scholarly journals Chicken Organic Anion-Transporting Polypeptide 1A2, a Novel Avian Hepatitis E Virus (HEV) ORF2-Interacting Protein, Is Involved in Avian HEV Infection

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Huixia Li ◽  
Mengnan Fan ◽  
Baoyuan Liu ◽  
Pinpin Ji ◽  
Yiyang Chen ◽  
...  

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.

2021 ◽  
Vol 12 ◽  
Author(s):  
Mengnan Fan ◽  
Yuhang Luo ◽  
Beibei Zhang ◽  
Jiaxi Wang ◽  
Tianxiang Chen ◽  
...  

Hepatitis E Virus (HEV) causes viral hepatitis in humans worldwide, while a subset of HEV species, avian HEV, causes hepatitis-splenomegaly syndrome in chickens. To date, there are few reports on the host proteins interacting with HEV and being involved in viral infection. Previous pull-down assay combining mass spectrometry indicated that cell division control protein 42 (CDC42), a member belonging to the Rho GTPase family, was pulled down by avian HEV capsid protein. We confirmed the direct interaction between CDC42 and avian and mammalian HEV capsid proteins. The interaction can increase the amount of active guanosine triphosphate binding CDC42 state (GTP-CDC42). Subsequently, we determined that the expression and activity of CDC42 were positively correlated with HEV infection in the host cells. Using the different inhibitors of CDC42 downstream signaling pathways, we found that CDC42-MRCK (a CDC42-binding kinase)-non-myosin IIA (NMIIA) pathway is involved in naked avian and mammalian HEV infection, CDC42-associated p21-activated kinase 1 (PAK1)-NMIIA/Cofilin pathway is involved in quasi-enveloped mammalian HEV infection and CDC42-neural Wiskott-Aldrich syndrome protein-actin-polymerizing protein Arp2/3 pathway (CDC42-(N-)WASP-Arp2/3) pathway participates in naked and quasi-enveloped mammalian HEV infection. Collectively, these results demonstrated for the first time that HEV capsid protein can directly bind to CDC42, and non- and quasi-enveloped HEV use different CDC42 downstream signaling pathways to participate in viral infection. The study provided some new insights to understand the life cycle of HEV in host cells and a new target of drug design for combating HEV infection.


2015 ◽  
Vol 89 (10) ◽  
pp. 5491-5501 ◽  
Author(s):  
Xinjie Wang ◽  
Qin Zhao ◽  
Lu Dang ◽  
Yani Sun ◽  
Jiming Gao ◽  
...  

ABSTRACTAntisera raised against the avian hepatitis E virus (HEV) capsid protein are cross-reactive with human and swine HEV capsid proteins. In this study, two monoclonal antibodies (MAbs) against the avian HEV capsid protein, namely, 3E8 and 1B5, were shown to cross-react with the swine HEV capsid protein. The motifs involved in binding both MAbs were identified and characterized using phage display biopanning, peptide synthesis, and truncated or mutated protein expression, along with indirect enzyme-linked immunosorbent assay (ELISA) and Western blotting. The results showed that the I/VPHD motif is a necessary core sequence and that P and H are two key amino acids for recognition by MAb 3E8. The VKLYM/TS motif is the minimal amino acid sequence necessary for recognition by MAb 1B5. Cross-reactivity between the two epitopes and antibodies against avian, swine, and human HEVs in sera showed that both epitopes are common to avian, swine, and human HEVs. In addition, amino acid sequence alignment of the capsid proteins revealed that the key motifs of both novel epitopes are the same in HEVs from different animal species, predicting that they may be common to HEV isolates from boars, rabbits, rats, ferrets, mongooses, deer, and camels as well. Protein modeling analysis showed that both epitopes are at least partially exposed on the surface of the HEV capsid protein. Protective capacity analysis demonstrated that the two epitopes are nonprotective against avian HEV infection in chickens. Collectively, these studies characterize two novel linear B-cell epitopes common to avian, swine, and human HEVs, which furthers the understanding of HEV capsid protein antigenic structure.IMPORTANCEMore and more evidence indicates that the host range diversity of hepatitis E virus (HEV) is a global public health concern. A better understanding of the antigenic structure of the HEV capsid protein may improve disease diagnosis and prevention. In this study, binding site mapping and localization as well as the antigenic biology of two novel linear B-cell epitopes common to several different species of HEV were characterized. These findings partially reveal the antigenic structure of the HEV capsid protein and provide potential applications for the development of diagnostics and interventions for HEV infection.


