DR beta peptides block the antigen-specific response but not the alloresponse of a dual-reactive T-cell clone.
It is generally assumed that alloreactivity and the response to foreign antigens are equivalent T-cell recognition events. We have addressed this issue by examining the antigen presentation of beef insulin by two DR1-restricted human T-clones. One of the clones was dual-reactive and exhibited alloreactivity. By employing 20 synthetic consecutive overlapping peptides representing the entire extracellular (residues 1-198) and intracellular (residues 222-273) parts of the DR2 beta molecule, the effects of each of these peptides on antigen presentation and alloreactivity were examined. The DR1-restricted response to beef insulin by both clones was inhibited by peptides from DR2 beta region 1-25. Other DR2 beta (residues 21-198 en 222-237) or control peptides had no effect. The DR3-associated alloresponse of the dual-reactive clone was not inhibited by any peptide. These observations suggest that recognition of antigen is fundamentally different from allorecognition.
Department of Microbiology, Baylor College of Medicine, Houston, TX 77030.
R G
RG
Ulrich
J W
JW
Thomas
G G
GG
Miller
M Z
MZ
Atassi
D000595:Amino Acid Sequence; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D002417:Cattle; D002999:Clone Cells; D000939:Epitopes / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology*; D006801:Humans; D007328:Insulin / Q000276:immunology; D007519:Isoantigens / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D006684:HLA-DR Antigens; D007328:Insulin; D007519:Isoantigens; D010455:Peptides