THE DETECTION OF A BREAST-CANCER ANTIGEN ON MCF-7 CELLS REACTIVE WITHTHE TCR(ALPHA) OF A SPECIFIC KILLER T-CELL LINE

We established several immortalized human T cell lines by cotransfecti ng primary lymphocytes derived from breast cancer patients with human c-myc and human c-Ha-ras oncogenes. A CD8 positive (CD8+) killer T cel l line, FT-8, exhibited in vitro specific cytotoxicity to a human brea st cancer cell line, MCF-7. The FT-8 cells suppressed the growth of MC F-7 cells transplanted to athymic mice. The cytotoxic reaction was cau sed via T cell antigen receptor (TCR) on MCF-7 cells, because monoclon al 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. Th e TCR(alpha) protein recognized a target antigen of 32 KDa on MCF-7 ce lls.