重组传染性法氏囊病病毒VP2/VP243基因表达及保护性和免疫原性

目的在重组鸡痘病毒中表达传染性法氏囊病毒 VP2/VP243基因,并研究表达产物的保护性和免 疫原性。方法以 FPV 282E_4株 TK基因为侧翼,分别将鸡法氏囊病病毒(Infectious Bursal Disease Virus,IBDV) VP2 和VP243目的基因克隆到牛痘病毒A型包涵体(ATI)和痘苗病毒P7.5复合型启动子下游,构建成2个重组表达质 粒,命名为pUTALacVP和pUTA LacVPO。用这2个质粒转染CEF细胞,用X-gal染色法筛选出2株重组病毒vUTA lacVP2和 vUTALacVP0。用这 2株病毒免疫 1周龄 SPF鸡,以常规疫苗为对照。结果 ELISA、SDS-PAGE和 Western blot表明表达产物可与IBDV特异性多克隆抗体反应,并诱导鸡保护性抗体。在使用vvIBDV攻击前,对照组抗体水 平显著高于实验组。但攻击5 d后,实验组抗体水平明显升高。结论vUTALacVP2和 VPO在 CEF细胞中实现了高 效表达,但重组疫苗的保护率低于常规疫苗。

Expression of Recombinant Infectious Bursal Disease Virus (IBDV) VP2/VP243 Gene and Protection and Immunogenicity of Expressed Product

Objective To express IBDV VP2/VP243 gene in recombinant FPV and study on the protection and immunogenicity of expressed product. Methods Two recombinant plasmids, pUTALacVP2 and pUTAlacVP0,were constructed by inserting VP243 and VP2 genes of IBDV double strand genome fragment A to the downstream of hybrid promoter of cowlpox virus inclusion body type A(ATI) and vaccinia virus early promoter p7. 5 respectively. CEF cells were transfected with the 2 plasmids, and 2 kinds of recombinant virus- es, vUTALacVP2 and vUTAlacVP0, were screened out by X-gal staining. Then the 2 kinds of viruses were used for immunizing SPF chickens aged 1 week, using routine vaccine as control. Results ELISA, SDS-PAGE and Western blot demonstrated that the expressed products could reacted with specific PcAbs to IBDV and induce protective antibodies in chickens. Before challenge with vvIBDV, the antibody level in control group were signif- icantly higher than that in experimental group. However, the level in experimental group was increased rapidly 5d after challenge. Conclusion Two kinds of rFPV, vUTALac VP2 and VP0, were highly expressed in CEF cells. However, the protective rates of the recombinant viruses were lower than that of routine vaccine.