1887

Abstract

Hepatitis E virus (HEV) replication has been demonstrated in HepG2 cells transfected with full-length transcripts of an infectious cDNA clone. This cDNA clone was modified to generate several subgenomic HEV replicons with fused reporter genes. -transcribed capped RNAs generated from these were transfected into HepG2 cells. Negative-strand RNA was detected, indicating the occurrence of replication. The replicon containing an in-frame fusion of HEV ORF2 with enhanced green fluorescent protein (EGFP) was positive for fluorescence, whereas no signal was observed when the replicase domain was deleted. An HEV ORF3–EGFP in-frame fusion did not yield fluorescence. Deletions introduced into ORF2 did not affect the replication competency of the viral RNA. To explore the possibility of using a reporter-gene assay to monitor the synthesis of plus- and minus-strand RNA, the EGFP gene fused to the encephalomyocarditis virus internal ribosome entry site (IRES) was inserted into partially deleted ORF2 of HEV, in both the sense [HEV–IRES–EGFP(+)] and antisense [HEV–IRES–EGFP(−)] orientations. HepG2 cells transfected with HEV–IRES–EGFP(+) and HEV–IRES–EGFP(−) vectors were positive for EGFP fluorescence. To quantify HEV replication, EGFP was replaced with Renilla luciferase (RLuc). HEV–IRES–RLuc(+) showed approximately 10-fold higher luminescence than HEV–IRES–RLuc(−). There was complete loss of activity when the helicase–replicase domain in HEV–IRES–RLuc(−) was deleted. A short-term HepG2 cell line containing the full-length viral genome in the pcDNA3 vector was established. Viral RNA and proteins (RdRp, pORF2 and pORF3) could be detected in the geneticin-resistant cells, even after the seventh passage. In the absence of a reliable cell-culture system to study HEV biology, these reporter replicons, as well as the cell line, bestow immense utility.

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2005-04-01
2024-04-28
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References

  1. Agrawal S., Gupta D., Panda S. K. 2001; The 3′ end of hepatitis E virus (HEV) genome binds specifically to the viral RNA-dependent RNA polymerase (RdRp. Virology 282:87–101 [CrossRef]
    [Google Scholar]
  2. Bradley D. W. 1990; Enterically transmitted non-A, non-B hepatitis. Br Med Bull 46:442–461
    [Google Scholar]
  3. Clayson E. T., Innis B. L., Myint K. S., Narupiti S., Vaughn D. W., Giri S., Ranabhat P., Shrestha M. P. 1995; Detection of hepatitis E virus infections among domestic swine in the Kathmandu Valley of Nepal. Am J Trop Med Hyg 53:228–232
    [Google Scholar]
  4. Dawson G. J., Mushahwar I. K., Chau K. H., Gitnick G. L. 1992; Detection of long-lasting antibody to hepatitis E virus in a US traveller to Pakistan. Lancet 340:426–427
    [Google Scholar]
  5. Emerson S. U., Zhang M., Meng X.-J., Nguyen H., St Claire M., Govindarajan S., Huang Y. K., Purcell R. H. 2001; Recombinant hepatitis E virus genomes infectious for primates: importance of capping and discovery of a cis-reactive element. Proc Natl Acad Sci U S A 98:15270–15275 [CrossRef]
    [Google Scholar]
  6. Emerson S. U., Nguyen H., Graff J., Stephany D. A., Brockington A., Purcell R. H. 2004; In vitro replication of hepatitis E virus (HEV) genomes and of an HEV replicon expressing green fluorescent protein. J Virol 78:4838–4846 [CrossRef]
    [Google Scholar]
  7. Garkavenko O., Obriadina A., Meng J., Anderson D. A., Benard H. J., Schroeder B. A., Khudyakov Y. E., Fields H. A., Croxson M. C. 2001; Detection and characterisation of swine hepatitis E virus in New Zealand. J Med Virol 65:525–529 [CrossRef]
    [Google Scholar]
