scholarly journals A Molecular Study on Hepatitis E Virus (HEV) in Pigs in Bulgaria

2021 ◽  
Vol 8 (11) ◽  
pp. 267
Author(s):  
Andrea Palombieri ◽  
Ilia Tsachev ◽  
Vittorio Sarchese ◽  
Paola Fruci ◽  
Federica Di Profio ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Molecular Study ◽  
Open Reading Frame ◽  
Subtype C ◽  
Reading Frame ◽  
Rdrp Region ◽  
High Prevalence ◽  
Open Reading Frame 2 ◽  
Animal Reservoirs

Information on hepatitis E virus (HEV) strains circulating in animal reservoirs in Bulgaria is currently lacking. Herein, by screening HEV seropositive sera obtained from Bulgarian swine and wild boars, viral RNA was detected at high prevalence rate (28.2%) in industrial pigs. Sequence analysis of the partial polymerase (RdRp) region revealed the highest genetic correlation with HEVs of genotype (Gt) 3 identified in French and Dutch patients. For three such strains, a 700-bp fragment of the open reading frame 2 gene was generated. On phylogenetic analysis, the Bulgarian strains clustered tightly (93.8–98.3% nt) with human and animal HEVs classified within the Gt3 subtype c.

scholarly journals A Pilot Study on Hepatitis E Virus (HEV) Epidemiology in Animal Reservoirs in Bulgaria

2021 ◽  
Author(s):  
Andrea Palombieri ◽  
Ilia Tsachev ◽  
Vittorio Sarchese ◽  
Paola Fruci ◽  
Federica Di Profio ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Pilot Study ◽  
Sequence Analysis ◽  
Prevalence Rate ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Subtype C ◽  
Rdrp Region ◽  
High Prevalence ◽  
Animal Reservoirs

Abstract Information on hepatitis E virus (HEV) epidemiology in animal reservoirs in Bulgaria is still lacking. Herein, by screening HEV seropositive sera obtained from Bulgarian swine and wild boars, viral RNA was detected at high prevalence rate (28.2%) in industrial pigs. Sequence analysis of the partial polymerase (RdRp) region revealed the highest genetic correlation with HEVs of genotype (Gt) 3 identified in French and Dutch patients. For three such strains a 700-bp fragment of the ORF 2 gene was generated. On phylogenetic analysis, the Bulgarian strains clustered tightly (93.8-98.3% nt) with human and animal HEVs classified within the Gt3 subtype c.

scholarly journals Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1385
Author(s):  
Giulia Pezzoni ◽  
Lidia Stercoli ◽  
Eleonora Pegoiani ◽  
Emiliana Brocchi
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Recombinant Antigen ◽  
Open Reading Frame ◽  
Reading Frame ◽  
E Coli ◽  
Antigenic Characterization ◽  
Antigenic Properties ◽  
Open Reading Frame 2

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1–660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens’ immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394–608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394–608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461–544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

scholarly journals Hepatitis E Virus (HEV) Open Reading Frame 2 Antigen Kinetics in Human-Liver Chimeric Mice and Its Impact on HEV Diagnosis

2019 ◽  
Vol 220 (5) ◽  
pp. 811-819 ◽  
Author(s):  
Ibrahim M Sayed ◽  
Lieven Verhoye ◽  
Claire Montpellier ◽  
Florence Abravanel ◽  
Jacques Izopet ◽  
...  
Keyword(s):  
Density Gradient ◽  
Hepatitis E Virus ◽  
Gradient Analysis ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Viral Rna ◽  
Humanized Mice ◽  
Molecular Diagnostic ◽  
Reading Frame ◽  
Open Reading Frame 2

Abstract Background Hepatitis E virus infection (HEV) is an emerging problem in developed countries. Diagnosis of HEV infection is based on the detection of HEV-specific antibodies, viral RNA, and/or antigen (Ag). Humanized mice were previously reported as a model for the study of HEV infection, but published data were focused on the quantification of viral RNA. However, the kinetics of HEV Ag expression during infection remains poorly understood. Methods Plasma specimens and suspensions of fecal specimens from HEV-infected and ribavirin-treated humanized mice were analyzed using HEV antigen–specific enzyme-linked immunosorbent assay, reverse transcription–quantitative polymerase chain reaction analysis, density gradient analysis, and Western blotting. Result Open reading frame 2 (ORF2) Ag was detected in both plasma and stool from HEV-infected mice, and levels increased over time. Contrary to HEV RNA, ORF2 Ag levels were higher in mouse plasma than in stool. Interestingly, ORF2 was detected in plasma from mice that tested negative for HEV RNA in plasma but positive for HEV RNA in stool and was detected after viral clearance in mice that were treated with ribavirin. Plasma density gradient analysis revealed the presence of the noninfectious glycosylated form of ORF2. Conclusion ORF2 Ag can be used as a marker of active HEV infection and for assessment of the effect of antiviral therapy, especially when fecal samples are not available or molecular diagnostic tests are not accessible.

