scholarly journals Duck Hepatitis B Virus Requires Cholesterol for Endosomal Escape during Virus Entry

2008 ◽  
Vol 82 (21) ◽  
pp. 10532-10542 ◽  
Author(s):  
Anneke Funk ◽  
Mouna Mhamdi ◽  
Heinz Hohenberg ◽  
Jörg Heeren ◽  
Rudolph Reimer ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Biological Membranes ◽  
Endosomal Escape ◽  
Cholesterol Depletion ◽  
Virus Infectivity ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
Viral Particles ◽  
B Virus

ABSTRACT The identity and functionality of biological membranes are determined by cooperative interaction between their lipid and protein constituents. Cholesterol is an important structural lipid that modulates fluidity of biological membranes favoring the formation of detergent-resistant microdomains. In the present study, we evaluated the functional role of cholesterol and lipid rafts for entry of hepatitis B viruses into hepatocytes. We show that the duck hepatitis B virus (DHBV) attaches predominantly to detergent-soluble domains on the plasma membrane. Cholesterol depletion from host membranes and thus disruption of rafts does not affect DHBV infection. In contrast, depletion of cholesterol from the envelope of both DHBV and human HBV strongly reduces virus infectivity. Cholesterol depletion increases the density of viral particles and leads to changes in the ultrastructural appearance of the virus envelope. However, the dual topology of the viral envelope protein L is not significantly impaired. Infectivity and density of viral particles are partially restored upon cholesterol replenishment. Binding and entry of cholesterol-deficient DHBV into hepatocytes are not significantly impaired, in contrast to their release from endosomes. We therefore conclude that viral but not host cholesterol is required for endosomal escape of DHBV.

scholarly journals Protective Efficacy of DNA Vaccines against Duck Hepatitis B Virus Infection

1998 ◽  
Vol 72 (1) ◽  
pp. 84-94 ◽  
Author(s):  
M. Triyatni ◽  
A. R. Jilbert ◽  
M. Qiao ◽  
D. S. Miller ◽  
C. J. Burrell
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Virus Replication ◽  
Dna Vaccines ◽  
Protective Efficacy ◽  
Virus Infectivity ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus ◽  
S Proteins

ABSTRACT The efficacy of DNA vaccines encoding the duck hepatitis B virus (DHBV) pre-S/S and S proteins were tested in Pekin ducks. Plasmid pcDNA I/Amp DNA containing the DHBV pre-S/S or S genes was injected intramuscularly three times, at 3-week intervals. All pre-S/S and S-vaccinated ducks developed total anti-DHBs and specific anti-S antibodies with similar titers reaching 1/10,000 to 1/50,000 and 1/2,500 to 1/4,000, respectively, after the third vaccination. However, following virus challenge, significant differences in the rate of virus removal from the bloodstream and the presence of virus replication in the liver were found between the groups. In three of four S-vaccinated ducks, 90% of the inoculum was removed between <5 and 15 min postchallenge (p.c.) and no virus replication was detected in the liver at 4 days p.c. In contrast, in all four pre-S/S-vaccinated ducks, 90% of the inoculum was removed between 60 and 90 min p.c. and DHBsAg was detected in 10 to 40% of hepatocytes. Anti-S serum abolished virus infectivity when preincubated with DHBV before inoculation into 1-day-old ducklings and primary duck hepatocyte cultures, while anti-pre-S/S serum showed very limited capacity to neutralize virus infectivity in these two systems. Thus, although both DNA vaccines induced high titers of anti-DHBs antibodies, anti-S antibodies induced by the S-DNA construct were highly effective in neutralizing virus infectivity while similar levels of anti-S induced by the pre-S/S-DNA construct conferred only very limited protection. This phenomenon requires further clarification, particularly in light of the development of newer HBV vaccines containing pre-S proteins and a possible discrepancy between anti-HBs titers and protective efficacy.

scholarly journals Residues Critical for Duck Hepatitis B Virus Neutralization Are Involved in Host Cell Interaction

1999 ◽  
Vol 73 (4) ◽  
pp. 2569-2575 ◽  
Author(s):  
Claire Sunyach ◽  
Christine Rollier ◽  
Magdalena Robaczewska ◽  
Christelle Borel ◽  
Luc Barraud ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Host Cell ◽  
Single Point ◽  
Virus Neutralization ◽  
Virus Infectivity ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus

