scholarly journals The putative capsid protein of the newly identified avian hepatitis E virus shares antigenic epitopes with that of swine and human hepatitis E viruses and chicken big liver and spleen disease virus

2002 ◽  
Vol 83 (9) ◽  
pp. 2201-2209 ◽  
Author(s):  
G. Haqshenas ◽  
F. F. Huang ◽  
M. Fenaux ◽  
D. K. Guenette ◽  
F. W. Pierson ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Disease Virus ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Cross Reactivity ◽  
Putative Open Reading Frame ◽  
Orf2 Protein ◽  
Avian Hepatitis E Virus ◽  
Avian Hev ◽  
Antigenic Epitopes

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.

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 ◽  
...  
Keyword(s):  
Viral Infection ◽  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Organic Anion ◽  
Hepatitis E ◽  
Host Cells ◽  
Cell Culture System ◽  
Organic Anion Transporting Polypeptide ◽  
Avian Hepatitis E Virus ◽  
Avian Hev

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.

scholarly journals Characterization of Two Novel Linear B-Cell Epitopes in the Capsid Protein of Avian Hepatitis E Virus (HEV) That Are Common to Avian, Swine, and Human HEVs

2015 ◽  
Vol 89 (10) ◽  
pp. 5491-5501 ◽  
Author(s):  
Xinjie Wang ◽  
Qin Zhao ◽  
Lu Dang ◽  
Yani Sun ◽  
Jiming Gao ◽  
...  
Keyword(s):  
Amino Acid ◽  
B Cell ◽  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Antigenic Structure ◽  
B Cell Epitopes ◽  
Avian Hepatitis E Virus ◽  
Avian Hev ◽  
Linear B

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.

scholarly journals Identification of B-cell epitopes in the capsid protein of avian hepatitis E virus (avian HEV) that are common to human and swine HEVs or unique to avian HEV

2006 ◽  
Vol 87 (1) ◽  
pp. 217-223 ◽  
Author(s):  
H. Guo ◽  
E.-M. Zhou ◽  
Z. F. Sun ◽  
X.-J. Meng ◽  
P. G. Halbur
Keyword(s):  
B Cell ◽  
Hepatitis E Virus ◽  
Genomic Sequence ◽  
Rabbit Antiserum ◽  
Hepatitis E ◽  
Sequence Difference ◽  
B Cell Epitopes ◽  
Orf2 Protein ◽  
Avian Hepatitis E Virus ◽  
Avian Hev

Avian hepatitis E virus (avian HEV) was recently discovered in chickens from the USA that had hepatitis–splenomegaly (HS) syndrome. The complete genomic sequence of avian HEV shares about 50 % nucleotide sequence identity with those of human and swine HEVs. The open reading frame 2 (ORF2) protein of avian HEV has been shown to cross-react with human and swine HEV ORF2 proteins, but the B-cell epitopes in the avian HEV ORF2 protein have not been identified. Nine synthetic peptides from the predicted four antigenic domains of the avian HEV ORF2 protein were synthesized and corresponding rabbit anti-peptide antisera were generated. Using recombinant ORF2 proteins, convalescent pig and chicken antisera, peptides and anti-peptide rabbit sera, at least one epitope at the C terminus of domain II (possibly between aa 477–492) that is unique to avian HEV, one epitope in domain I (aa 389–410) that is common to avian, human and swine HEVs, and one or more epitopes in domain IV (aa 583–600) that are shared between avian and human HEVs were identified. Despite the sequence difference in ORF2 proteins between avian and mammalian HEVs and similar ORF2 sequence between human and swine HEV ORF2 proteins, rabbit antiserum against peptide 6 (aa 389–399) recognized only human HEV ORF2 protein, suggesting complexity of the ORF2 antigenicity. The identification of these B-cell epitopes in avian HEV ORF2 protein may be useful for vaccine design and may lead to future development of immunoassays for differential diagnosis of avian, swine and human HEV infections.

scholarly journals Identification of an antigenic domain in the N-terminal region of avian hepatitis E virus (HEV) capsid protein that is not common to swine and human HEVs

2014 ◽  
Vol 95 (12) ◽  
pp. 2710-2715 ◽  
Author(s):  
Lizhen Wang ◽  
Yani Sun ◽  
Taofeng Du ◽  
Chengbao Wang ◽  
Shuqi Xiao ◽  
...  
Keyword(s):  
Amino Acid ◽  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Amino Acid Residues ◽  
Antigenic Domains ◽  
Avian Hepatitis E Virus ◽  
Avian Hev ◽  
Selection Of ◽  
Antigenic Domain

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.

scholarly journals Identification of two neutralization epitopes on the capsid protein of avian hepatitis E virus

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

scholarly journals The fate of Hepatitis E virus capsid protein is regulated by an Arginine-Rich Motif

2021 ◽  
Author(s):  
Kévin Hervouet ◽  
Martin Ferrié ◽  
Maliki Ankavay ◽  
Claire Montpellier ◽  
Charline Camuzet ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Nuclear Translocation ◽  
Hepatitis E ◽  
Particle Assembly ◽  
Humoral Immune ◽  
Antiviral Responses ◽  
Orf2 Protein ◽  
Molecular Determinants ◽  
Arginine Rich Motif

Producing multifunctional proteins is one of the major strategies developed by viruses to condense their genetic information. Here, we investigated the molecular determinants of the multifunctionality of hepatitis E virus (HEV) ORF2 capsid protein. We previously identified 3 isoforms of ORF2 which are partitioned in different subcellular compartments to perform distinct functions. Notably, the infectious ORF2 (ORF2i) protein is the structural component of the virion, whereas the genome-free secreted and glycosylated ORF2 proteins likely act as a humoral immune decoy. We identified a 5 amino acid Arginine-Rich Motif (ARM) located in the ORF2 N-terminal region as a central regulator of the subcellular localizations and functions of ORF2 isoforms. We showed that the ARM controls ORF2 nuclear translocation, promoting regulation of host antiviral responses. This motif also regulates the dual topology and functionality of ORF2 signal peptide, leading to the production of either cytosolic infectious ORF2i or reticular non-infectious glycosylated ORF2 forms. Furthermore, the ARM likely serves as a cleavage site of the glycosylated ORF2 protein. Finally, it promotes ORF2 membrane association that is likely essential for particle assembly. In conclusion, our observations highlight ORF2 ARM as a unique central regulator of ORF2 addressing that finely controls the HEV lifecycle.

scholarly journals Analysis of the complete genomic sequence of an apparently avirulent strain of avian hepatitis E virus (avian HEV) identified major genetic differences compared with the prototype pathogenic strain of avian HEV

2007 ◽  
Vol 88 (5) ◽  
pp. 1538-1544 ◽  
Author(s):  
P. Billam ◽  
Z. F. Sun ◽  
X.-J. Meng
Keyword(s):  
Nucleotide Sequence Identity ◽  
Hepatitis E Virus ◽  
Genomic Sequence ◽  
Hepatitis E ◽  
Prototype Strain ◽  
Avirulent Strain ◽  
Sequence Identity ◽  
Avian Hepatitis E Virus ◽  
Avian Hev ◽  
Complete Genomic

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.

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