Effect of bacterial vaccine on anti-tumor immunity and cisplatin-suppressed functional activity of mononuclers

Effect of bacterial vaccine Immunovak-VP-4 on metastasis development in C56B1/6 mice implanted with Lewis lung carcinoma was evaluated. Immunovak-VP-4 at a dose of 400 mkg was injected intraperitoneally according to 3 regimens: 1) 7, 5 and 3 days before tumor implantation; 2) 0,1, 3 and 5 days after tumor implantation; 3) 7, 5 and 3 days before implantation and 0,1, 3 and 5 days after tumor implantation. Administration of the 1-st and the 3-rd regimens produced 2- and 1.7-fold reductions in the number of animals with metastases, and 5.6-and 4.8-fold reductions in the number of metastases, respectively. When Immunovak-VP-4 was combined with cyclophosphane, life time of mice was 1.19-1.37 times longer as compared to the control doses of cyclophosphane. Life time prolongation correlated with the reduction in the number of lung metastases. Immunovak-VP-4 protected peripheral blood mononuclears against toxic effect of cytostatic agent, showing not only immunosupression disappearance, but also enhancement of functional activity of peripheral blood mononuclears. Thus, polycomponent vaccine Immunovak-VP-4, having immunomodulating properties and carrying various combinations of PAMPs through their interraction with TLR, results in the enhancement of antitumor immunity by means of increase and/or recovery of effector mechanisms of inherent immunity (likely, mainly NK-mediated cytotoxicity) and modification of other biological aspects of interaction between the host and the tumor.