小鼠肥大细胞瘤基因疫苗的免疫治疗作用研究

Immune effect of tumor gene vaccine containing mouse mastocytoma tumor specific gene P1A in mice

目的 探讨α 病毒RNA复制酶对基因疫苗的免疫学效应的加强作用 ,寻找更好的基因疫苗形式。方法 将小鼠肥大细胞瘤P815的肿瘤特异抗原P1A基因克隆到含SFV的RNA复制酶的真核表达载体pSMART2a中 ,以此作为肿瘤基因疫苗 ,观察该疫苗对P815种植瘤的防治作用、特异细胞毒T淋巴细胞激活和抗体的生成情况。结果 该重组基因疫苗在体外有很好的表达 ,注射后CTL的最大杀伤效率为 60 % ,而普通载体疫苗形式pCI neo P1A则只有 40 %的杀伤活性 ;在观察期限内 ,前者的动物成瘤率和动物生存率分别为 2 0 %和 40 % ,后者则分别为 60 %和 2 0 %。两种情况下都不能检测到任何特异抗体的产生。结论 α 病毒RNA复制酶对基因疫苗的免疫学效应有加强作用。

Objective To explore the enhancing effect of RNA replicase of alpha virus on the immune effect of genetic vaccine in order to obtain its optimal form. Methods Tumor specific P1A gene of mouse mastocytoma was cloned into eukaryotic expression vector pSMART2a containing RNA replicase of SFV. These recombinants were used as tumor genetic vaccines for tumor loaded mice induced by mastocytoma cell line P815 and their anti tumor effect was observed. The elicited specific CTL and antibodies were also studied. Results The recombinant genetic vaccine expressed well in vitro. The maximal primed specific CTL by the vaccine reached 60%, whereas the maximal CTL primed by normal genetic vaccine pCI neo/P1A only reached 40%. Meanwhile, the rate of tumor incidence and animal survival during the experiment for the former were 20% and 40% respectively, but those of the latter were separately 60% and 20%. No specific antibody was detected in the mice inoculated with pSMART2a/P1A or pCI neo/P1A. Conclusion RNA replicase of alpha-virus has strong immunological effect on tumor genetic vaccines.