Distinct epitopes are recognized by cytolytic T lymphocyte clones on the same class I molecule: direct demonstration using DNA-transfected targets and long-term cytolytic T cell clones.
By producing long-term, stable, cytolytic T lymphocyte clones and utilizing targets expressing only a single gene product derived from the stimulator mouse strain, we have been able to directly demonstrate that T cells recognize distinct epitopes expressed on a single H-2 molecule. These multiple determinants are distinguishable by inhibition patterns with monoclonal antibodies (mAb). When two T cell clones, P-2.14 and P-2.17, are tested on an L cell transfected with the Dp gene (lambda 12a), the T cells kill the transfected targets as well as blasts derived from Dp mouse strains. mAb 7-16.10 inhibits recognition and killing of Dp targets by both P-2.14 and P-2.17. This mAb recognizes a private specificity H-2.m22. Interestingly mAb 11-20.3 which also recognizes the H-2.m22 specificity inhibits clone P-2.14 but not P-2.17. The mAb 7-16.10, however, competes with 11-20.3 for binding to the surface of L cells expressing the Dp gene. Thus the two T cells must recognize an overlapping specificity. Other mAb which bind to the H-2Dp molecule are unable to inhibit either of these two cytolytic T cell clones. Paradoxically, any of the mAb when tested individually are sufficient to inhibit the polyclonal response derived from in vitro mixed lymphocyte culture. Therefore, by using targets expressing only a single H-2 molecule derived by DNA-mediated gene transfer and cytolytic T cell clones we have been able to directly demonstrate the presence of multiple epitopes on a single molecule and define their inhibition with mAb directed to that same molecule.
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis; D002460:Cell Line; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D004247:DNA / Q000235:genetics*; D000939:Epitopes / Q000032:analysis*; D006183:H-2 Antigens / Q000235:genetics; D007106:Immune Sera; D007376:Interleukin-2 / Q000302:isolation & purification; D007700:Kinetics; D007739:L Cells / Q000276:immunology; D051379:Mice; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D006183:H-2 Antigens; D007106:Immune Sera; D007376:Interleukin-2; D004247:DNA