Experimental Hepatitis E: Pathogenesis in Cynomolgus Macaques (Macaca fascicularis)

Longer, Charles F.; Denny, Stephen L.; Caudill, Jeffrey D.; Miele, Thomas A.; Asher, Ludmila V.; Myint, Khin Saw Aye; Huang, Chiao Chain; Engler, W.F.; LeDuc, James W.; Binn, Leonard N.; Ticehurst, John R.

doi:10.1093/infdis/168.3.602

Cited by 51 publications

(29 citation statements)

References 31 publications

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“…Similar findings including hepatocyte necrosis, inflammatory cell and lymphocyte infiltration, Kupffer cell hypertrophy, and singlecell necrosis have been described in other studies of experimental hepatitis E [Bradley et al, 1987, Andzhaparidze et al, 1986Krawczynski et al, 1989;Longer et al, 1993;Soe et al, 1989;Ticehurst et al, 1992;Tsarev et al, 1993aTsarev et al, , 1993b. The findings were consistent with, but no specific to hepatitis E. The observation of increased hepatocyte fat (554A) was nonspecific but has been reported in other studies [Longer et al, 1993;Ticehurst et al, 1992].…”

Section: Discussionsupporting

confidence: 86%

Experimental African HEV infection in cynomolgus macaques (Macaca fascicularis)

et al. 1998

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Experimental infection with hepatitis E virus (HEV) from Africa has not been investigated. Our purpose was to study hepatitis E produced by HEV from Chad (North Africa) and to analyze the genetic sequence of the HEV obtained after animal passage. An HEV-containing fecal sample from Chad was intravenously inoculated in four cynomolgus macaques. When serum Alanine Amino Transferase (ALT) levels rose, open liver biopsy and bile aspiration were performed. In all the monkeys, an ALT rise occurred 25 to 32 days after inoculation and new anti-HEV was detected by Enzyme Immuno Assay (EIA). Hepatic histopathology was consistent with acute viral hepatitis. HEV was detected by polymerase chain reaction (PCR) in bile (3/4 animals) and feces (2/4 animals) and by imunoelectron microscopy (IEM) in the inoculum and one bile specimen. A genetic variant HEV was identified in one monkey. The Chad HEV produced hepatitis E with pathophysiologic and histopathologic findings similar to those observed with HEV from other geographic origins. A genomic variant HEV population was produced after one passage in a macaque.

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Section: Discussionsupporting

confidence: 86%

Experimental African HEV infection in cynomolgus macaques (Macaca fascicularis)

et al. 1998

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“…The genome contains three open reading frames (ORFs) with ORF2 encoding the putative major structural or capsid protein. The cloning of geographically distinct strains of HEV and synthesis of recombinant HEV proteins [Reyes et al, 1990;Ichikawa et al, 1991;Tam et al, 1991;Yarbough et al, 1991;Aye et al, 1992;Huang et al, 1992;Uchida et al, 1992;He et al, 1993;Li et al, 1994] along with the development of animal models for HE infection [Gupta et al, 1990;Bradley, 1992;Jameel et al, 1992;Tsarev et al, 1992Tsarev et al, , 1995Arankalle et al, 1993;Longer et al, 1993] have made it possible to study antigenic and immunogenic epitopes of HEV proteins. In addition, the expression of ORF2 and ORF3 proteins in E. coli and Baculovirus systems, and the production of synthetic peptides have led to the development of diagnostic assays He et al, 1993;Yarbough et al, 1993;Paul et al, 1994].…”

Section: Introductionmentioning

confidence: 99%

Amino-terminal epitopes are exposed when full-length open reading frame 2 of hepatitis E virus is expressed inEscherichia coli, but carboxy-terminal epitopes are masked

et al. 1997

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We constructed a panel of overlapping and non-overlapping fragments of cDNA derived from open reading frame 2 (ORF2) of hepatitis E virus (HEV) and fused to the gene encoding glutathione S-transferase (GST), from which proteins were expressed in Escherichia coli. IgG-specific immunoreactivity against each protein was measured by Western immunoblotting using sera from experimentally infected Rhesus macaques (Macaca mulatta) or from HEV-infected patients. Under these conditions, full-length ORF2 protein (GST-ORF2) was strongly reactive with acute-phase sera from either macaques or patients, but was poorly reactive with convalescent sera. Recombinant protein GST-ORF2.3, representing amino acids 1-110 of the 660 encoded by ORF2, demonstrated a pattern of reactivity largely indistinguishable from the full-length protein. Conversely, GST-ORF2.1, representing amino acids 394-660 of the ORF2 protein was strongly reactive with both acute- and convalescent-phase sera. Extension of GST-ORF2.1 towards the N-terminus led to a progressive loss of convalescent-phase reactivity, apparent with as few as 20 additional HEV-specific amino acids. Deletion of 40 or more amino acids from the N-terminus of ORF2.1 also led to reduced convalescent-phase reactivity, however a protein representing this "reactive" region, containing amino acids 394-473, was poorly reactive, suggesting that the convalescent-reactive epitopes are conformational. Expression of full-length ORF2 protein in E. coli therefore masks the convalescent-reactive epitopes within the C-terminal part of the protein, without affecting N-terminal, acute-reactive epitopes.

