FUNCTIONAL AND MOLECULAR ANALYSIS OF T-CELL RECEPTORS USED BY PANCREATIC-SPECIFIC AND BREAST TUMOR-SPECIFIC (MUCIN-)SPECIFIC CYTOTOXIC T-CELLS

We have previously reported that tumor-specific cytotoxic T lymphocyte s (CTLs) derived from pancreatic and breast cancer patients recognize specific epitopes on the mucin polypeptide core, These CTLs recognize breast and pancreatic tumor cells in a major histocompatibility comple x (MHC)-unrestrictrd fashion, and the lytic activity of these T cells is mediated through die T cell receptor (TCR). To characterize the TCR -mediated MHC-unrestricted CTL function, we used semiquantitative poly merase chain reaction (PCR) and cytofluorometry to analyze the TCR rep ertoire in CTL lines established from cancer patients and specific for mucin-expressing tumors. We found three TCR V beta genes, V beta 9, V beta 13.1, and V beta 17, predominantly expressed in these functional cell lines, established either from one patient by stimulation with v arious mucin-expressing targets or from different patients. Sequencing of these pref erentially used TCR gents unveiled usage of distinct J beta and C beta but a potentially interesting conservation of certain amino acids in the CDR3 region.