伪狂犬病病毒变异株EP0基因缺失株的构建及其致病力评价

Construction of EP0 gene knockout mutant of pseudorabies virus and its pathogenicity evaluation

EP0(Early Protein 0)基因是伪狂犬病病毒(PRV)早期表达的转录激活因子,可以结合并激活多种病毒基因启动子,调节基因的表达,同时其也是毒力相关基因。为探究EP0基因对PRV变异株毒力的影响,本研究采用CRISPR/Cas9系统敲除PRV变异株HeN1的EP0基因,通过噬斑纯化筛选与基因测序鉴定,成功构建1株EP0基因缺失病毒株PRV-EP0。小鼠毒力试验显示PRV-EP0株虽然体外复制能力降低,但其致病力与野生病毒株HeN1相比并无变化。本研究构建的EP0基因敲除病毒为研究PRV变异株EP0的功能奠定基础。

EP0 （Early Protein 0） gene is an early expression gene of PRV, and it works as a transcription activator, which can bind and activate a variety of virus gene promoter to regulate gene expression. At the same time, EP0 gene is also a virulence related gene. To explore whether EP0 is a virulence gene in variant strain, an EP0 knockout strain PRV-EP0 was constructed by CRISPR/Cas9 system, and the virulence of PRV-EP0 was evaluated in mice. The results showed that the replication capacity of PRV-EP0 strain was significantly decreased, however, the pathogenicity was not attenuated when compared with the wild type HEN1. In this study, EP0 knockout strain was a useful tool for studying the function of EP0.