Mapping of linear B cell epitopes on open reading frames 2- and 3-encoded proteins of hepatitis E virus using synthetic peptides

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.

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An analysis of two open reading frames (ORF3 and ORF4) of rat hepatitis E virus genome using its infectious cDNA clones with mutations in ORF3 or ORF4

Virus Research ◽

10.1016/j.virusres.2018.02.014 ◽

2018 ◽

Vol 249 ◽

pp. 16-30 ◽

Cited By ~ 6

Author(s):

Tanggis ◽

Tominari Kobayashi ◽

Masaharu Takahashi ◽

Suljid Jirintai ◽

Tsutomu Nishizawa ◽

...

Keyword(s):

Hepatitis E Virus ◽

Hepatitis E ◽

Virus Genome ◽

Open Reading Frames ◽

Cdna Clones ◽

Reading Frames

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The effects of synonymous codon usages on genotypic formation of open reading frames in hepatitis E virus

Infection Genetics and Evolution ◽

10.1016/j.meegid.2020.104450 ◽

2020 ◽

Vol 85 ◽

pp. 104450

Author(s):

Jing Sun ◽

Caiqin Ren ◽

Ying Huang ◽

Wenhan Chao ◽

Fuqiang Xie

Keyword(s):

Hepatitis E Virus ◽

Synonymous Codon ◽

Hepatitis E ◽

Open Reading Frames ◽

Reading Frames

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Immunogenecity of synthetic peptides representing linear B-cell epitopes of VapA of Rhodococcus equi

Vaccine ◽

10.1016/j.vaccine.2003.10.006 ◽

2004 ◽

Vol 22 (9-10) ◽

pp. 1114-1123 ◽

Cited By ~ 18

Author(s):

Saı̈d Taouji ◽

Izumi Nomura ◽

Steeve Giguère ◽

Seiji Tomomitsu ◽

Tsutomu Kakuda ◽

...

Keyword(s):

B Cell ◽

Synthetic Peptides ◽

Rhodococcus Equi ◽

B Cell Epitopes ◽

Linear B

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Linear B-cell epitopes of the NS3-NS4-NS5 proteins of the hepatitis C virusas modeled with synthetic peptides

Virology ◽

10.1016/s0042-6822(95)80086-7 ◽

1995 ◽

Vol 206 (1) ◽

pp. 666-672 ◽

Cited By ~ 36

Author(s):

Yu.E. Khudyakov ◽

N.S. Khudyakova ◽

D.L. Jue ◽

S.B. Lambert ◽

S. Fang ◽

...

Keyword(s):

Hepatitis C ◽

B Cell ◽

Synthetic Peptides ◽

B Cell Epitopes ◽

Linear B

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Genotype-Specific Evolution of Hepatitis E Virus

Journal of Virology ◽

10.1128/jvi.02241-16 ◽

2017 ◽

Vol 91 (9) ◽

Cited By ~ 18

Author(s):

Adam B. Brayne ◽

Bethany L. Dearlove ◽

James S. Lester ◽

Sergei L. Kosakovsky Pond ◽

Simon D. W. Frost

Keyword(s):

Positive Selection ◽

Hepatitis E Virus ◽

Hepatitis E ◽

Open Reading Frames ◽

Genotype 1 ◽

Natural Case ◽

Evolutionary Changes ◽

Single Host ◽

Multiple Species ◽

Reading Frames

ABSTRACT Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis globally. HEV comprises four genotypes with different geographic distributions and host ranges. We utilize this natural case-control study for investigating the evolution of zoonotic viruses compared to single-host viruses, using 244 near-full-length HEV genomes. Genome-wide estimates of the ratio of nonsynonymous to synonymous evolutionary changes (dN/dS ratio) located a region of overlapping reading frames, which is subject to positive selection in genotypes 3 and 4. The open reading frames (ORFs) involved have functions related to host-pathogen interaction, so genotype-specific evolution of these regions may reflect their fitness. Bayesian inference of evolutionary rates shows that genotypes 3 and 4 have significantly higher rates than genotype 1 across all ORFs. Reconstruction of the phylogenies of zoonotic genotypes demonstrates significant intermingling of isolates between hosts. We speculate that the genotype-specific differences may result from cyclical adaptation to different hosts in genotypes 3 and 4. IMPORTANCE Hepatitis E virus (HEV) is increasingly recognized as a pathogen that affects both the developing and the developed world. While most often clinically mild, HEV can be severe or fatal in certain demographics, such as expectant mothers. Like many other viral pathogens, HEV has been classified into several distinct genotypes. We show that most of the HEV genome is evolutionarily constrained. One locus of positive selection is unusual in that it encodes two distinct protein products. We are the first to detect positive selection in this overlap region. Genotype 1, which infects humans only, appears to be evolving differently from genotypes 3 and 4, which infect multiple species, possibly because genotypes 3 and 4 are unable to achieve the same fitness due to repeated host jumps.

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Comparison of two different methods using overlapping synthetic peptides for localizing linear B cell epitopes in the U1 snRNP-C autoantigen

Journal of Immunological Methods ◽

10.1016/s0022-1759(96)00171-8 ◽

1996 ◽

Vol 199 (1) ◽

pp. 77-85 ◽

Cited By ~ 18

Author(s):

Hubert Halimi ◽

Hélène Dumortier ◽

Jean-Paul Briand ◽

Sylviane Muller

Keyword(s):

B Cell ◽

Synthetic Peptides ◽

B Cell Epitopes ◽

U1 Snrnp ◽

Linear B

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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

Journal of General Virology ◽

10.1099/vir.0.81393-0 ◽

2006 ◽

Vol 87 (1) ◽

pp. 217-223 ◽

Cited By ~ 48

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.

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Progress in the Production of Virus-Like Particles for Vaccination against Hepatitis E Virus

Viruses ◽

10.3390/v12080826 ◽

2020 ◽

Vol 12 (8) ◽

pp. 826

Author(s):

Milena Mazalovska ◽

J. Calvin Kouokam

Keyword(s):

Viral Hepatitis ◽

Hepatitis E Virus ◽

Vaccine Development ◽

Genetic Material ◽

Hepatitis E ◽

Open Reading Frames ◽

Virus Like Particles ◽

Ssrna Virus ◽

Potential Vaccine ◽

Reading Frames

Hepatitis E virus (HEV), a pathogen that causes acute viral hepatitis, is a small icosahedral, quasi-enveloped, positive ssRNA virus. Its genome has three open reading frames (ORFs), with ORF1 and ORF3 encoding for nonstructural and regulatory proteins, respectively, while ORF2 is translated into the structural, capsid protein. ORF2 is most widely used for vaccine development in viral hepatitis. Hepatitis E virus-like particles (VLPs) are potential vaccine candidates against HEV infection. VLPs are composed of capsid subunits mimicking the natural configuration of the native virus but lack the genetic material needed for replication. As a result, VLPs are unable to replicate and cause disease, constituting safe vaccine platforms. Currently, the recombinant VLP-based vaccine Hecolin® against HEV is only licensed in China. Herein, systematic information about the expression of various HEV ORF2 sequences and their ability to form VLPs in different systems is provided.

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