Induction of Tumor-Specific Cytotoxic T Lymphocytes from Regional Lymph Node Lymphocytes of Human Breast Cancer

BACKGROUND: In this study we activated breast cancer-specific cytotoxic T lymphocytes (CTL) from regional lymph node lymphocytes (RLNL) of HLA-A2-positive patients with breast cancer. METHODS: Freshly isolated RLNL were stimulated with solid phase anti-CD3 monoclonal antibody followed by expansion with recombinant interleukin-2. Subsequently, the RLNL were stimulated with an irradiated HLA 0201 breast cancer cell line,MCF-7, at a responder/stimulator ratio of 10/1 once a week for 2 weeks. RESULTS: The cultured RLNL exhibited specific lysis against MCF-7 in all 5 HLA-A2-positive patients tested, but not in 2 HLA-A2-negative patients. Cytotoxicityagainst MCF-7 was substantially inhibited by addition of anti-HLA-A2 mAb. In 3 of 5 HLA-A2-positive patients, anti-MCF-7 CTL also exhibited a substantial levelof reactivity against PC-9, an HLA-A0206-positive lung adenocarcinoma cell line. Conversely, anti -PC-9-specific CTL were inducible by multiple stimulations ofRLNL with PC-9 cells in 2 of 3 patients. CONCLUSION: These results suggest that several common tumor antigens might exist among HLA-A2-positive breast cancers, some of which may be shared with lung adenocarcinomas.