Dual overlapping peptides recognized by insulin peptide B:9-23 T cell receptor AV13S3 T cell clones of the NOD mouse.
T cells isolated from islets of non-obese diabetic (NOD) mice are enriched for insulin-reactive cells. The great majority of these T cells recognize insulin B chain peptide (B:9-23). B:9-23 reactive T cell clones are diabetogenic and show a dramatic TCR alpha -chain restriction (predominant AV13S3). We have studied the reactivity of five different B:9-23 reactive T cell clones to truncated peptides and alanine substituted analogues of B:9-23. Amongst these AV13S3 T cell clones, one reacted with peptide B:9-16 and four with B:13-23. The two peptides have in common only four amino acids (B:13-16; EALY). Having defined minimal peptide epitopes, we evaluated a mutant insulin sequence (B:13 glutamine) which retains metabolic activity. As predicted, this single amino acid change abrogated T cell reactivity. In addition, we have created a modified I-A(g7)gene with the B:9-23 peptide covalently linked to I-A(g7). Antigen presenting cells transfected with this construct were excellent presenting cells for all clones studied. The definition of dual peptide motifs and creation of bioactive covalent I-A(g7)-B:9-23 should facilitate studies of the pathogenic significance and antigen recognition by B:9-23 reactive diabetogenic T cells.
Abiru
N
N
Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
Wegmann
D
D
Kawasaki
E
E
Gottlieb
P
P
Simone
E
E
Eisenbarth
G S
GS
D000409:Alanine / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D017951:Antigen Presentation; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005973:Glutamine / Q000235:genetics / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology; D007328:Insulin / Q000235:genetics / Q000276:immunology*; D007515:Islets of Langerhans / Q000166:cytology; D051379:Mice; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; C407099:I-A g7 antigen; D007328:Insulin; D010446:Peptide Fragments; D010455:Peptides; D016693:Receptors, Antigen, T-Cell, alpha-beta; C097877:insulin B (9-23); D005973:Glutamine; D000409:Alanine