HLA-A3 restricted mutant ras specific cytotoxic T-lymphocytes induced by vaccination with T-helper epitopes.
Cytotoxic T-lymphocytes are one of the most important elements of the antitumor defense. Stimulation of cytotoxic T-lymphocytes outgrowth after immunization with mutant ras peptides is a desired goal since these cells may kill tumor cells in vivo. In this study we tested responding peripheral mononuclear cells from a patient with pancreatic adenocarcinoma who had received intradermal peptide vaccination with a mixture of 17-mer mutant ras peptides and granulocyte-macrophage colony-stimulating factor as an adjuvant. Responding peripheral T-cells were cloned by limiting dilution and several CD8(+) cytotoxic T-lymphocytes, specific for the K- RAS 12-Cys mutation were obtained. By using a panel of nonamer peptides containing the 12-Cys mutation and covering position 4-21 in the ras molecule, the 9-mer peptide which was actually recognized by the cytotoxic T-lymphocytes could be identified. HLA-A*0302 could be identified as the antigen-presenting molecule, and the amino acid sequence of the T-cell epitope carries the previously identified HLA-A*0302 binding motif. The nonamer peptide was contained within the vaccine peptide originally used for intradermal immunization of the patient. The cytotoxic T-lymphocytes were capable of killing target cells expressing HLA-A*0302 that coexpressed the K- RAS 12-Cys mutation after transfection. These data demonstrate that the peptide used for vaccination (17-mer) is processed and presented in vivo, and that generation of cytotoxic T-lymphocytes by vaccination with T-helper epitopes may be important for further development of specific immunotherapy of cancer patients.
Gjertsen
Marianne Klemp
MK
Section for Immunotherapy, Department of Immunology, Norwegian Radium Hospital, University of Oslo, Montebello, 0310 Oslo, Norway. m.k.gjertsen@labmed.uio.no
Saeterdal
Ingvil
I
Saebøe-Larssen
Stein
S
Gaudernack
Gustav
G
D000230:Adenocarcinoma / Q000276:immunology; D000328:Adult; D017951:Antigen Presentation; D000951:Antigens, Neoplasm / Q000276:immunology; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use*; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D005260:Female; D011905:Genes, ras; D015791:HLA-A3 Antigen / Q000276:immunology*; D006801:Humans; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000276:immunology / Q000628:therapy; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology / Q000627:therapeutic use; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D016896:Treatment Outcome; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology / Q000627:therapeutic use*
D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D000939:Epitopes; D015791:HLA-A3 Antigen; D010446:Peptide Fragments; D014614:Vaccines, Synthetic; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)