CYTOTOXIC T-LYMPHOCYTES RECOGNIZE TUMOR-ANTIGENS OF A MURINE COLONIC-CARCINOMA BY USING DIFFERENT T-CELL RECEPTORS

To see whether different antigens expressed by the same tumor are reco gnized by distinct T-cell receptors (TCR), we used cytotoxic T-lymphoc yte (CTL) lines known to lyse in vitro the syngeneic BALB/c adenocarci noma C-26. Four of these CD3(+) CD8(+) lines showed 4 different patter ns of lysis on a panel of MHC-class-I-compatible targets. The activity was H-2(d)-restricted and could be blocked by anti-CD3 and anti-TCR-a lpha/beta monoclonal antibodies (MAbs). The CTL lines were also effect ive, although to a different extent, in adoptive immunotherapy of mice bearing lung metastases. Phenotypic analysis revealed in all the line s a high frequency of cells positive for CD45, asialo GMI (ASGM I), ly mphocyte-function-associated antigen-I (LFA-I), intercellular adhesion molecule-I (ICAM-I) and CD44, but negligible expression of L-selectin (LAM-I) and very late antigen-4 (VLA-4); 2 lines expressed the vitron ectin-receptor (VN-R). Analysis of TCR VB-chains used by the 4 lines s howed selective presence of V beta 6, V beta 8.2, V beta 8.3 and of V beta 13 chains. MAbs directed to these VB chains blocked their lytic a ctivity in vitro. V alpha-chain transcripts of the lines were identifi ed by polymerase chain reaction (PCR) as V alpha ITTII and V alpha 52 in 2 lines, while one could not be identified. Analysis of V beta s in mixed lymphocyte-tumor-cell cultures (MLTC) of T cells deriving from tumor-infiltrating lymphocytes (TIL) or from spleen of C-26 tumor-bear ing or immune animals indicated that the TCR of the CTL lines were rep resentatives of the TCR repertoire recognizing C-26 tumor, since their V beta s were shown to be selectively expanded in MLTC.(C) 1994 Wiley -Liss, Inc.