表达猪瘟病毒石门株E0基因重组鸡痘病毒的构建及动物免疫试验

Construction of Recombinant Fowlpox Virus Expressing E0 Gene of Classical Swine Fever Virus Shimen Strain and the Animal Immunity Experiment

应用PCR从质粒pMD18-T-E0中扩增编码CSFVE0蛋白的基因片段,定向克隆到重组鸡痘病毒表达载体FPV-P11上,进一步构建出重组鸡痘病毒转移载体FPV-pSY-E0。用脂质体将该质粒转染至鸡痘病毒感染的鸡胚成纤维细胞(CEF)后,通过蓝斑纯化实验筛选出重组鸡痘病毒FV282-CSFV-E0。PCR证实E0基因已整合至鸡痘病毒基因组中,Western blot检测到重组病毒感染CEF细胞中E0蛋白的表达。重组病毒3次腹腔接种小鼠,ELISA检测血清抗体滴度高达1:4096。重组病毒免疫猪3次之后,接种猪瘟病毒强毒进行攻毒试验,结果对免疫组产生75%的保护率,为研制猪瘟活载体疫苗奠定了基础。

The CSFV E0 gene was amplified from the plasmid pMD18-T-E0 by PCR and cloned into the FPV-Pll and FPV-pSY. The identified recombinant DNA was transfected into chicken embryo fibroblasts （CEF）to package Fowlpox virus. E0 gene was confirmed to be integrated into the genome of recombinant Fowlpox virus by PCR, and Western blot was employed for detection of E0 expression in the chicken embryo fibroblasts infected with recombinant Fowlpox virus . The results of ELISA showed that systemic immune response to CSFV could be induced effectively after the mice were immunized three times with recombinant Fowlpox virus through celiac route, the titer of antibody was 1 ： 4096. The protection experiment showed that 75% of piglets immunized three times with recombinant Fowlpox virus were survived, indicating that the recombinant Fowlpox virus was effective. This paper lays foundation for the study of CSFV live vector vaccine.