scholarly journals The ATP synthase subunit β (ATP5B) is an entry factor for the hepatitis E virus

2016 ◽  
Author(s):  
Zulfazal Ahmed ◽  
Prasida Holla ◽  
Imran Ahmad ◽  
Shahid Jameel
Keyword(s):  
Atp Synthase ◽  
Hepatitis E Virus ◽  
Viral Infections ◽  
Rna Virus ◽  
High Titer ◽  
Mitochondrial Protein ◽  
Hepatitis E ◽  
E Coli ◽  
Mass Spectrometric Approach

AbstractHepatitis E occurs sporadically and as outbreaks due to contamination of drinking water. The causative agent, hepatitis E virus (HEV) is a hepatotropic non-enveloped RNA virus, which grows poorlyin vitro.Consequently, many aspects of HEV biology are poorly characterized, including its cellular receptor and entry mechanism(s). Previous studies from our laboratory have shown that heparan sulfate proteoglycans (HSPGs) act as attachment factors for the virus. In the absence of purified high titer infectious virus, we have used hepatitis E virus-like particles (HEV-LPs) expressed and purified fromE. colito identify HEV entry factor(s) on liver cells in culture. Using a pull down and mass spectrometric approach, we identified the ATP synthase subunit β (ATP5B) to bind the HEV capsid protein. Its role in the entry of HEV was then validated using antibody and siRNA mediated approaches, and infectious HEV from the stools of a hepatitis E patient. Though ATP synthase is largely a mitochondrial protein, the cell surface expressed form of ATP5B is implicated in other viral infections.

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.

1354 IN VITRO INFECTION AND REPLICATION OF HEPATITIS E VIRUS IN HUMAN HEPATOCYTES

2011 ◽  
Vol 54 ◽  
pp. S535
Author(s):  
Y. Oshiro ◽  
H. Yasue ◽  
S. Hattori ◽  
M. Chiba ◽  
T. Naito ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Human Hepatocytes

scholarly journals Hepatitis E Virus Immunopathogenesis

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1180
Author(s):  
Kush Kumar Yadav ◽  
Scott P. Kenney
Keyword(s):  
Hepatitis E Virus ◽  
Organ Transplant ◽  
Hepatitis E ◽  
Oral Route ◽  
Solid Organ ◽  
Immunocompromised Patients ◽  
In Vivo Models ◽  
Transplant Patients

Hepatitis E virus is an important emerging pathogen producing a lethal impact on the pregnant population and immunocompromised patients. Starting in 1983, it has been described as the cause for acute hepatitis transmitted via the fecal–oral route. However, zoonotic and blood transfusion transmission of HEV have been reported in the past few decades, leading to the detailed research of HEV pathogenesis. The reason behind HEV being highly virulent to the pregnant population particularly during the third trimester, leading to maternal and fetal death, remains unknown. Various host factors (immunological, nutritional, hormonal) and viral factors have been studied to define the key determinants assisting HEV to be virulent in pregnant and immunocompromised patients. Similarly, chronic hepatitis is seen particularly in solid organ transplant patients, resulting in fatal conditions. This review describes recent advances in the immunopathophysiology of HEV infections in general, pregnant, and immunocompromised populations, and further elucidates the in vitro and in vivo models utilized to understand HEV pathogenesis.

scholarly journals Optimized Hepatitis E Virus (HEV) Culture and Its Application to Measurements of HEV Infectivity

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 139 ◽  
Author(s):  
Nicolas Capelli ◽  
Martine Dubois ◽  
Mélanie Pucelle ◽  
Isabelle Da Silva ◽  
Sébastien Lhomme ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Fetal Bovine Serum ◽  
Hepatitis E ◽  
Chronic Liver Diseases ◽  
Infectious Dose ◽  
Clinical Strains ◽  
Fetal Bovine ◽  
Culture Supernatants ◽  
Tissue Culture Infectious Dose

Hepatitis E virus (HEV) is a major concern in public health worldwide. Infections with HEV genotypes 3, 4, or 7 can lead to chronic hepatitis while genotype 1 infections can trigger severe hepatitis in pregnant women. Infections with all genotypes can worsen chronic liver diseases. As virions are lipid-associated in blood and naked in feces, efficient methods of propagating HEV clinical strains in vitro and evaluating the infectivity of both HEV forms are needed. We evaluated the spread of clinical strains of HEV genotypes 1 (HEV1) and 3 (HEV3) by quantifying viral RNA in culture supernatants and cell lysates. Infectivity was determined by endpoint dilution and calculation of the tissue culture infectious dose 50 (TCID50). An enhanced HEV production could be obtained varying the composition of the medium, including fetal bovine serum (FBS) and dimethylsulfoxide (DMSO) content. This increased TCID50 from 10 to 100-fold and allowed us to quantify HEV1 infectivity. These optimized methods for propagating and measuring HEV infectivity could be applied to health safety processes and will be useful for testing new antiviral drugs.

