title: Cytotoxic T lymphocyte recognition of HLA-A/B antigens introduced into EL4 cells by cell-liposome fusion.
abstract: HLA-A2 and -B7 antigens were introduced into EL4 (H-2b) cells by cell-liposome fusion and were used as targets or stimulators for cytotoxic T lymphocytes (CTL) generated in C57B1/6 (H-2b) mice. It was found that such EL4-HLA cells were not recognized by CTL that had been raised against either a human cell line bearing these HLA antigens or the purified HLA-A2 and -B7 antigens reconstituted into liposomes. In addition, EL4-HLA cells were not capable of inducing CTL that could recognize a human cell line bearing HLA-A2 and -B7 antigens. Instead, EL4-HLA cells induced CTL that specifically lysed EL4-HLA cells and not human cells expressing HLA-A2 and -B7. CTL recognition required the presence of HLA antigens on the EL4 cell surface and was inhibited by antibodies against either H-2b or HLA-A/B. Monoclonal antibody binding studies showed that the expected polymorphic determinants of the HLA-A2 and -B7 antigens were still present on EL4-HLA cells. However, the specificity of CTL or their precursors that are capable of recognizing HLA-A2 or -B7 was altered after these antigens became associated with the EL4 surface. Possible explanations for these results are discussed.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology; D001666:Binding Sites, Antibody; D002459:Cell Fusion; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes; D006680:HLA Antigens / Q000276:immunology*; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006801:Humans; D008081:Liposomes / Q000276:immunology*; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013234:Stem Cells / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D008081:Liposomes