Objective To explore the significance of the combined strategy of oncolytic virus infection, immune effector cell supplement, and immune checkpoint blocking in the treatment of gastric cancer.

Methods A tumor-bearing nude mouse model of gastric cancer was treated with recombinant oncolytic vaccinia virus carrying the CXCL9 gene of T lymphocyte chemokine and IL-7gene (VV-IL7-CXCL9) obtained in previous experiments. We established a triple-intervention group of recombinant oncolytic vaccinia virus intratumoral injection+cytotoxic T lymphocyte (CTL)+immune checkpoint blocker (PD-1 monoclonal antibody), a single-intervention group of three measures, a dual-intervention group, and a blank control group. After the intervention, tumor-growth curve method, tumor-inhibition rate method, and bioluminescence method were used to detect the tumor treatment effect. ELISA was used to detect CXCL9 and IL-7 molecule concentration in the serum and tissue homogenate of animals in each group.

Results The therapeutic results of animal models showed that the tumor growth in the triple-intervention group of recombinant oncolytic poxvirus+CTL+immune checkpoint blocker (PD-1 monoclonal antibody) was significantly slower than those in the other intervention and the blank control group.

Conclusion The combination of recombinant oncolytic poxvirus intratumoral injection+CTL+immune checkpoint blocker (PD-1 monoclonal antibody) exert a strong antitumor effect in intervention experiments on gastric-cancer animal models.