Hepatitis E virus

2011 ◽  
Author(s):  
X. J. Meng
Keyword(s):  
Hepatitis E Virus ◽  
Animal Species ◽  
Rna Virus ◽  
Hepatitis E ◽  
Open Reading Frames ◽  
Industrialized Countries ◽  
Efficient Cell Culture System ◽  
The Family ◽  
Avian Hev ◽  
Animal Strains

Hepatitis E virus (HEV) is a small, non-enveloped, single-strand, positive-sense RNA virus of approximately 7.2 kb in size. HEV is classified in the family Hepeviridae consisting of four recognized major genotypes that infect humans and other animals. Genotypes 1 and 2 HEV are restricted to humans and often associated with large outbreaks and epidemics in developing countries with poor sanitation conditions, whereas genotypes 3 and 4 HEV infect humans, pigs and other animal species and are responsible for sporadic cases of hepatitis E in both developing and industrialized countries. The avian HEV associated with Hepatitis-Splenomegaly syndrome in chickens is genetically and antigenically related to mammalian HEV, and likely represents a new genus in the family. There exist three open reading frames in HEV genome: ORF1 encodes non-structural proteins, ORF2 encodes the capsid protein, and the ORF3 encodes a small phosphoprotein. ORF2 and ORF3 are translated from a single bicistronic mRNA, and overlap each other but neither overlaps ORF1. Due to the lack of an efficient cell culture system and a practical animal model for HEV, the mechanisms of HEV replication and pathogenesis are poorly understood. The recent identification and characterization of animal strains of HEV from pigs and chickens and the demonstrated ability of cross-species infection by these animal strains raise potential public health concerns for zoonotic HEV transmission. It has been shown that the genotypes 3 and 4 HEV strains from pigs can infect humans, and vice versa. Accumulating evidence indicated that hepatitis E is a zoonotic disease, and swine and perhaps other animal species are reservoirs for HEV. A vaccine against HEV is not yet available.

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

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 295 ◽  
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.

scholarly journals Construction and characterization of infectious cDNA clones of a chicken strain of hepatitis E virus (HEV), avian HEV

2005 ◽  
Vol 86 (9) ◽  
pp. 2585-2593 ◽  
Author(s):  
F. F. Huang ◽  
F. W. Pierson ◽  
T. E. Toth ◽  
X. J. Meng
Keyword(s):  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Cdna Clones ◽  
Virus Shedding ◽  
Rna Transcripts ◽  
Successful Infection ◽  
The Usa ◽  
Avian Hev

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important human pathogen. Increasing evidence indicates that hepatitis E is a zoonosis. Avian HEV was recently discovered in chickens with hepatitis–splenomegaly syndrome in the USA. Like swine HEV from pigs, avian HEV is also genetically and antigenically related to human HEV. The objective of this study was to construct and characterize an infectious cDNA clone of avian HEV for future studies of HEV replication and pathogenesis. Three full-length cDNA clones of avian HEV, pT7-aHEV-5, pT7G-aHEV-10 and pT7G-aHEV-6, were constructed and their infectivity was tested by in vitro transfection of leghorn male hepatoma (LMH) chicken liver cells and by direct intrahepatic inoculation of specific-pathogen-free (SPF) chickens with capped RNA transcripts from the three clones. The results showed that the capped RNA transcripts from each of the three clones were replication competent when transfected into LMH cells as demonstrated by detection of viral antigens with avian HEV-specific antibodies. SPF chickens intrahepatically inoculated with the capped RNA transcripts from each of the three clones developed active avian HEV infections as evidenced by seroconversion to avian HEV antibodies, viraemia and faecal virus shedding. The infectivity was further confirmed by successful infection of naïve chickens with the viruses recovered from chickens inoculated with the RNA transcripts. The results indicated that all three cDNA clones of avian HEV are infectious both in vitro and in vivo. The availability of these infectious clones for a chicken strain of HEV now affords an opportunity to study the mechanisms of HEV cross-species infection and tissue tropism by constructing chimeric viruses among human, swine and avian HEVs.

scholarly journals Ribavirin InhibitsIn VitroHepatitis E Virus Replication through Depletion of Cellular GTP Pools and Is Moderately Synergistic with Alpha Interferon

2013 ◽  
Vol 58 (1) ◽  
pp. 267-273 ◽  
Author(s):  
Yannick Debing ◽  
Suzanne U. Emerson ◽  
Yijin Wang ◽  
Qiuwei Pan ◽  
Jan Balzarini ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Hepatitis E Virus ◽  
Clinical Effectiveness ◽  
Hepatitis E ◽  
Alpha Interferon ◽  
Chronic Infections ◽  
Genotype 3 ◽  
Subgenomic Replicon ◽  
First Time