  8. Hsieh S.-Y., Meng X.-J., Wu Y.-H., Liu S.-T., Tam A. W., Lin D.-Y., Liaw Y.-F. 1999; Identity of a novel swine hepatitis E virus in Taiwan forming a monophyletic group with Taiwan isolates of human hepatitis E virus. J Clin Microbiol 37:3828–3834
    [Google Scholar]
  9. Jameel S., Zafrullah M., Ozdener M. H., Panda S. K. 1996; Expression in animal cells and characterization of the hepatitis E virus structural proteins. J Virol 70:207–216
    [Google Scholar]
  10. Kabrane-Lazizi Y., Meng X.-J., Purcell R. H., Emerson S. U. 1999; Evidence that the genomic RNA of hepatitis E virus is capped. J Virol 73:8848–8850
    [Google Scholar]
  11. Khromykh A. A., Westaway E. G. 1997; Subgenomic replicons of the flavivirus Kunjin: construction and applications. J Virol 71:1497–1505
    [Google Scholar]
  12. Khuroo M. S. 1980; Study of an epidemic of non-A, non-B hepatitis: possibility of another human hepatitis virus distinct from post-transfusion non-A, non-B type. Am J Med 68:818–824 [CrossRef]
    [Google Scholar]
  13. Koonin E. V., Gorbalenya A. E., Purdy M. A., Rozanov M. N., Reyes G. R., Bradley D. W. 1992; Computer-assisted assignment of functional domains in the nonstructural polyprotein of hepatitis E virus: delineation of an additional group of positive-strand RNA plant and animal viruses. Proc Natl Acad Sci U S A 89:8259–8263 [CrossRef]
    [Google Scholar]
  14. Korkaya H., Jameel S., Gupta D. 9 other authors 2001; The ORF3 protein of hepatitis E virus binds to Src homology 3 domains and activates MAPK. J Biol Chem 276:42389–42400 [CrossRef]
    [Google Scholar]
  15. Levis R., Schlesinger S., Huang H. V. 1990; Promoter for Sindbis virus RNA-dependent subgenomic RNA transcription. J Virol 64:1726–1733
    [Google Scholar]
  16. Liljestrom P., Garoff H. 1991; A new generation of animal cell expression vectors based on the Semliki Forest virus replicon. Biotechnology 9:1356–1361 [CrossRef]
    [Google Scholar]
  17. Magden J., Takeda N., Li T., Auvinen P., Ahola T., Miyamura T., Merits A., Kääriäinen L. 2001; Virus-specific mRNA capping enzyme encoded by hepatitis E virus. J Virol 75:6249–6255 [CrossRef]
    [Google Scholar]
  18. Meng X.-J., Purcell R. H., Halbur P. G., Lehman J. R., Webb D. M., Tsareva T. S., Haynes J. S., Thacker B. J., Emerson S. U. 1997; A novel virus in swine is closely related to the human hepatitis E virus. Proc Natl Acad Sci U S A 94:9860–9865 [CrossRef]
    [Google Scholar]
  19. Meng X. J., Halbur P. G., Shapiro M. S., Govindarajan S., Bruna J. D., Mushahwar I. K., Purcell R. H., Emerson S. U. 1998; Genetic and experimental evidence for cross-species infection by swine hepatitis E virus. J Virol 72:9714–9721
    [Google Scholar]
  20. Nanda S. K., Panda S. K., Durgapal H., Jameel S. 1994; Detection of the negative strand of hepatitis E virus RNA in the livers of experimentally infected rhesus monkeys: evidence for viral replication. J Med Virol 42:237–240 [CrossRef]
    [Google Scholar]
  21. Nishizawa T., Takahashi M., Mizuo H., Miyajima H., Gotanda Y., Okamoto H. 2003; Characterization of Japanese swine and human hepatitis E virus isolates of genotype IV with 99 % identity over the entire genome. J Gen Virol 84:1245–1251 [CrossRef]
    [Google Scholar]
  22. Ooi W. W., Gawoski J. M., Yarbough P. O., Pankey G. A. 1999; Hepatitis E seroconversion in United States travelers abroad. Am J Trop Med Hyg 61:822–824
    [Google Scholar]
  23. Panda S. K., Ansari I. H., Durgapal H., Agrawal S., Jameel S. 2000; The in vitro-synthesized RNA from a cDNA clone of hepatitis E virus is infectious. J Virol 74:2430–2437 [CrossRef]
    [Google Scholar]
