发热伴血小板减少综合征病毒感染人源巨噬细胞形成包涵体结构

Inclusion Bodies are Formed in SFTSV-infected Human Macrophages

发热伴血小板减少综合征病毒(Severe fever with thrombocytopenia syndrome virus,SFTSV)是在我国首次发现的布尼亚病毒科白蛉病毒属的一种新型病毒,是新发传染病发热伴血小板减少综合征的致病病原。本研究通过免疫荧光共聚焦实验观察不同感染剂量和不同感染时相SFTSV核衣壳蛋白(Nucleocapsid protein,NP)在THP-1细胞内的动态定位特点,并应用电镜方法在超微结构水平观察不同感染时相THP-1细胞的胞内形态结构特征,发现SFTSV感染THP-1在胞内形成包涵体结构。研究进一步显示感染后的第3天核衣壳蛋白NP所形成包涵体的形态大小与感染后第7天培养上清中的病毒载量之间存在相关。本研究揭示SFTSV感染人源巨噬细胞THP-1形成的包涵体结构可能是SFTSV利用宿主细胞形成的特殊胞内结构以利于大量合成和产生新的病毒颗粒。

The severe fever with thrombocytopenia syndrome virus（SFTSV）is a new member in the genus Phlebovirus of the family Bunyaviridae identified in China.The SFTSV is also the causative pathogen of an emerging infectious disease：severe fever with thrombocytopenia syndrome.Using immunofluorescent staining and confocal microscopy,the intracellular distribution of nucleocapsid protein（NP）in SFTSV-infected THP-1cells was investigated with serial doses of SFTSV at different times after infection.Transmission electron microscopy was used to observe the ultrafine intracellular structure of SFTSV-infected THP-1cells at different times after infection.SFTSV NP could form intracellular inclusion bodies in infected THP-1cells.The association between NP-formed inclusion bodies and virus production was analyzed：the size of the inclusion body formed 3days after infection was correlated with the viral load in supernatants collected 7days after infection.These findings suggest that the inclusion bodies formed in SFTSV-infected THP-1cells could be where the SFTSV uses host-cell proteins and intracellular organelles to produce new viral particles.