重组鸡痘病毒和DNA疫苗对口蹄疫病毒的豚鼠免疫保护

将构建的携带FMDV衣壳蛋白P1-2A和蛋白酶3C编码基因的重组鸡痘病毒活载体疫苗vUTAL3CP1以及编码FMDVP1-2A基因和猪IL-18基因的重组DNA疫苗pVIRIL18P1,分别以单独和混合的方式给豚鼠进行2次免疫,然后测定FMDV特异性结合抗体、中和抗体和T淋巴细胞增殖反应,并用250ID50的FMDV进行攻击,观察其保护效果。结果表明这2种基因工程疫苗均能诱导豚鼠产生特异性的体液免疫及细胞免疫应答。其中以vUTAL3CP1两次免疫组的效果最好,其诱导的抗体水平已接近于常规灭活疫苗,而细胞免疫水平则比后者高得多。攻击保护结果表明该组完全保护率可达3/4,而另外两组也具有一定保护效果。上述研究结果为进一步进行大动物免疫攻毒试验,并最终筛选出最佳疫苗和免疫程序奠定了基础。

Prophylaxtic Efficacy of Recombinant Fowl-pox Virus and DNA Vaccine Against Foot-and-Mouth Disease Virus in Guinea Pigs

A recombinant Fowlpox virus (vUTAL3CP1) containing FMDV capsid, P1-2A, and viral 3C protease coding regions,and another plasmid DNA (pVIRIL18P1) encoding P1-2A gene and swine interleukin-18 (IL-18) cDNA,were constructed. guinea pigs were inoculated intramuscularly twice at a 28-day interval with vUTAL3CP1 and pVIRIL18P1 alone, respectively, or vUTAL3CP1 priming and pVIRIL18P1 boosting. To evaluate the prophylaxtic efficacy of these vaccine candidates, anti-FMDV antibodies, neutralizing antibodies and T cell proliferation were detected. All of Guinea pigs were challenged with 250ID_{50} FMDV. The results indicated that both vaccines could elicit specific humoral immune and cellular immune responses. Compared with conventional inactivated vaccines, vUTAL3CP1 elicited not only similar FMDV antibody level but also stronger T cell proliferation. Three in four guinea pigs immunized by vUTAL3CP1 were protected completely from the FMDV infection, while other recombinant vaccines inoculated groups had much lower protection rate. The study provides valuable support for further virus challenge tests in pigs and cattle.