嵌合猪圆环病毒PCV1-2的构建及其感染性初步鉴定

Construction of molecular clone of chimeric porcine circovirus(PCV1-2) and identification of its infectivity

猪Ⅱ型圆环病毒(PCV2)是当前严重危害养猪业的重要病原之一。目前,世界上还没有有效疫苗用于该病毒的免疫预防。该研究利用PCR方法,将PCV2的ORF2基因替换猪Ⅰ型圆环病毒(PCV1)的ORF2基因,构建了以PCV1基因组为骨架的嵌合病毒(PCV1-2)分子克隆(pSK2PCV1-2)。将该分子克隆转染PK-15细胞并连续盲传5代,用RT-PCR方法可以在转染后盲传的细胞中检测到PCV1的ORF1 mRNA和PCV2的ORF2 mRNA,但检测不到PCV1的ORF2 mRNA和PCV2的ORF1 mRNA。间接免疫荧光检测显示在盲传第5代的细胞中有PCV2 ORF2蛋白的表达,表达蛋白主要分布于细胞核。该研究初步证实构建的PCV1-2分子克隆转染细胞后可以形成具有感染性的嵌合病毒,从而为更深入研究嵌合病毒生物学特性奠定了基础。

Porcine circovirus type 2（PCV2） recently emerged as an important infectious pathogen for pigs in the world. Unfortunately, there is no efficient method to deal with PCV2 infection until now. In this study, chimeric porcine circovirus molecular clone （pSK2PCV1-2） was constructed by cloning capsid gene of PCV2 into the backbone of PCV1. PK-15 ceils was transfected with pSK2PCV1-2 and then cultivated in plate for five passages, mRNA of PCVI ORFI and PCV2 ORF2 were detected in the fifth passage, but mRNA of PCV1 ORF2 and PCV2 ORFI were not detected in the ceils. On the other hand, capsid protein of PCV2 was also detected in the nucleolus of transfected cells by IIF. This study indicated that pSK2PCV1-2 could form infectious virus in transfected ceils. It will provide base for further study on biological characteristic of chimeric porcine circovirus.