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. Melthods  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. Cytotoxicity against 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 level of reactivity against PC-9, an HLA-A0206-positive lung adenocarcinoma cell line. Conversely, anti-PC-9-specific CTL were inducible by multiple stimulations of RLNL with PC-9 cells in 2 of 3 patients. Conclusions  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.