scholarly journals Enrichment of a Precore-Minus Mutant of Duck Hepatitis B Virus in Experimental Mixed Infections

1999 ◽  
Vol 73 (5) ◽  
pp. 3616-3622 ◽  
Author(s):  
Yong-Yuan Zhang ◽  
Jesse Summers
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Mutant Virus ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus ◽  
Precore Mutant

ABSTRACT A precore-deficient mutant of duck hepatitis B virus (DHBV) produced by site-directed mutagenesis was tested for its ability to compete with wild-type virus in a mixed infection of 3-day-old ducklings. The mutation was shown to produce a cis-acting defect, resulting in a replication rate that was about one-half that of wild-type virus. Accordingly, wild-type virus was rapidly selected during the spread of infection. During the chronic phase of the infection, however, two selection patterns were seen. In 4 of 10 ducks, the wild-type virus slowly replaced the precore mutant. In another four ducks, the precore mutant virus slowly replaced the wild-type virus. In the remaining two ducklings, ratios of wild-type and precore mutant virus fluctuated, with wild-type virus slowly predominating. The replacement of wild-type virus was not due to the emergence of a rapidly replicating variant of the precore mutant, since genomes cloned from the infected ducks retained their original replication defect. Replacement of wild-type virus, however, correlated with elevated anti-core antibody titers, which continued to increase with time. The selection of a precore-negative strain of DHBV may be analogous to the selection for precore mutants of HBV during chronic hepatitis in humans.

scholarly journals Cellular Receptor Traffic Is Essential for Productive Duck Hepatitis B Virus Infection

2000 ◽  
Vol 74 (5) ◽  
pp. 2203-2209 ◽  
Author(s):  
Klaus M. Breiner ◽  
Heinz Schaller
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Entry ◽  
Transmembrane Protein ◽  
Cellular Receptor ◽  
Receptor Function ◽  
Wild Type ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus

ABSTRACT We have investigated the mechanism of duck hepatitis B virus (DHBV) entry into susceptible primary duck hepatocytes (PDHs), using mutants of carboxypeptidase D (gp180), a transmembrane protein shown to act as the primary cellular receptor for avian hepatitis B virus uptake. The variant proteins were abundantly produced from recombinant adenoviruses and tested for the potential to functionally outcompete the endogenous wild-type receptor. Overexpression of wild-type gp180 significantly enhanced the efficiency of DHBV infection in PDHs but did not affect ongoing DHBV replication, an observation further supporting gp180 receptor function. A gp180 mutant deficient for endocytosis abolished DHBV infection, indicating endocytosis to be the route of hepadnaviral entry. With further gp180 variants, carrying mutations in the cytoplasmic domain and characterized by an accelerated turnover, the ability of gp180 to function as a DHBV receptor was found to depend on a wild-type-like sorting phenotype which largely avoids transport toward the endolysosomal compartment. Based on these data, we propose a model in which a distinct intracellular DHBV traffic to the endosome, but not beyond, is a prerequisite for completion of viral entry, i.e., for fusion and capsid release. Furthermore, the deletion of the two enzymatically active carboxypeptidase domains of gp180 did not lead to a loss of receptor function.

Generation of duck hepatitis B virus polymerase mutants through site-directed mutagenesis which demonstrate resistance to lamivudine [(--)-beta-L-2', 3'-dideoxy-3'-thiacytidine] in vitro.

1996 ◽  
Vol 40 (8) ◽  
pp. 1957-1960 ◽  
Author(s):  
K P Fischer ◽  
D L Tyrrell
Keyword(s):  
Amino Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Amino Acid Change ◽  
Single Amino Acid ◽  
Wild Type Virus ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
Single Amino Acid Change ◽  
B Virus

Hepatitis B virus replication is very sensitive to lamivudine. A single amino acid change in human immunodeficiency virus reverse transcriptase is responsible for high-level resistance to this compound. Duck hepatitis B virus mutants were created bearing the analogous amino acid change in the duck hepatitis B virus polymerase. Viral DNA production was reduced 92% for the wild-type virus at 2 micrograms of lamivudine per ml, while the mutants required 40 micrograms of lamivudine per ml to inhibit replication by greater than 80%.