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“…It was presumed that antibody or other component of the host immune response is mediating the clearance of virus and infected cells thereby causing more prominent histopathologic changes. 104 This idea was further supported by the presence of infiltrating lymphocytes of a cytotoxic/suppressor immunophenotype suggesting a cell-mediated immune mechanism for hepatocytes damage during HEV infection. The findings of several recent studies favored the proposal of HEV pathogenesis to be immune mediated.…”

Section: Pathogenesismentioning

confidence: 92%

Hepatitis E: Molecular Virology and Pathogenesis

Panda

Varma

2013

Journal of Clinical and Experimental Hepatology

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Hepatitis E virus is a single, positive-sense, capped and poly A tailed RNA virus classified under the family Hepeviridae. Enteric transmission, acute self-limiting hepatitis, frequent epidemic and sporadic occurrence, high mortality in affected pregnants are hallmarks of hepatitis E infection. Lack of an efficient culture system and resulting reductionist approaches for the study of replication and pathogenesis of HEV made it to be a less understood agent. Early studies on animal models, sub-genomic expression of open reading frames (ORF) and infectious cDNA clones have helped in elucidating the genome organization, important stages in HEV replication and pathogenesis. The genome contains three ORF's and three untranslated regions (UTR). The 5 0 distal ORF, ORF1 is translated by host ribosomes in a cap dependent manner to form the non-structural polyprotein including the viral replicase. HEV replicates via a negative-sense RNA intermediate which helps in the formation of the positive-sense genomic RNA and a single bi-cistronic sub-genomic RNA. The 3 0 distal ORF's including the major structural protein pORF2 and the multifunctional host interacting protein pORF3 are translated from the sub-genomic RNA. Pathogenesis in HEV infections is not well articulated, and remains a concern due to the many aspects like host dependent and genotype specific variations. Animal HEV, zoonosis, chronicity in immunosuppressed patients, and rapid decompensation in affected chronic liver diseased patients warrants detailed investigation of the underlying pathogenesis. Recent advances about structure, entry, egress and functional characterization of ORF1 domains has furthered our understanding about HEV. This article is an effort to review our present understanding about molecular biology and pathogenesis of HEV. ( J CLIN EXP HEPATOL 2013;3:114-124) H epatitis E virus was first identified in 1983 as the agent responsible for the large scale waterborne epidemics of acute, self-limiting hepatitis in developing nations.1 It was shown to be a naked 28-34 nm virus-like particle with spikes and inundations. 1,2Successful use of non-human primate models for HEV propagation helped in its isolation, cloning and sequencing and as presumed turned out to be an RNA virus.3,4 It had a $7.2 kb single stranded genome with sequence homology to other positive-sense RNA viruses. 4,5 Computer based genome annotation revealed three overlapping open reading frames ORF1, ORF2 and ORF3.4,5 The longest ORF, ORF1 formed the 5 0 distal end of the genome and coded for the non-structural replication proteins including methyltransferase, protease, helicase, and RNA dependent RNA polymerase (RdRp). The 30 distal ORF, ORF2 coded for an arginine rich protein, together with immunodominant sero-reactivity and agglutination against the expressed epitopes, it was predicted to be the major structural protein. A third ORF, ORF3 coded for a small protein thought to be a minor structural protein. [4][5][6] Molecular characterization and replication model of HEV remained...

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Experimental Hepatitis E: Pathogenesis in Cynomolgus Macaques (Macaca fascicularis)

Cited by 51 publications

References 31 publications

Experimental African HEV infection in cynomolgus macaques (Macaca fascicularis)

Experimental African HEV infection in cynomolgus macaques (Macaca fascicularis)

Amino-terminal epitopes are exposed when full-length open reading frame 2 of hepatitis E virus is expressed inEscherichia coli, but carboxy-terminal epitopes are masked

Hepatitis E: Molecular Virology and Pathogenesis

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