Immunological responses against an autologous human hepatocellular carcinoma cell line

Multiple courses of immunotherapy with different immune cell types for patients with hepatocellular carcinoma after microwave ablation

The aim of the present study was to investigate the therapeutic efficacy of immunotherapy after microwave ablation (MWA), which was used to improve liver function, reduce the recurrence rate and enhance survival period in patients with hepatocellular carcinoma (HCC). Between February 2009 and December 2010, 14 patients received immunotherapy after MWA (immunotherapy group) and 15 patients received MWA alone with no post-ablated adjuvant therapy (control group). Immune and liver parameters, recurrence rate and survival time were recorded. The absolute lymphocyte count in the immunotherapy group exceeded that in the control group after 3 courses of immunotherapy (P<0.05). No significant differences were detected in the lymphocyte subset distribution in the control and immunotherapy patients prior to ablation (P>0.05); however, certain cytotoxic subsets (CD3⁺/CD8⁺, CD8⁺CD28⁺ and CD3⁺CD16⁺CD56⁺ T cells) were over-represented and negative regulatory or helper subsets (CD4⁺CD8⁺, CD4⁺, CD4⁺CD25⁺) were under-represented in the immunotherapy group between 1 and 12 months after immunotherapy (P<0.05). After 2 courses of immunotherapy the proliferation rate of myeloid dendritic cells and T lymphocytes, including CD3⁺/CD8⁺ lymphocytes, significantly increased (P<0.05 and P<0.01, respectively). In addition, the level of albumin in the immunotherapy group exceeded that in the control group after 3 courses of immunotherapy (P<0.05). However, the rate of disease-free survival and overall survival within 16 months of MWA did not differ significantly between the two groups (P>0.05). In conclusion, the results of the present study indicate that immunotherapy improves the immune status and liver function of patients with HCC.

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 anti-histocompatibility 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 alphabeta. 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 alpha14, junctional (J) region alpha9.7 and V beta7, J beta2.1. The amino acid sequence of the N region of the of 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.

Augmented antitumor effects of killer cells induced by tumor necrosis factor gene-transduced autologous tumor cells from gastrointestinal cancer patients

The purpose of this study was to determine the feasibility of a vaccine therapy using tumor necrosis factor (TNF) gene-transduced autologous tumor cells for the treatment of human gastrointestinal cancers, which tend to have lower immunogenicity than other cancers such as melanoma and renal cell carcinoma. We succeeded in establishing primary cultured tumor cells from 12/54 carcinomatous effusions (4 liver cancer patients, 5 gastric cancer patients, 1 pancreatic cancer patient, and 2 colon cancer patients) and in transducing the TNF gene to the tumor cells by using the retrovirus vector MFG-TNF. Even after irradiation, TNF production (0.3-3.5 U/ml per 10(6) cells per 72 hr) was confirmed for 10 of 12 transfectants, and the other two transduced cells were found to have approximately one TNF gene copy. In 7 of the 12 patients, the cytotoxic activity of killer cells to nontransduced autologous tumor cells incubated with these TNF gene transfectants was augmented. This activity was blocked with anti-HLA class I antibody or BrefeldinA (BFA), suggesting that the killer cells were cytotoxic T lymphocytes (CTL) and tumor antigens are presented with HLA class I molecules. Indeed, enhanced expression of HLA class I and/or ICAM-1 molecules on the surface of the TNF gene-transduced tumor cells were observed by fluorescence-activated cell sorting (FACS) analysis. Furthermore, natural killer (NK) and/or lymphokine-activated killer (LAK) activities determined by using K562 or Daudi cells as targets were also enhanced in some of these cases when they were incubated with TNF gene-transduced tumor cells. These findings indicate the feasibility of using TNF gene-transduced tumor cells as a vaccine in gastrointestinal cancer patients.