title: T-cell responses against products of oncogenes: generation and characterization of human T-cell clones specific for p21 ras-derived synthetic peptides.
abstract: Peptides derived from mutated human proto-oncogenes bound to HLA may represent a novel type of tumor-specific antigen. Mutated ras genes are the oncogenes most frequently identified in human cancer. The transforming genes carry a mutation in codons 12, 13, or 61. We have investigated whether the T-cell repertoire of healthy individuals contains T cells capable of recognizing and responding to oncogene-derived peptides. Synthetic peptides derived from mutated p21 ras proto-oncogenes, covering mutations at codons 12 or 13 were selected. It was feasible to elicit T-cell responses and isolate several new T-cell clones (TCC) with specificity for a number of different mutated ras peptides after repeated in vitro immunization. Four TCC were characterized with respect to fine specificity and HLA restriction. TCC B and I were restricted by HLA-DR molecules, and recognized the mutated p21 ras-derived peptide carrying Arg and Lys at residue 12, respectively. TCC E and F were restricted by HLA-DQ molecules, the former being specific for a mutated p21 ras-derived peptide with Val in position 13 and the latter more broadly reactive. Peptide competition experiments with a panel of ten peptides derived from p21 ras indicated that all could bind to HLA-DQ molecules of the T-cell donor, while several were also able to bind his HLA-DR molecules. These results show that several p21 ras mutations resulting in aa substitutions at residues 12 or 13 could be recognized by T cells derived from precursor T cells of relatively low frequency present in the normal repertoire of a single donor.
authors.affiliation: Institute of Transplantation Immunology, National Hospital, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Gedde-Dahl
authors.forename: J A
authors.initials: JA
authors.lastname: Eriksen
authors.forename: E
authors.initials: E
authors.lastname: Thorsby
authors.forename: G
authors.initials: G
authors.lastname: Gaudernack
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001666:Binding Sites, Antibody; D001667:Binding, Competitive; D002999:Clone Cells / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D010455:Peptides; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)