HER2/neu-derived Peptides Are Shared Antigens among Human Non-Small Cell Lung Cancer and Ovarian Cancer

Previously, we have reported a correlation between the expression of HER2lneu and sensitivity to HLA-A2-restricted cytotoxic T-cells (CTL) in ovarian cancer. To investigate the role of HER2lneu in human non-small cell lung cancer (NSCLC), we established autologous tumor-specific CTL from tumor-infiltrating lymphocytes of HLA-A2+ HER2/ ne NSCLC patients. These CTL lines specifically recognized HLA-A2+ HER2/neU+ autologous and allogeneic NSCLC cell lines as well as HLA-A2+ HER2/neU+ heterologous ovarian cancer cell lines. Furthermore, these CTL recognized an overexpressed, HER2/neu-derived peptide. From these results, we conclude that HLA-A2 serves as a restriction element in NSCLC. More importantly, at least one HER2/neu-derived peptide is a tumor-associated antigen in NSCLC and ovarian cancer.