猪圆环病毒2与宿主细胞骨架蛋白相互作用的分子机制

Porcine circovirus 2 (PCV2) infection is an emerging and severe infectious disease in pig industry. Up to now the understanding pathogenesis was a basic and unsolved front scientific problem when designed a control program of PCV2 infection.In forthcoming study, based on the reported and published results of PCV2-infected cellular proteomics and PCV2 Cap protein binding to microtubule protein from a NSFC-supported distinguished youth project managed by me, using the monoclonal antibodies to PCV2-encoded proteins as tools, by some techniques including proteomics，virology, molecular biology, gene engineering, molecular cell biology as well as biochemistry, we shall try to identify interaction networks of PCV2 and cytoskeletonal proteins, to localize the fine functional domain of PCV2 Cap protein bound to microtubule protein and to analyse the interaction between PCV2-encoded proteins and host microtubule, microfilament and motor proteins as well as signal tranduction pathway, to uncover molecular mechanism that PCV2 replication regulates cytoskeleton networks.The forthcoming research data will provides an important clue to further study of PCV2 pathogenesis, to design the high efficacy vaccines against PCV2 and anti-PCV2 drugs.

猪圆环病毒2（PCV2）感染是新出现的、对养猪危害严重的传染病。致病机制不明是PCV2控制技术研究亟待解决的前沿基础科学问题。本课题拟在已结题的国家杰出青年基金项目基础上，以我们获得的PCV2感染细胞蛋白质组、PCV2 Cap蛋白与细胞alpha-tubulin相互作用信息为基础，以我们研制的针对PCV2编码蛋白的单克隆抗体为工具，借助病毒学、蛋白组学、分子生物学、细胞生物学、生物化学等技术，鉴定与揭示PCV2感染细胞骨架的精细蛋白质组动态，定位PCV2 Cap蛋白与alpha-tubulin互作的功能域，分析PCV2在复制过程中其编码蛋白与细胞骨架微丝、微管、motor蛋白相互作用及信号转导通路，解析PCV2复制调控细胞骨架的分子机制，为深入研究PCV2的致病机理、设计高效疫苗和药物设计研究提供理论基础。研究结果具有重要理论意义和应用价值。

猪圆环病毒病是新出现的、以免疫系统受损和抵抗力下降为特征的重要猪传染病，对养猪业的危害极大。猪圆环病毒2型是猪圆环病毒病的病原因子，揭示猪圆环病毒2型的细胞生物学特征与规律是猪圆环病毒病防控技术及产品开发的前沿理论问题。项目以细胞为模型，通过研究，发现并证明了猪圆环病毒2型衣壳蛋白通过促进细胞微管聚合助力病毒复制的机制，发现并证明了猪圆环病毒2型借助其衣壳与细胞微管Motor的动力蛋白亚基IC1结合沿微管从细胞膜向细胞核滑动的运动轨迹。鉴定了猪圆环病毒2型ORF3蛋白的出核信号序列，揭示了ORF3蛋白在PCV2复制中的角色。发现并鉴定了猪圆环病毒2型的一个新的编码蛋白ORF4，在此基础上，发现并证明了猪圆环病毒2型ORF4蛋白通过结合细胞线粒体ANT3蛋白促进线粒体凋亡的机制。解析出猪圆环病毒2型病毒粒子的冷冻电镜结构，证明PCV2与猪瘟病毒共栖息一个细胞能显著抑制猪瘟病毒的复制。这些研究结果在一定程度上揭示猪圆环病毒2型在感染过程中的细胞生物学特征，阐明了猪圆环病毒2型诱导细胞凋亡的分子致病机制。