ABSTRACT To date, no detailed analysis of the neutralization properties of duck hepatitis B virus (DHBV) has been reported, and it is not clear whether any of the known neutralization epitopes correspond to the viral receptor binding site or to sequences involved in the cell entry pathway. We demonstrate here that antibodies directed against two overlapping peptides (amino acids 83 to 97 and 93 to 107), covering the sequences of most DHBV pre-S neutralizing epitopes, both inhibit virus binding to primary duck hepatocytes and neutralize virus infectivity. An extensive mutagenesis of the motif 88WTP90, which is the shortest sequence of the epitope recognized by the virus-neutralizing monoclonal antibody (MAb) 900 was performed in order to define the amino acids involved in these interactions. Single point mutations within this epitope affected neither virus replication nor infectivity but abolished virus neutralization by MAb 900 completely. Interestingly, mutants with two and three consecutive residue replacements (SIP and SIH) within this epitope retained replication competence but were no longer infectious. The loss of infectivity of SIH and SIP mutant particles was associated with significantly reduced binding to primary duck hepatocytes and could be rescued bytrans complementation with wild-type pre-S protein. Taken together, these results indicate that each amino acid of the DHBV pre-S sequence 88WTP90 is critical for recognition by the neutralizing MAb 900 and that replacement of the first two or all three residues strongly reduces virus interaction with hepatocytes and abrogates infectivity. These data imply that the motif88WTP90 contains key residues which are critical for interaction with both the neutralizing MAb and the host cell.

scholarly journals Conditional Replication of Duck Hepatitis B Virus in Hepatoma Cells

2003 ◽  
Vol 77 (3) ◽  
pp. 1885-1893 ◽  
Author(s):  
Ju-Tao Guo ◽  
Melissa Pryce ◽  
Xingtai Wang ◽  
M. Inmaculada Barrasa ◽  
Jianming Hu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Biochemical Analysis ◽  
Duck Hepatitis B Virus ◽  
Circular Dna ◽  
Duck Hepatitis ◽  
Viral Particles ◽  
B Virus ◽  
Host Cell Interactions ◽  
The Stability

ABSTRACT To facilitate investigations of replication and host cell interactions in the hepadnavirus system, we have developed cell lines permitting the conditional replication of duck hepatitis B virus (DHBV). With the help of this system, we devised conditions for core particle isolation that preserve replicase activity, which was not found in previous preparations. Investigations of the stability of viral DNA intermediates indicated that both encapsidated DNA and covalently closed circular DNA (cccDNA) were turned over independently of cell division. Moreover, we showed that alpha interferon reduced the accumulation of RNA-containing viral particles. The availability of a synchronized replication system will permit the biochemical analysis of individual steps of the viral replication cycle, including the mechanism and regulation of cccDNA formation.

Integrated structures of duck hepatitis B virus DNA in hepatocellular carcinoma.

1988 ◽  
Vol 62 (3) ◽  
pp. 861-865 ◽  
Author(s):  
F Imazeki ◽  
K Yaginuma ◽  
M Omata ◽  
K Okuda ◽  
M Kobayashi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Duck Hepatitis B Virus ◽  
Hepatitis B Virus Dna ◽  
Duck Hepatitis ◽  
B Virus ◽  
Integrated Structures

Fine Mapping of Neutralization Epitopes on Duck Hepatitis B Virus (DHBV) pre-S Protein Using Monoclonal Antibodies and Overlapping Peptides

Virology ◽  
1993 ◽  
Vol 192 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Sylvie Chassot ◽  
Véronique Lambert ◽  
Alan Kay ◽  
Catherine Godinot ◽  
Bernard Roux ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Fine Mapping ◽  
Duck Hepatitis B Virus ◽  
S Protein ◽  
Duck Hepatitis ◽  
B Virus

Duck hepatitis B virus: Cloning and subcloning of the viral genome

1989 ◽  
Vol 270 (3) ◽  
pp. 424-433
Author(s):  
Konrad Oexle ◽  
Hubert E. Blum ◽  
Eike Walter ◽  
Wolf-Bernhard Offensperger ◽  
Silke Offensperger ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Genome ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus

scholarly journals Duck hepatitis B virus: a model to assess efficacy of disinfectants against hepadnavirus infectivity

1991 ◽  
Vol 106 (3) ◽  
pp. 435-443 ◽  
Author(s):  
S. M. Murray ◽  
J. S. Freiman ◽  
K. Vickery ◽  
D. Lim ◽  
Y. E. Cossart ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Room Temperature ◽  
Virus Titre ◽  
Experimental Protocol ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus ◽  
Undiluted Serum ◽  
Sterile Filter

SUMMARYThe efficacy of three proprietary glutaraldehyde disinfectants and their component bases was assessed using the duck hepatitis B virus (DHBV) model. Inactivation of infectivity of undiluted serum containing 106·8ID50/ml DHBV was assessed after a mixture with an equal volume of disinfectant had stood at room temperature for 10 min. A dried spill of infectious serum was simulated using sterile filter paper disks, saturated with serum containing DHBV, dried and then exposed to test disinfectant for 10 min. Residual infectivity, and hence the reduction in virus titre, was determined by inoculation of dilutions of the treated samples into 1-day-old ducklings. A greater than 3 log10reduction in virus titre could be demonstrated for the disinfectants as well as for some of their component bases. Disinfectant activity varied according to the method of viral presentation but a reduction of exposure time from 10 to 2·5 min did not diminish activity. The experimental protocol permits a comparative and quantitative assessment of the efficacy of both established and new disinfectants.

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