Deletions of the Hypervariable Region (HVR) in Open Reading Frame 1 of Hepatitis E Virus Do Not Abolish Virus Infectivity: Evidence for Attenuation of HVR Deletion Mutants In Vivo

Pudupakam, Raghavendra Sumanth; Huang, Yao; Opriessnig, Tanja; Halbur, Pat; Pierson, F. W.; Meng, Xiang‐Jin

doi:10.1128/jvi.01854-08

Cited by 88 publications

(103 citation statements)

References 59 publications

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“…Therefore, insertions within the HVR would not be expected to disrupt any function. The HVR has not been characterized extensively, but one comparison (21) suggests that, within each genotype, certain sequence patterns may be conserved; the HVR sequences of genotypes 1 and 3 differed substantially in this comparison. The Kernow-C1 fecal consensus sequence contains 86 amino acids, compared with 71 for Sar-55.…”

Section: Discussionmentioning

confidence: 95%

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Cross-species infections of cultured cells by hepatitis E virus and discovery of an infectious virus–host recombinant

Shukla

Nguyen

Torian

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

286

335

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The RNA virus, hepatitis E virus (HEV) is the most or second-most important cause of acute clinical hepatitis in adults throughout much of Asia, the Middle East, and Africa. In these regions it is an important cause of acute liver failure, especially in pregnant women who have a mortality rate of 20–30%. Until recently, hepatitis E was rarely identified in industrialized countries, but Hepatitis E now is reported increasingly throughout Western Europe, some Eastern European countries, and Japan. Most of these cases are caused by genotype 3, which is endemic in swine, and these cases are thought to be zoonotically acquired. However, transmission routes are not well understood. HEV that infect humans are divided into nonzoonotic (types 1, 2) and zoonotic (types 3, 4) genotypes. HEV cell culture is inefficient and limited, and thus far HEV has been cultured only in human cell lines. The HEV strain Kernow-C1 (genotype 3) isolated from a chronically infected patient was used to identify human, pig, and deer cell lines permissive for infection. Cross-species infections by genotypes 1 and 3 were studied with this set of cultures. Adaptation of the Kernow-C1 strain to growth in human hepatoma cells selected for a rare virus recombinant that contained an insertion of 174 ribonucleotides (58 amino acids) of a human ribosomal protein gene.

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Section: Discussionmentioning

confidence: 95%

“…The HVR of Sar-55 could be experimentally truncated but not eliminated, suggesting that the sequence per se was not critical (21). The HVRs compared by Pudupakam et al (21) correspond to amino acids 706-792 of Kernow-C1 ORF1.…”

Section: Discussionmentioning

confidence: 96%

Cross-species infections of cultured cells by hepatitis E virus and discovery of an infectious virus–host recombinant

Shukla

Nguyen

Torian

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

286

335

View full text Add to dashboard Cite

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“…For human hepatitis E, HEV infections of monkeys, pigs and chicken have been tested as animal models (Billam et al, 2005;Huang et al, 2007;Pudupakam et al, 2009;Vitral et al, 1998). Recently, HEV infection of BALB/c nude mice carrying a severe Tcell defect was described .…”

Section: Rat Hepatitis E Virusmentioning

confidence: 99%

Detection of a novel hepatitis E-like virus in faeces of wild rats using a nested broad-spectrum RT-PCR

Johne

Plenge‐Bönig

Heß

et al. 2009

Journal of General Virology

328

273

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Hepatitis E is a rare human disease in developed countries. It is caused by hepatitis E virus (HEV), which is probably transmitted zoonotically to humans from domestic pigs and wild boars. Multiple reports on the detection of HEV-specific antibodies in rats have suggested the presence of an HEV-related agent; however, infectious virus or a viral genome has not been demonstrated so far. Here, a nested broad-spectrum RT-PCR protocol was developed capable of detecting different HEV types including those derived from wild boar and chicken. Screening of 30 faecal samples from wild Norway rats (Rattus norvegicus) from Hamburg (Germany) resulted in the detection of two sequences with similarities to human, mammalian and avian HEV. Virus particles with a morphology reminiscent of HEV were demonstrated by immunoelectron microscopy in one of these samples and the virus was tentatively designated rat HEV. Genome fragments with sizes of 4019 and 1545 nt were amplified from two samples. Sequence comparison with human and avian strains revealed only 59.9 and 49.9 % sequence identity, respectively. Similarly, the deduced amino acid sequence for the complete capsid protein had 56.2 and 42.9 % identity with human and avian strains, respectively. Inoculation of the samples onto three different permanent rat liver cell lines did not result in detectable virus replication as assayed by RT-PCR with cells of the fifth virus passage. Further investigations are necessary to clarify the zoonotic potential of rat HEV and to assess its suitability to serve in a laboratory rat animal model for human hepatitis E. INTRODUCTIONHepatitis E, caused by hepatitis E virus (HEV), is a worldwide human disease that is endemic in many developing countries. In industrialized countries, sporadic cases are increasingly reported, which can be traced either to imported infections from endemic regions or to autochthonous HEV infections (Clemente-Casares et al., 2003;Dalton et al., 2008; Gyarmati et al., 2007;Purcell & Emerson, 2008). Hepatitis E is characterized by a selflimiting jaundice of varying severity, which is hard to distinguish from a hepatitis of other viral origin, and is often accompanied by non-specific symptoms such as fever, headache and pain in the upper abdomen. Although the case fatality rate of hepatitis E is low in the general population (0.5-3 %), rates of up to 20 % have been observed for pregnant women (Shrestha et al., 2007;Smith, 2001;Wichmann et al., 2008).HEV is classified as the only member of the genus Hepevirus. This genus is subdivided into four distinct genotypes and the avian HEV strains (Bilic et al., 2009), which are not included in any of the other genotypes. All mammalian HEV isolates described to date comprise the same serotype (Lu et al., 2006;Takahashi et al., 2005). The HEV virion appears as a non-enveloped icosahedral sphere of approximately 27-34 nm in diameter. The crystal structure of HEV-like particles has recently been solved (Yamashita et al., 2009). The particles are composed of a single capsid protein, whic...

