ANTITUMOR IMMUNITY AND VACCINE EFFECT INDUCED BY IL—12 SYNERGIZES B7—1 GENE TRANSFECTED CELLS

Cytokines play an crucial role in the induction of antitumor immunity. It have been demonstrated that cytokines such as IL-2, IL-4, IL-12 could stimulate immunity response in many basic and clinical experiment1-3]. Interleukin 12 (IL-12) is a heterodimeric cytokine which consists of p40 and p35 subunits. It stimulates the proliferation and activation of T lymphocyte and other killer cells and induces the production of IFN-g by these cells4, 5]. IL-12 promotes T helper type 1 responses.…

Antitumor immunity and vaccine effect induced by IL-12 synergizes B7-1 gene transfected cells

Objective: To study the synergic effects of IL-12 and B7-1 transfectant on antitumor immunity in vivo. Methods: The retrovirus vector encoding mIL-12 and mB7-1 gene was tranfected into EL-4 thymic lymphoma cells respectively.The cells were used as tumor vaccine and the therapeutic effect was observed. Results: In contrast to the miceimmunized with EL-4/Wt or EL-4/Neo groups, thetumorigenicity of EL-4/IL-12 transfectant was decreased(P<0.001). The EL-4/IL-12 and EL-4/B7-1 cells irradiatedwith 60Co showed significant systematic protective effectsagainst the rechallenge of EL-4/Wt. 60Co irradiatedEL-4/IL-12 cells delayed the occurrence of tumor andprolonged the survival period of tumor bearing mice.Combination of the vaccines of EL-4/IL-12 and EL-4/B7-1 resulted in the enhanced therapeutic effect compared witheach single transfectant group (P<0.001). Conclusion: The results showed that IL-12 transduced cells could enhancethe antitumor immunity of host as cancer vaccine.Combination of the EL-4/IL-12 and EL-4/B7-1 transfectant could improve immunity of host and is a prospect cancervaccine.