[Study of local application of CpG-oligodeoxynucleotide combined with 4-1BB monoclonal antibody to treat hepatoma- bearing mice].

Objective To investigate the curative effect of local application of CpG-oligodeoxynucleotide (CpG-ODN) combined with 4-1BB monoclonal antibody in hepatoma-bearing mice, and to evaluate the effect of 4-1BB monoclonal antibody on CpG-ODN immunotherapy. Methods H22 single cell suspension was injected subcutaneously into the axilla and four limbs of the BALB/c male mice to establish a tumor-bearing mice model. After 7 days, 30 mice with corresponding tumor-bearing volume were screened and randomly divided into model control group, CpG group and CpG+4-1BB group, and the drug was injected into the tumors of left lower extremity. The same batch of normal mice was selected as normal control group. Survival of mice was recorded. Tumor-bearing volume and organ index were calculated. Serum levels of interleukin (IL) - 12 and interferon (IFN) gamma and spleen CD8+T lymphocyte ratio were measured. The measurement data were analyzed by analysis of variance. The survival rate of each group of mice was analyzed by log-rank test. Results Mice in the model control group with tumor-bearing volume had a sustained growth before the execution. CpG group and the CpG+4-1BB group [(976.08 ± 29.55) mm3, (47.25 ± 0.93) mm3)] tumor-bearing volume was decreased than model group [(1 336.52 ± 39.40) mm3] (F = 5 329.273, P 0.05). Serum IL-12 concentration (23.90 ± 2.33 pg/ml), IFN-γ concentration (103.02 ± 6.10 pg/ml) and spleen CD8+T cell ratio (4.54 ± 0.62%) in the model group were lower than those in the normal group (P 0.05). There was no significant difference in organ index between the four groups (P > 0.05). Conclusion 4-1BB monoclonal antibody combined with CpG-ODN therapy can shrink hepatoma-bearing capacity, inhibit the growth of distant tumors and significantly prolong the survival time of mice. Key words: Carcinoma, hepatocellular; Immunotherapy; Remote tumor; 4-1BB; CpG oligodeoxynucleotide