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“…The HVR does not appear to be required for the replication of HEV (20). Deletions in the HVR did not abolish HEV infectivity in vivo or in vitro, although deletions of nearly full-length HVR attenuated the virus in animals, suggesting that the HVR may interact with viral and host factors to modulate HEV replication efficiency and/or pathogenesis (21).…”

mentioning

confidence: 95%

The Lysine Residues within the Human Ribosomal Protein S17 Sequence Naturally Inserted into the Viral Nonstructural Protein of a Unique Strain of Hepatitis E Virus Are Important for Enhanced Virus Replication

Kenney

Meng

2015

J Virol

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Hepatitis E virus (HEV) is an important but extremely understudied human pathogen. Due largely to the lack of an efficient cell culture system for HEV, the molecular mechanisms of HEV replication and pathogenesis are poorly understood. Recently, a unique genotype 3 strain of HEV recovered from a chronically infected patient was adapted for growth in HepG2C3A human hepatoma cells. The adaptation of the Kernow C-1 P6 HEV to propagate in HepG2C3A cells selected for a rare virus recombinant that contains an insertion of a 171-nucleotide sequence encoding amino acids 21 to 76 of the human ribosomal protein S17 (RPS17) within the hypervariable region (HVR) of the HEV ORF1 protein. When the RPS17 insertion was placed into a strain of genotype 1 HEV which infects only humans, it expanded the host range of the virus, allowing it to infect cell lines from multiple animal species, including cow, dog, cat, chicken, and hamster. In this study, we utilized forward and reverse genetics to attempt to define which aspects of the RPS17 insertion allow for the ability of the Kernow C-1 P6 HEV to adapt in cell culture and allow for expanded host tropism. We demonstrate that the RPS17 sequence insertion in HEV bestows novel nuclear/nucleolar trafficking capabilities to the ORF1 protein of Kernow P6 HEV and that lysine residues within the RPS17 insertion, but not nuclear localization of the ORF1 protein, correlate with the enhanced replication of the HEV Kernow C-1 P6 strain. The results from this study have important implications for understanding the mechanism of cross-species infection and replication of HEV. IMPORTANCEHEV is an important pathogen worldwide. The virus causes high mortality (up to 30%) in pregnant women and has been recognized to cause chronic hepatitis in immunocompromised populations. The life cycle of HEV has been understudied due to a lack of sufficient cell culture systems in which to propagate the virus. Recently, insertions and rearrangements of the hypervariable region (HVR) within the HEV genome, allowing for cell culture adaptation and expansion of the host range, have been reported. We utilized these cell culture-adapted HEV strains to assess how the HVR may be involved in virus replication and host range. We provide evidence that insertion of the RPS17 sequence in HEV likely confers nuclear trafficking capabilities to the nonstructural protein of the virus and that lysine residues within the RPS17 insertion are important for enhanced replication of the virus. These data will help to elucidate the mechanism of cross-species infection of HEV in the future. Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in many parts of the world (1, 2). Major outbreaks and epidemics are most common in developing countries, where a lack of proper sanitation conditions leads to waterborne spread of the disease. In industrialized countries, HEV infection is typically sporadic and endemic. Recently, chronic HEV infection has become an important clinical problem in immunosuppressed individual...

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Deletions of the Hypervariable Region (HVR) in Open Reading Frame 1 of Hepatitis E Virus Do Not Abolish Virus Infectivity: Evidence for Attenuation of HVR Deletion Mutants In Vivo

Abstract: Hepatitis E virus (HEV) is an important human pathogen

Cited by 88 publications

References 59 publications

Cross-species infections of cultured cells by hepatitis E virus and discovery of an infectious virus–host recombinant

Cross-species infections of cultured cells by hepatitis E virus and discovery of an infectious virus–host recombinant

Detection of a novel hepatitis E-like virus in faeces of wild rats using a nested broad-spectrum RT-PCR

The Lysine Residues within the Human Ribosomal Protein S17 Sequence Naturally Inserted into the Viral Nonstructural Protein of a Unique Strain of Hepatitis E Virus Are Important for Enhanced Virus Replication

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