Cytotoxic T lymphocyte clone specific for autologous human hepatocellular carcinoma cell line SUHC-1

We established a cytotoxic T lymphocyte (CTL) clone directed against an autologous hepatocellular carcinoma (HCC) cell line SUHC-1 which had been established in our department from a patient with HCC associated with hepatitis C virus infection. The CTL clone lysed autologous SUHC-1 cells but did not lyse autologous Epstein-Barr (EB) virus-transformed B cells, natural killer (NK) cell-sensitive erythroleukaemia cell line K562, the NK-resistant B cell line Daudi, or allogeneic HCC cell lines, Hep-G2, Hep-3B, Mahlavu and PLC/PRF/5. The CTL clone expressed CD3 and CD8 molecules. The cytotoxic activity of the clone was inhibited by anti-CD3, anti-CD8 and antihistocompatibility antigen (HLA) class I monoclonal antibodies. These results indicated that the CTL clone-recognized HCC tumour antigen in an HLA class I-restricted manner. Furthermore, we investigated the T cell receptor (TCR) gene usage of the CTL clone. The CTL clone expressed TCR alpha beta. We searched for expression of TCR variable (V) alpha and beta regions and sequenced complementary determining region (CDR) 3 of the clone. The clone expressed V alpha 14, junctional (J) region alpha 9.7 and V beta 7, J beta 2.1. The amino acid sequence of the N region of the alpha chain was S-P-G-G-G-G-A-D-G-L-T and of the N-D-N region of the beta chain was S-W-T-G-A-S-T-D-T-Q-Y. These results suggested that HLA class I-restricted CTL play an important role in the elimination of human HCC cells.