In vitro generation of human cytolytic T-cells specific for peptides derived from the HER-2/neu protooncogene protein.
The development of T-cell therapy for the treatment of human malignancy has been hindered, in large part, by a lack of identifiable tumor antigens. Studies to identify potential T-cell targets in humans have been difficult because of practical problems limiting the use of in vivo immunization and a lack of reproducible in vitro priming methods. Oncogenic proteins are involved in malignant transformation and maintenance of the transformed phenotype and theoretically are potential targets to T-cell therapy. HER-2/neu protein is a protooncogene product overexpressed in a variety of human malignancies and is associated with malignant transformation and aggressive disease in human breast cancer. Previous studies have shown that some patients with breast cancer have existent helper/inducer T-cell immunity to p185HER-2/neu protein and peptides. The current study represents initial attempts to identify candidate cytotoxic T-lymphocyte (CTL) epitopes. Synthetic peptides were constructed identical to HER-2/neu protein segments with amino acid motifs similar to the published motif for HLA-2.1-binding peptides. Four peptides were synthesized and two were shown to be avid binders to HLA-A2.1. Two of the four peptides could be shown to elicit peptide-specific CTL by primary in vitro immunization in a culture system using peripheral blood lymphocytes from a normal individual homozygous for HLA-A2. p185HER-2/neu protooncogene protein contains immunogenic epitopes capable of generating human CD8+ CTL. The identification of candidate CTL epitopes will allow studies to determine whether some cancer patients have existent CTL immunity to HER-2/neu protein. The demonstrated ability to generate human peptide-specific CTL in vitro allows screening of other oncogenic proteins to identify candidate T-cell epitopes potentially useful for future immunotherapy studies.
Disis
M L
ML
Department of Medicine, University of Washington, Seattle 98195.
Smith
J W
JW
Murphy
A E
AE
Chen
W
W
Cheever
M A
MA
D000595:Amino Acid Sequence; D001665:Binding Sites; D000939:Epitopes; D066246:ErbB Receptors / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology; D007114:Immunization; D016219:Immunotherapy, Adoptive; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology*; D011518:Proto-Oncogene Proteins / Q000276:immunology*; D018719:Erb-b2 Receptor Tyrosine Kinases; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000502:physiology
D000939:Epitopes; D066246:ErbB Receptors; D015789:HLA-A2 Antigen; D010446:Peptide Fragments; D011518:Proto-Oncogene Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases