scholarly journals Biliary Secretion of Quasi-Enveloped Human Hepatitis A Virus

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Asuka Hirai-Yuki ◽  
Lucinda Hensley ◽  
Jason K. Whitmire ◽  
Stanley M. Lemon
Keyword(s):  
Life Cycle ◽  
Bile Acids ◽  
Neutralizing Antibodies ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Acute Infection ◽  
Cell Culture Supernatant ◽  
Particle Type ◽  
Human Bile

ABSTRACTHepatitis A virus (HAV) is an unusual picornavirus that is released from cells cloaked in host-derived membranes. These quasi-enveloped virions (eHAV) are the only particle type circulating in blood during infection, whereas only nonenveloped virions are shed in feces. The reason for this is uncertain. Hepatocytes, the only cell type known to support HAV replicationin vivo, are highly polarized epithelial cells with basolateral membranes facing onto hepatic (blood) sinusoids and apical membranes abutting biliary canaliculi from which bile is secreted to the gut. To assess whether eHAV and nonenveloped virus egress from cells via vectorially distinct pathways, we studied infected polarized cultures of Caco-2 and HepG2-N6 cells. Most (>99%) progeny virions were released apically from Caco-2 cells, whereas basolateral (64%) versus apical (36%) release was more balanced with HepG2-N6 cells. Both apically and basolaterally released virions were predominantly enveloped, with no suggestion of differential vectorial release of eHAV versus naked virions. Basolateral to apical transcytosis of either particle type was minimal (<0.02%/h) in HepG2-N6 cells, arguing against this as a mechanism for differences in membrane envelopment of serum versus fecal virus. High concentrations of human bile acids converted eHAV to nonenveloped virions, whereas virus present in bile from HAV-infectedIfnar1−/−Ifngr1−/−andMavs−/−mice banded over a range of densities extending from that of eHAV to that of nonenveloped virions. We conclude that nonenveloped virions shed in feces are derived from eHAV released across the canalicular membrane and stripped of membranes by the detergent action of bile acids within the proximal biliary canaliculus.IMPORTANCEHAV is a hepatotropic, fecally/orally transmitted picornavirus that can cause severe hepatitis in humans. Recent work reveals that it has an unusual life cycle. Virus is found in cell culture supernatant fluids in two mature, infectious forms: one wrapped in membranes (quasi-enveloped) and another that is nonenveloped. Membrane-wrapped virions circulate in blood during acute infection and are resistant to neutralizing antibodies, likely facilitating HAV dissemination within the liver. On the other hand, virus shed in feces is nonenveloped and highly stable, facilitating epidemic spread and transmission to naive hosts. Factors controlling the biogenesis of these two distinct forms of the virus in infected humans are not understood. Here we characterize vectorial release of quasi-enveloped virions from polarized epithelial cell cultures and provide evidence that bile acids strip membranes from eHAV following its secretion into the biliary tract. These results enhance our understanding of the life cycle of this unusual picornavirus.

In Vivo Replication and Reversion to Wild Type of a Neutralization-Resistant Antigenic Variant of Hepatitis A Virus

1990 ◽  
Vol 161 (1) ◽  
pp. 7-13 ◽  
Author(s):  
S. M. Lemon ◽  
L. N. Binn ◽  
R. Marchwicki ◽  
P. C. Murphy ◽  
L.-H. Ping ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Wild Type ◽  
Antigenic Variant

Iminosugar glucosidase inhibitors reduce hepatic inflammation in HAV-infected Ifnar1-/- mice

2021 ◽  
Author(s):  
Ichiro Misumi ◽  
Zhucui Li ◽  
Lu Sun ◽  
Anshuman Das ◽  
Tomoyuki Shiota ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Cell Entry ◽  
Cytokine Receptors ◽  
Potential Importance ◽  
Paracrine Signaling ◽  
Acute Hepatitis A ◽  
Anti Inflammatory ◽  
High Doses

Iminosugar compounds are monosaccharide mimetics with broad but generally weak antiviral activities related to inhibition of enzymes involved in glycobiology. Miglustat (N-butyl-1-deoxynojirimycin), which is approved for treatment of lipid storage diseases in humans, and UV-4 (N-(9-methoxynonyl)-1-deoxynojirimycin), inhibit replication of hepatitis A virus (HAV) in cell culture (IC50 32.13 μM and 8.05 μM, respectively) by blocking the synthesis of gangliosides essential for HAV cell entry. We used a murine model of hepatitis A and targeted mass spectrometry to assess the capacity of these compounds to deplete hepatic gangliosides and modify the course of HAV infection in vivo. Miglustat, given by gavage to Ifnar1-/- mice (4800 mg/kg/day) depleted hepatic gangliosides by 69-75%, but caused substantial gastrointestinal toxicity and failed to prevent viral infection. UV-4, similarly administered in high doses (400 mg/kg/day), was well tolerated, but depleted hepatic gangliosides by only 20% after 14 days. UV-4 depletion of gangliosides varied by class. Several GM2 species were paradoxically increased, likely due to inhibition of β-glucosidases that degrade gangliosides. Both compounds enhanced, rather than reduced, virus replication. Nonetheless, both iminosugars had surprising anti-inflammatory effects, blocking the accumulation of inflammatory cells within the liver. UV-4 treatment also resulted in a decrease in serum alanine aminotransferase (ALT) elevations associated with acute hepatitis A. These anti-inflammatory effects may result from iminosugar inhibition of cellular α-glucosidases, leading to impaired maturation of glycan moieties of chemokine and cytokine receptors, and point to the potential importance of paracrine signaling in the pathogenesis of acute hepatitis A. IMPORTANCE Hepatitis A virus (HAV) is a common cause of viral hepatitis. Iminosugar compounds block its replication in cultured cells by inhibiting synthesis of gangliosides required for HAV cell entry, but have not been tested for their ability to prevent or treat hepatitis A in vivo. We show that high doses of the iminosugars miglustat and UV-4 fail to deplete gangliosides sufficiently to block HAV infection in mice lacking a key interferon receptor. These compounds nonetheless have striking anti-inflammatory effects on the HAV-infected liver, reducing the severity of hepatitis despite enhancing chemokine and cytokine expression resulting from hepatocyte-intrinsic antiviral responses. We propose that iminosugar inhibition of cellular α-glucosidases impairs maturation of glycan moieties of chemokine and cytokine receptors required for effective signaling. These data highlight the potential importance of paracrine signaling pathways in the inflammatory response to HAV, and add to our understanding of HAV pathogenesis in mice.

Hepatitis a virus: Growth characteristics of in vivo and in vitro propagated wild and attenuated virus strains

1984 ◽  
Vol 14 (4) ◽  
pp. 373-386 ◽  
Author(s):  
Daniel W. Bradley ◽  
Charles A. Schable ◽  
Karen A. McCaustland ◽  
E. H. Cook ◽  
Bert L. Murphy ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Growth Characteristics ◽  
Virus Growth ◽  
Attenuated Virus ◽  
Virus Strains

scholarly journals Degradation of the encephalomyocarditis virus and hepatitis A virus 3C proteases by the ubiquitin/26S proteasome system in vivo

Virology ◽  
2007 ◽  
Vol 360 (2) ◽  
pp. 350-363 ◽  
Author(s):  
Peter E. Schlax ◽  
Jin Zhang ◽  
Elizabeth Lewis ◽  
Antonio Planchart ◽  
T. Glen Lawson
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Encephalomyocarditis Virus ◽  
26S Proteasome

scholarly journals Hepatitis A virus proteinase 3C binding to viral RNA: correlation with substrate binding and enzyme dimerization

2005 ◽  
Vol 385 (2) ◽  
pp. 363-370 ◽  
Author(s):  
Hannelore PETERS ◽  
Yuri Y. KUSOV ◽  
Sonja MEYER ◽  
Andrew J. BENIE ◽  
Englbert BÄUML ◽  
...  
Keyword(s):  
Life Cycle ◽  
Proteolytic Activity ◽  
Hepatitis A ◽  
Kinetic Resolution ◽  
Rna Binding ◽  
Hepatitis A Virus ◽  
Viral Life Cycle ◽  
Binding Kinetics ◽  
Viral Rna ◽  
Binding Studies

Proteinase 3C of hepatitis A virus (HAV) plays a key role in the viral life cycle by generating mature viral proteins from the precursor polyprotein. In addition to its proteolytic activity, 3C binds to viral RNA, and thus influences viral genome replication. In order to investigate the interplay between proteolytic activity and RNA binding at the molecular level, we subjected HAV 3C and three variants carrying mutations of the cysteine residues [C24S (Cys-24→Ser), C172A and C24S/C172A] to proteolysis assays with peptide substrates, and to surface plasmon resonance binding studies with peptides and viral RNA. We report that the enzyme readily forms dimers via disulphide bridges involving Cys-24. Dissociation constants (KD) for peptides were in the millimolar range. The binding kinetics for the peptides were characterized by kon and koff values of the order of 102 M−1·s−1 and 10−2 to 10−1 s−1 respectively. In contrast, 3C binding to immobilized viral RNA, representing the structure of the 5′-terminal domain, followed fast binding kinetics with kon and koff values beyond the limits of the kinetic resolution of the technique. The affinity of viral RNA depended strongly on the dimerization status of 3C. Whereas monomeric 3C bound to the viral RNA with a KD in the millimolar range, dimeric 3C had a significantly increased binding affinity with KD values in the micromolar range. A model of the 3C dimer suggests that spatial proximity of the presumed RNA-binding motifs KFRDI is possible. 3C binding to RNA was also promoted in the presence of substrate peptides, indicating co-operativity between RNA binding and protease activity. The data imply that the dual functions of 3C are mutually dependent, and regulate protein and RNA synthesis during the viral life cycle.

