口蹄疫病毒重组鸡痘病毒活载体疫苗和DNA疫苗免疫牛的试验研究

Immune Responses in Cattle Induced by Recombinant Fowl-pox Virus and DNA Vaccine against Foot-and-mouth Disease Virus

将本课题组构建的共表达FMDV衣壳蛋白前体P1-2A基因以及蛋白酶3C基因的重组鸡痘病毒活载体疫苗vUTAL3CP1以及共表达P1-2A和猪白介素18基因的重组DNA疫苗(pVIRIL18P1),分别以单独及混合的共3种方式接种牛,然后通过间接ELISA、中和试验和T淋巴细胞增殖试验评价其诱导的特异性体液和细胞免疫水平。结果表明这2种基因工程疫苗均能诱导牛产生特异性的体液及细胞免疫应答。其中重组鸡痘病毒vUTAL3CP1免疫组以及联合免疫组(vUTAL3CP1/pVIRIL18P1,pVIRIL18P1/vUTAL3CP1)诱导的中和抗体滴度分别达到1∶64、1∶64和1∶54,已接近于常规灭活疫苗水平(1∶90),而特异性的T淋巴细胞增殖反应则比后者高得多(P<0.01)。该研究结果为进一步进行免疫攻毒试验,并最终筛选出最佳疫苗和免疫程序奠定了基础。

The recombinant fowl pox virus vUTAL3CP1 co-expressing FMDV P1-2A gene and 3C^pro gene and another rDNA vaccine plasmid pVIRIL18P1 co-expressing P1-2A gene and poIL-18 gene were constructed in our previous studies. In this study, cattle were inoculated intramuscularly using these 2 recombinant vaccines alone or in combination. And results of C-ELISA, VNT and lymphoproliferation assay indicated all of these recombinant vaccines could induce specific humoral and cellular immune responses against FMD. Compared with conventional inactivated vaccine, vaccination strategies of vUTAL3CP1, vUTAL3CP1 /pVIRIL18P1 and pVIRIL18P1/ vUTAL3CP1, could induce not only approximately the same FMDV antibody level （titre of neutralizing antibody were 1 ： 64, 1 ： 64, 1 ： 54 respectively, while inactivated vaccine was 1 ： 90）, but also higher cellular immune responses （P〈0.01）.