The detection of a breast cancer antigen on MCF-7 cells reactive with the TCR (alpha) of a specific killer T cell line.

We established several immortalized human T cell lines by cotransfecting primary lymphocytes derived from breast cancer patients with human c-myc and human c-Ha-ras oncogenes. A CD8 positive (CD8+) killer T cell line, FT-8, exhibited in vitro specific cytotoxicity to a human breast cancer cell line, MCF-7. The FT-8 cells suppressed the growth of MCF-7 cells transplanted to athymic mice. The cytotoxic reaction was caused via T cell antigen receptor (TCR) on MCF-7 cells, because monoclonal antibodies against the TCR inhibited the cytotoxicity of FT-8 cells. The TCR (alpha) cDNA of FT-8 was cloned by using a PCR amplification technique and expressed by a cell-free in vitro translation system. The TCR (alpha) protein recognized a target antigen of 32 KDa on MCF-7 cells.