Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China.
Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China.
J Virol. 2019 May 15;93(11). doi: 10.1128/JVI.02205-18. Print 2019 Jun 1.
Avian hepatitis E virus (HEV) is the main causative agent of big liver and spleen disease in chickens. Due to the absence of a highly effective cell culture system, there are few reports about the interaction between avian HEV and host cells. In this study, organic anion-transporting polypeptide 1A2 (OATP1A2) from chicken liver cells was identified to interact with ap237, a truncated avian HEV capsid protein spanning amino acids 313 to 549, by a glutathione -transferase (GST) pulldown assay. GST pulldown and indirect enzyme-linked immunosorbent assays (ELISAs) further confirmed that the extracellular domain of OATP1A2 directly binds with ap237. The expression levels of OATP1A2 in host cells are positively correlated with the amounts of ap237 attachment and virus infection. The distribution of OATP1A2 in different tissues is consistent with avian HEV infection Finally, when the functions of OATP1A2 in cells are inhibited by its substrates or an inhibitor or blocked by ap237 or anti-OATP1A2 sera, attachment to and infection of host cells by avian HEV are significantly reduced. Collectively, these results displayed for the first time that OATP1A2 interacts with the avian HEV capsid protein and can influence viral infection in host cells. The present study provides new insight to understand the process of avian HEV infection of host cells. The process of viral infection is centered around the interaction between the virus and host cells. Due to the lack of a highly effective cell culture system , there is little understanding about the interaction between avian HEV and its host cells. In this study, a total of seven host proteins were screened in chicken liver cells by a truncated avian HEV capsid protein (ap237) in which the host protein OATP1A2 interacted with ap237. Overexpression of OATP1A2 in the cells can promote ap237 adsorption as well as avian HEV adsorption and infection of the cells. When the function of OATP1A2 in cells was inhibited by substrates or inhibitors, attachment and infection by avian HEV significantly decreased. The distribution of OATP1A2 in different chicken tissues corresponded with that in tissues during avian HEV infection. This is the first finding that OATP1A2 is involved in viral infection of host cells.
禽戊型肝炎病毒（HEV）是导致鸡大肝大脾病的主要病原体。由于缺乏高效的细胞培养系统，关于禽 HEV 与宿主细胞相互作用的报道较少。本研究通过谷胱甘肽 S-转移酶（GST）下拉实验鉴定了来自鸡肝细胞的有机阴离子转运多肽 1A2（OATP1A2）与截断的禽 HEV 衣壳蛋白（ap237）相互作用，该蛋白跨越氨基酸 313 至 549 位。GST 下拉和间接酶联免疫吸附试验（ELISA）进一步证实，OATP1A2 的细胞外结构域直接与 ap237 结合。宿主细胞中 OATP1A2 的表达水平与 ap237 附着和病毒感染的量呈正相关。OATP1A2 在不同组织中的分布与禽 HEV 感染一致。最后，当细胞中 OATP1A2 的功能被其底物或抑制剂抑制，或被 ap237 或抗-OATP1A2 血清阻断时，禽 HEV 对宿主细胞的附着和感染显著减少。综上所述，这些结果首次表明 OATP1A2 与禽 HEV 衣壳蛋白相互作用，并能影响宿主细胞中的病毒感染。本研究为深入了解禽 HEV 感染宿主细胞的过程提供了新的见解。病毒感染的过程以病毒与宿主细胞的相互作用为中心。由于缺乏高效的细胞培养系统，对禽 HEV 与其宿主细胞的相互作用知之甚少。在本研究中，通过截断的禽 HEV 衣壳蛋白（ap237）在鸡肝细胞中筛选了总共 7 种宿主蛋白，发现宿主蛋白 OATP1A2 与 ap237 相互作用。细胞中 OATP1A2 的过表达可促进 ap237 吸附以及禽 HEV 吸附和感染细胞。当细胞中 OATP1A2 的功能被底物或抑制剂抑制时，禽 HEV 的附着和感染明显减少。OATP1A2 在不同鸡组织中的分布与禽 HEV 感染时的组织分布相对应。这是首次发现 OATP1A2 参与宿主细胞的病毒感染。
