Expression, characterization, and immunoreactivities of a soluble hepatitis E virus putative capsid protein species expressed in insect cells.

ABSTRACT 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 S-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 in vivo. 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. IMPORTANCE 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 in vitro, 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.

Download Full-text

Characterization of monoclonal antibodies to hepatitis E virus (HEV) capsid protein and identification of binding activity

Journal of Biomedical Science ◽

10.1007/s11373-007-9172-4 ◽

2007 ◽

Vol 14 (5) ◽

pp. 555-563 ◽

Cited By ~ 11

Author(s):

Junkun He ◽

Robert A. Kuschner ◽

Vincent Dewar ◽

Pierre Voet ◽

Ludmila V. Asher ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Capsid Protein ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Binding Activity

Download Full-text

Evidence of the Extrahepatic Replication of Hepatitis E Virus in Human Endometrial Stromal Cells

Pathogens ◽

10.3390/pathogens9040295 ◽

2020 ◽

Vol 9 (4) ◽

pp. 295 ◽

Cited By ~ 5

Author(s):

Mohamed A. El-Mokhtar ◽

Essam R. Othman ◽

Maha Y. Khashbah ◽

Ali Ismael ◽

Mohamed AA Ghaliony ◽

...

Keyword(s):

Capsid Protein ◽

Stromal Cells ◽

Hepatitis E Virus ◽

Inflammatory Responses ◽

Hepatitis E ◽

Endometrial Stromal Cells ◽

Extrahepatic Replication ◽

Efficient Replication ◽

Over Time

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. The tropism of HEV is not restricted to the liver, and the virus replicates in other organs. Not all the extrahepatic targets for HEV are identified. Herein, we found that non-decidualized primary human endometrial stromal cells (PHESCs), which are precursors for the decidua and placenta, are susceptible to HEV infection. PHESCs, isolated from healthy non-pregnant women (n = 5), were challenged with stool-derived HEV-1 and HEV-3. HEV RNA was measured by qPCR, and HEV capsid protein was assessed by flow cytometry, immunofluorescence (IF), and ELISA. HEV infection was successfully established in PHESCs. Intracellular and extracellular HEV RNA loads were increased over time, indicating efficient replication in vitro. In addition, HEV capsid protein was detected intracellularly in the HEV-infected PHESCs and accumulated extracellularly over time, confirming the viral assembly and release from the infected cells. HEV-1 replicated more efficiently in PHESCs than HEV-3 and induced more inflammatory responses. Ribavirin (RBV) treatment abolished the replication of HEV in PHESCs. In conclusion, PHESCs are permissive to HEV infection and these cells could be an endogenous source of HEV infection during pregnancy and mediate HEV vertical transmission.

Download Full-text