Primary structure of open reading frame 2 and 3 of the hepatitis E virus isolated from Morocco

1999 ◽  
Vol 57 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Jihong Meng ◽  
Mian-er Cong ◽  
Xing Dai ◽  
Jacques Pillot ◽  
Michael A. Purdy ◽  
...  
Keyword(s):  
Primary Structure ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Open Reading Frame 2

Molecular biology and pathogenesis of hepatitis E virus

1999 ◽  
Vol 1 (18) ◽  
pp. 1-16 ◽  
Author(s):  
Shahid Jameel
Keyword(s):  
Viral Genome ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Host Interactions ◽  
Processing Enzymes ◽  
Open Reading Frame 2

Hepatitis E virus (HEV) infection results in hepatitis E, an acute and self-limited disease. The virus is transmitted in a faecal–oral manner and is a major cause of viral hepatitis in much of the developing world, where it causes rampant sporadic infections and large epidemics. A curious feature of hepatitis E is the unusually high rates of mortality that are observed in pregnant women, in whom the disease is exacerbated by the development of fulminant liver disease. In the absence of viable in vitro propagation systems, several geographical isolates of HEV have been maintained in vivo in nonhuman primates and, subsequently, the viral genome has been cloned and sequenced. HEV has been classified provisionally into a separate family known as the HEV-like viruses, which has at least four recognised genotypes, but has only a single serotype. The viral genome is a positive-stranded (+)RNA of ~7.5 kb and encodes at least three proteins. Open reading frame 1 (ORF1) encodes the viral nonstructural polyprotein, which has domains that are homologous to some of the replication and processing enzymes found in other +RNA viruses. The HEV protein itself remains poorly characterised. The protein encoded by open reading frame 2 (ORF2) is the major HEV capsid protein, and the protein encoded by open reading frame 3 (ORF3) appears to be involved in virus–host interactions. Several questions related to the biology, epidemiology and pathogenesis of HEV remain unanswered; the progress of a few of these is reviewed here.

Expression and Immunoreactivities of Hepatitis E Virus Genotype 3 Open Reading Frame-2 (ORF-2) Recombinant Proteins Expressed in Insect Cells

2009 ◽  
Vol 1 (2) ◽  
pp. 77-84 ◽  
Author(s):  
Nereida Jiménez de Oya ◽  
Inmaculada Galindo ◽  
Estela Escribano-Romero ◽  
Ana-Belén Blázquez ◽  
Julio Alonso-Padilla ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Hepatitis E Virus ◽  
Insect Cells ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Genotype 3 ◽  
Virus Genotype ◽  
Reading Frame ◽  
Open Reading Frame 2

scholarly journals Vectorial Release of Hepatitis E Virus in Polarized Human Hepatocytes

2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Nicolas Capelli ◽  
Olivier Marion ◽  
Martine Dubois ◽  
Sophie Allart ◽  
Justine Bertrand-Michel ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Virus Protein ◽  
Reading Frame ◽  
Apical Side ◽  
Basolateral Side ◽  
Culture Supernatants ◽  
Open Reading Frame 2

ABSTRACT Hepatitis E virus (HEV) is a common cause of acute viral hepatitis worldwide. Most HEV infections are asymptomatic, but immunocompromised patients infected with HEV genotype 3 (HEV3), HEV4, or HEV7 may develop chronic infections. The HEV particles in stools are naked (nHEV), while those in the serum and culture supernatants (eHEV) are associated with lipids. Hepatocytes are polarized epithelial cells that have basolateral (oriented toward the blood) and apical (oriented toward the bile) exosomal pathways. We isolated a subclone, F2, from the human hepatocarcinoma cell line HepG2/C3A that grew as a polarized monolayer culture and had better HEV production than HepG2/C3A cells. F2 cells cultured on semipermeable collagen inserts and infected basolaterally with nHEV3 released 94.6% of virus particles apically, those infected with eHEV3 released 96.8% apically, and eHEV1-infected cells released 99.3% apically. Transcytosis was not involved. Density gradient centrifugation and NP-40 treatment showed that HEV particles released both apically and basolaterally were lipid associated. The apically released HEV3 and HEV1 particles were six and nine times more infectious than those released basolaterally, respectively. Confocal microscopy indicated that the open reading frame 2 (ORF2) capsid protein colocalized apically with ORF3 virus protein, the apical marker DPP4, and the recycling endosome GTPase Rab27a. The amounts of soluble glycosylated ORF2 secreted apically and basolaterally were similar. These polarized-hepatocyte data suggest that infectious HEV particles are mainly released into bile, while the small fraction released into blood could spread HEV throughout the host. IMPORTANCE Hepatitis E virus (HEV) in stools is naked, while that in culture supernatants and patients’ blood is lipid associated. Its life cycle in hepatocytes, polarized cells with a basolateral side communicating with blood and an apical side connected with bile, is incompletely understood. We have developed a polarized hepatocyte model and used the cells to analyze the supernatants bathing the apical and basolateral sides and HEV subcellular distribution. HEV particles from both sides were lipid associated, and most infectious HEV particles left the cell via its apical side. Similar amounts of the open reading frame 2 (ORF2) soluble capsid protein were secreted from both sides of the hepatocytes. This model mimicking physiological conditions should help clarify the HEV cell cycle in polarized hepatocytes.

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