptor alpha; D007515:Islets of Langerhans / Q000276:immunology; D008213:Lymphocyte Activation; D008285:Major Histocompatibility Complex; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000235:genetics; D013154:Spleen / Q000276:immunology; D014158:Transcription, Genetic
chemical_list: D016207:Cytokines; D010446:Peptide Fragments; D016693:Receptors, Antigen, T-Cell, alpha-beta