Localization of Hepatitis A Antigen in Marmoset Organs during Acute Infection with Hepatitis A Virus

1978 ◽  
Vol 138 (3) ◽  
pp. 369-377 ◽  
Author(s):  
L. R. Mathiesen ◽  
J. Drucker ◽  
D. Lorenz ◽  
J. Wagner ◽  
R. J. Gerety ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Acute Infection

scholarly journals Hepatitis A Virus-Specific Immunoglobulin A Mediates Infection of Hepatocytes with Hepatitis A Virus via the Asialoglycoprotein Receptor

2000 ◽  
Vol 74 (23) ◽  
pp. 10950-10957 ◽  
Author(s):  
Andreas Dotzauer ◽  
Ulrike Gebhardt ◽  
Karen Bieback ◽  
Ulrich Göttke ◽  
Anja Kracke ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Neutralizing Antibodies ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Immunoglobulin A ◽  
Asialoglycoprotein Receptor ◽  
Primary Hepatocytes ◽  
Mouse Hepatocyte ◽  
Specific Immunoglobulin ◽  
Bile Fluid

ABSTRACT The mechanisms underlying the hepatotropism of hepatitis A virus (HAV) and the relapsing courses of HAV infections are unknown. In this report, we show for a mouse hepatocyte model that HAV-specific immunoglobulin A (IgA) mediates infection of hepatocytes with HAV via the asialoglycoprotein receptor, which binds and internalizes IgA molecules. Proof of HAV infection was obtained by detection of HAV minus-strand RNA, which is indicative for virus replication, and quantification of infectious virions. We demonstrate that human hepatocytes also ingest HAV–anti-HAV IgA complexes by the same mechanism, resulting in infection of the cells, by using the HepG2 cell line and primary hepatocytes. The relevance of this surrogate receptor mechanism in HAV pathogenesis lies in the fact that HAV, IgA, and antigen-IgA complexes use the same pathway within the organism, leading from the gastrointestinal tract to the liver via blood and back to the gastrointestinal tract via bile fluid. Therefore, HAV-specific IgA antibodies produced by gastrointestinal mucosa-associated lymphoid tissue may serve as carrier and targeting molecules, enabling and supporting HAV infection of IgA receptor-positive hepatocytes and, in the case of relapsing courses, allowing reinfection of the liver in the presence of otherwise neutralizing antibodies, resulting in exacerbation of liver disease.

scholarly journals In Vivo Study of the HC-TN Strain of Hepatitis C Virus Recovered from a Patient with Fulminant Hepatitis: RNA Transcripts of a Molecular Clone (pHC-TN) Are Infectious in Chimpanzees but Not in Huh7.5 Cells

2007 ◽  
Vol 81 (13) ◽  
pp. 7208-7219 ◽  
Author(s):  
Akito Sakai ◽  
Shingo Takikawa ◽  
Robert Thimme ◽  
Jean-Christophe Meunier ◽  
Hans Christian Spangenberg ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Responses ◽  
Disease Severity ◽  
Neutralizing Antibodies ◽  
Viral Evolution ◽  
Acute Infection ◽  
Hcv Infection ◽  
Rna Transcripts

ABSTRACT Both viral and host factors are thought to influence the pathogenesis of hepatitis C virus (HCV) infection. We studied strain HC-TN (genotype 1a), which caused fulminant hepatic failure in a patient and, subsequently, severe hepatitis in a chimpanzee (CH1422), to analyze the relationship between disease severity, host immune response, viral evolution, and outcome. A second chimpanzee (CH1581) was infected from CH1422 plasma, and a third chimpanzee (CH1579) was infected from RNA transcripts of a consensus cDNA of HC-TN (pHC-TN). RNA transcripts of pHC-TN did not replicate in Huh7.5 cells, which were recently found to be susceptible to infection with another fulminant HCV strain (JFH1). The courses of viremia were similar in the three animals. However, CH1581 and CH1579 developed a less severe acute hepatitis than CH1422. CH1579 and CH1422 resolved the infection, whereas CH1581 became persistently infected. CH1579 and CH1581, despite their differing outcomes, both developed significant intrahepatic cellular immune responses, but not antibodies to the envelope glycoproteins or neutralizing antibodies, during the acute infection. We analyzed the polyprotein sequences of virus recovered at five and nine time points from CH1579 and CH1581, respectively, during the first year of follow-up. High mutation rates and high proportions of nonsynonymous mutations suggested immune pressure and positive selection in both animals. Changes were not selected until after the initial decrease in virus titers and after the development of immune responses and hepatitis. Subsequently, however, mutations emerged repeatedly in both animals. Overall, our results indicate that disease severity and outcome of acute HCV infection depend primarily on the host response.

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