ABSTRACTHepatitis E virus (HEV) is a common cause of acute hepatitis that results in high mortality in pregnant women and may establish chronic infections in immunocompromised patients. We demonstrate for the first time that alpha interferon (IFN-α) and ribavirin inhibitin vitroHEV replication in both a subgenomic replicon and an infectious culture system based on a genotype 3 strain. IFN-α showed a moderate but significant synergism with ribavirin. These findings corroborate the reported clinical effectiveness of both drugs. In addition, the antiviral activity of ribavirin against wild-type genotype 1, 2, and 3 strains was confirmed by immunofluorescence staining. Furthermore, thein vitroactivity of ribavirin depends on depletion of intracellular GTP pools, which is evident from the facts that (i) other GTP-depleting agents (5-ethynyl-1-β-d-ribofuranosylimidazole-4-carboxamide [EICAR] and mycophenolic acid) inhibit viral replication, (ii) exogenously added guanosine reverses the antiviral effects, and (iii) a strong correlation (R2= 0.9998) exists between the antiviral activity and GTP depletion of ribavirin and other GTP-depleting agents.

scholarly journals Cytoplasmic Localization of the ORF2 Protein of Hepatitis E Virus Is Dependent on Its Ability To Undergo Retrotranslocation from the Endoplasmic Reticulum

2007 ◽  
Vol 81 (7) ◽  
pp. 3339-3345 ◽  
Author(s):  
Milan Surjit ◽  
Shahid Jameel ◽  
Sunil K. Lal
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis E Virus ◽  
Major Capsid Protein ◽  
Rna Virus ◽  
Hepatitis E ◽  
26S Proteasome ◽  
Orf2 Protein ◽  
Surface Localization ◽  
Positive Strand Rna Virus ◽  
Positive Strand Rna

ABSTRACT Hepatitis E virus (HEV) is a positive-strand RNA virus that is prevalent in much of the developing world. ORF2 is the major capsid protein of HEV. Although ORF2 is an N-linked glycoprotein, it is abundantly located in the cytoplasm in addition to having membrane and surface localization. The mechanism by which ORF2 protein obtains access to the cytoplasm is unknown. In this report, we prove that initially all ORF2 protein is present in the endoplasmic reticulum and a fraction of it becomes retrotranslocated to the cytoplasm. The ability of ORF2 to be retrotranslocated is dependent on its glycosylation status and follows the canonical dislocation pathway. However, in contrast to general substrates of the dislocation pathway, retrotranslocated ORF2 protein is not a substrate of the 26S proteasome complex and is readily detectable in the cytoplasm in the absence of any protease inhibitor, suggesting that the retrotranslocated protein is stable in the cytoplasm. This study thus defines the pathway by which ORF2 obtains access to the cytoplasm.

scholarly journals Activation of CXCL-8 Transcription by Hepatitis E Virus ORF-1 via AP-1

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zhubing Li ◽  
Lu Chen ◽  
Qiang Liu
Keyword(s):  
Transcriptional Activation ◽  
Promoter Activity ◽  
Hepatitis E Virus ◽  
Rna Virus ◽  
Ectopic Expression ◽  
Hepatitis E ◽  
Genomic Rna ◽  
Host Interactions ◽  
Positive Sense ◽  
Binding Sequence

Hepatitis E virus (HEV) is a small nonenveloped single-stranded positive-sense RNA virus and is one of the major causes for acute hepatitis worldwide. CXCL-8 is a small multifunctional proinflammatory chemokine. It was reported recently that HEV infection significantly upregulates CXCL-8 gene expression. In this study, we investigated the mechanism of HEV-induced CXCL-8 transcriptional activation. Using CXCL-8 promoter reporters of different lengths ranging from −1400 to −173, we showed that −173 promoter has the highest promoter activity in the presence of HEV genomic RNA, indicating that the −173 promoter contains sequences responsible for CXCL-8 activation by HEV. Ectopic expression of the ORF-1 protein can upregulate the −173 CXCL-8 promoter activity. In contrast, expression of the ORF-2 protein suppresses the CXCL-8 promoter activity and expression of the ORF-3 protein has no effect on the CXCL-8 promoter activity. We further showed that AP-1 is required for CXCL-8 activation because neither HEV genomic RNA nor the ORF-1 protein can upregulate the −173 CXCL-8 promoter in the absence of the AP-1 binding sequence. Taken together, our results showed that HEV and HEV ORF-1 protein activate the CXCL-8 promoter via AP-1. This novel function of HEV ORF-1 protein should contribute to our understanding of HEV-host interactions and HEV-associated pathogenesis.

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