Beta-cell-cytotoxic CD8+ T cells from nonobese diabetic mice use highly homologous T cell receptor alpha-chain CDR3 sequences.
Insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a cell-mediated autoimmune process against pancreatic beta-cells. We have shown that beta-cell-cytotoxic CD8+ T cell clones can transfer IDDM to irradiated NOD mice if co-injected with nondiabetogenic CD4+ spleen T cells. To determine whether CTLs recruited to pancreatic islets recognize a restricted set of local Ags, we sequenced TCR-alpha and TCR-beta cDNA generated by anchor PCR from CD8+ CTL lines and clones derived from islets of 10 different NOD mice. These CTL lines were oligoclonal, but did not show skewed V alpha, V beta, J alpha, or J beta gene usage when compared with CD8+ spleen T cells. However, of the 26 different CTL-derived TCR-alpha sequences from all of these CTL lines and clones, 17 (65%) used one of three highly related, N region-encoded, CDR3 motifs. Motifs 1 and 2 (7 clonotypes each) contained a hydrophobic amino acid followed by Arg and a negatively charged or a polar residue (Asn or Gly), respectively. Motif 3 (3 clonotypes) was x-Arg-Gly. In 12 of these 17 rearrangements, the core sequence was followed by Tyr or Ser. By contrast, none of 31 different TCR-alpha rearrangements used by CD8+ spleen T cells encoded motifs 1 or 2, and only one encoded motif 3. Different TCR-beta rearrangements within individual lines also used homologous CDR3 sequences, but these sequences varied between lines. Skewed TCR-alpha-CDR3 usage by islet-derived CTLs was substantiated further by isolation of CTL clones transcribing highly homologous TCR-alpha, but different TCR-beta, rearrangements. These data suggest that CTLs recruited to pancreatic islets during spontaneous IDDM recognize a restricted set of beta-cell autoantigenic determinants.
Santamaria
P
P
Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Alberta, Canada.
Utsugi
T
T
Park
B J
BJ
Averill
N
N
Kawazu
S
S
Yoon
J W
JW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D004247:DNA / Q000235:genetics; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology*; D005260:Female; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D014644:Genetic Variation; D007515:Islets of Langerhans / Q000166:cytology / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D004247:DNA