  24. Polo J. M., Belli B. A., Driver D. A. 10 other authors 1999; Stable alphavirus packaging cell lines for Sindbis virus- and Semliki Forest virus-derived vectors. Proc Natl Acad Sci U S A 96:4598–4603 [CrossRef]
    [Google Scholar]
  25. Purcell R. H., Ticehurst J. R. 1988; Enterically transmitted non-A, non-B hepatitis: epidemiology and clinical characteristics. In Viral Hepatitis and Liver Diseases pp  131–137 Edited by Zuckerman A. J. New York: Wiley-Liss;
    [Google Scholar]
  26. Purdy M. A., Tam A. W., Huang C. C., Yarbough P. O., Reyes G. R. 1993; Hepatitis E virus: a non-enveloped member of the ‘alpha-like’ RNA virus supergroup?. Semin Virol 4:319–326 [CrossRef]
    [Google Scholar]
  27. Shi P.-Y., Tilgner M., Lo M. K. 2002; Construction and characterization of subgenomic replicons of New York strain of West Nile virus. Virology 296:219–233 [CrossRef]
    [Google Scholar]
  28. Skidmore S. J., Sherratt L. M. 1996; Hepatitis E infection in the UK. J Viral Hepat 3:103–105 [CrossRef]
    [Google Scholar]
  29. Skidmore S. J., Yarbough P. O., Gabor K. A., Tam A. W., Reyes G. R., Flower A. J. E. 1991; Imported hepatitis E in UK. Lancet 337:1541 [CrossRef]
    [Google Scholar]
  30. Song C., Simon A. E. 1995; Requirement of a 3′-terminal stem-loop in in vitro transcription by an RNA-dependent RNA polymerase. J Mol Biol 254:6–14 [CrossRef]
    [Google Scholar]
  31. Sriram B., Thakral D., Panda S. K. 2003; Targeted cleavage of hepatitis E virus 3′ end RNA mediated by hammerhead ribozymes inhibits viral RNA replication. Virology 312:350–358 [CrossRef]
    [Google Scholar]
  32. Tam A. W., Smith M. M., Guerra M. E., Huang C.-C., Bradley D. W., Fry K. E., Reyes G. R. 1991; Hepatitis E virus (HEV): molecular cloning and sequencing of the full-length viral genome. Virology 185:120–131 [CrossRef]
    [Google Scholar]
  33. Tokita H., Harada H., Gotanda Y., Takahashi M., Nishizawa T., Okamoto H. 2003; Molecular and serological characterization of sporadic acute hepatitis E in a Japanese patient infected with a genotype III hepatitis E virus in 1993. J Gen Virol 84:421–427 [CrossRef]
    [Google Scholar]
  34. Torresi J., Li F., Locarnini S. A., Anderson D. A. 1999; Only the non-glycosylated fraction of hepatitis E virus capsid (open reading frame 2) protein is stable in mammalian cells. J Gen Virol 80:1185–1188
    [Google Scholar]
  35. Wong D. C., Purcell R. H., Sreenivasan M. A., Prasad S. R., Pavri K. M. 1980; Epidemic and endemic hepatitis in India: evidence for a non-A, non-B hepatitis virus aetiology. Lancet ii:876–879
    [Google Scholar]
  36. Wu J.-C., Sheen I.-J., Chiang T.-Y., Sheng W.-Y., Wang Y.-J., Chan C.-Y., Lee S.-D. 1998; The impact of traveling to endemic areas on the spread of hepatitis E virus infection: epidemiological and molecular analyses. Hepatology 27:1415–1420 [CrossRef]
    [Google Scholar]
  37. Xia X., Huang R., Li D. 2000; Studies on the subgenomic RNAs of hepatitis E virus. Wei Sheng Wu Xue Bao 40:622–627 (in Chinese
    [Google Scholar]
  38. Xiong C., Levis R., Shen P., Schlesinger S., Rice C. M., Huang H. V. 1989; Sindbis virus: an efficient, broad host range vector for gene expression in animal cells. Science 243:1188–1191 [CrossRef]
    [Google Scholar]
  39. Zafrullah M., Ozdener M. H., Panda S. K., Jameel S. 1997; The ORF3 protein of hepatitis E virus is a phosphoprotein that associates with the cytoskeleton. J Virol 71:9045–9053
    [Google Scholar]
  40. Zafrullah M., Ozdener M. H., Kumar R., Panda S. K., Jameel S. 1999; Mutational analysis of glycosylation, membrane translocation, and cell surface expression of the hepatitis E virus ORF2 protein. J Virol 73:4074–4082
    [Google Scholar]
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