2002 ◽  
Vol 83 (9) ◽  
pp. 2201-2209 ◽  
Author(s):  
G. Haqshenas ◽  
F. F. Huang ◽  
M. Fenaux ◽  
D. K. Guenette ◽  
F. W. Pierson ◽  
...  

We recently identified a novel virus, designated avian hepatitis E virus (avian HEV), from chickens with hepatitis–splenomegaly (HS) syndrome in the USA. We showed that avian HEV is genetically related to swine and human HEVs. Here we report the antigenic cross-reactivity of the putative open reading frame 2 (ORF2) capsid protein of avian HEV with those of swine and human HEVs and the Australian chicken big liver and spleen disease virus (BLSV). The region encoding the C-terminal 268 amino acid residues of avian HEV ORF2 was cloned into expression vector pRSET-C. The truncated ORF2 protein was expressed in E. coli as a fusion protein and purified by affinity chromatography. Western blot analysis revealed that the avian HEV ORF2 protein reacted with antisera against the Sar-55 strain of human HEV and with convalescent antisera against swine HEV and the US2 strain of human HEV, as well as with antiserum against BLSV. Convalescent sera from specific-pathogen-free chickens experimentally infected with avian HEV also reacted with the recombinant capsid proteins of swine HEV and Sar-55 human HEV. Antisera against the US2 human HEV also reacted with recombinant ORF2 proteins of both swine HEV and Sar-55 human HEV. The antigenic cross-reactivity of the avian HEV putative capsid protein with those of swine and human HEVs was further confirmed, for the most part, by ELISA assays. The data indicate that avian HEV shares certain antigenic epitopes in its putative capsid protein with swine and human HEVs, as well as with BLSV. The results have implications for HEV diagnosis and taxonomy.


2014 ◽  
Vol 95 (12) ◽  
pp. 2710-2715 ◽  
Author(s):  
Lizhen Wang ◽  
Yani Sun ◽  
Taofeng Du ◽  
Chengbao Wang ◽  
Shuqi Xiao ◽  
...  

The antigenic domains located in the C-terminal 268 amino acid residues of avian hepatitis E virus (HEV) capsid protein have been characterized. This region shares common epitopes with swine and human HEVs. However, epitopes in the N-terminal 338 amino acid residues have never been reported. In this study, an antigenic domain located between amino acids 23 and 85 was identified by indirect ELISA using the truncated recombinant capsid proteins as coating antigens and anti-avian HEV chicken sera as primary antibodies. In addition, this domain did not react with anti-swine and human HEV sera. These results indicated that the N-terminal 338 amino acid residues of avian HEV capsid protein do not share common epitopes with swine and human HEVs. This finding is important for our understanding of the antigenicity of the avian HEV capsid protein. Furthermore, it has important implications in the selection of viral antigens for serological diagnosis.


2008 ◽  
Vol 89 (2) ◽  
pp. 500-508 ◽  
Author(s):  
E.-M. Zhou ◽  
H. Guo ◽  
F. F. Huang ◽  
Z. F. Sun ◽  
X. J. Meng

2007 ◽  
Vol 88 (5) ◽  
pp. 1538-1544 ◽  
Author(s):  
P. Billam ◽  
Z. F. Sun ◽  
X.-J. Meng

Avian hepatitis E virus (HEV) was identified from chickens with hepatitis–splenomegaly syndrome. In this study, the complete genomic sequence of an apparently avirulent strain of avian HEV was determined to be 6649 nt in length, excluding the poly(A) tail, which is 5 nt shorter than the prototype avian HEV. Sequence analyses revealed that the ORF1 has 89.6 % nucleotide sequence identity, with numerous non-silent mutations and deletions, compared to the prototype strain. The ORF2 capsid gene showed 90.7 % sequence identity with six non-silent mutations, and ORF3 had four non-silent mutations with 97 % sequence identity. Overall, the apparently avirulent strain shares only 90.1 % nucleotide sequence identity with the prototype strain. The identification of significant non-silent mutations in the capsid gene and other regions suggests that these mutations may play a role in HEV attenuation. This is the first report of the full-length sequence of an apparently avirulent strain of HEV.


2008 ◽  
Vol 153 (4) ◽  
pp. 657-666 ◽  
Author(s):  
Masaharu Takahashi ◽  
Yu Hoshino ◽  
Toshinori Tanaka ◽  
Hideyuki Takahashi ◽  
Tsutomu Nishizawa ◽  
...  

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