scholarly journals Presence of Replicating Virus in Recombinant Hepadnavirus Stocks Results from Recombination and Can Be Eliminated by the Use of a Packaging Cell Line

2003 ◽  
Vol 77 (5) ◽  
pp. 2873-2881 ◽  
Author(s):  
Uta Klöcker ◽  
Heike Oberwinkler ◽  
Timo Kürschner ◽  
Ulrike Protzer
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Wild Type Virus ◽  
Recombinant Hepatitis ◽  
Type Virus ◽  
Wild Type ◽  
Viral Genomes ◽  
B Virus ◽  
Viral Sequences

ABSTRACT Mutant hepatitis B viruses are useful tools to study the viral life cycle and viral pathogenesis. Furthermore, recombinant hepatitis B viruses are candidate vectors for liver-directed gene therapy. Because wild-type viruses present in recombinant or mutant virus stocks may falsify experimental results and are detrimental for a viral vector, we investigated whether and to what extent wild-type virus is present in recombinant virus stocks and where it originates from. We took advantage of the duck model of hepatitis B virus infection which allows very sensitive detection of replication-competent viruses by infection of primary duck hepatocytes or of ducklings in vivo. Recombinant hepatitis B virus stocks contained significant amounts of wild-type viruses, which were most probably generated by homologous recombination between plasmids containing homologous viral sequences. In addition, replication-competent viral genomes were reconstituted from plasmids which contained replication-deficient but redundant viral sequences. Using a stable cell line for packaging of deficient viral genomes, no wild-type virus was detected, neither by infection of primary hepatocytes nor in vivo.

A novel hepatitis B virus mutant coexisting with wild type virus in a carrier with negative HBsAg yet positive HBeAg and anti-HBs

2009 ◽  
Vol 46 (4) ◽  
pp. 363-366 ◽  
Author(s):  
Yi-Hua Zhou ◽  
Jianxin Zhou ◽  
Lei Li ◽  
Yongchun Bi ◽  
Yong Liu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
B Virus ◽  
Virus Mutant ◽  
Positive Hbeag

scholarly journals Double-Stranded Linear Duck Hepatitis B Virus (DHBV) Stably Integrates at a Higher Frequency than Wild-Type DHBV in LMH Chicken Hepatoma Cells

1999 ◽  
Vol 73 (2) ◽  
pp. 1492-1502 ◽  
Author(s):  
Shih S. Gong ◽  
Anne D. Jensen ◽  
C. J. Chang ◽  
Charles E. Rogler
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatoma Cell Line ◽  
Wild Type ◽  
Chromosomal Dna ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus ◽  
R Region ◽  
Open Circular

ABSTRACT Integration of hepadnavirus DNAs into host chromosomes can have oncogenic consequences. Analysis of host-viral DNA junctions of DHBV identified the terminally duplicated r region of the viral genome as a hotspot for integration. Since the r region is present on the 5′ and 3′ ends of double-stranded linear (DSL) hepadnavirus DNAs, these molecules have been implicated as integration precursors. We have produced a LMH chicken hepatoma cell line (LMH 66-1 DSL) which replicates exclusively DSL duck hepatitis B virus (DHBV) DNA. To test whether linear DHBV DNAs integrate more frequently than the wild type open circular DHBV DNAs, we have characterized the integration frequency in LMH 66-1 DSL cells by using a subcloning approach. This approach revealed that 83% of the LMH 66-1 DSL subclones contained new integrations, compared to only 16% of subclones from LMH-D2 cells replicating wild-type open circular DHBV DNA. Also, a higher percentage of the LMH 66-1 DSL subclones contained two or more new integrations. Mathematical analysis suggests that the DSL DHBV DNAs integrated stably once every three generations during subcloning whereas wild-type DHBV integrated only once every four to five generations. Cloning and sequencing of new integrations confirmed the r region as a preferred integration site for linear DHBV DNA molecules. One DHBV integrant was associated with a small deletion of chromosomal DNA, and another DHBV integrant occurred in a telomeric repeat sequence.

scholarly journals Competitionin Vivobetween a Cytopathic Variant and a Wild-Type Duck Hepatitis B Virus

Virology ◽  
1998 ◽  
Vol 251 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Raymond J. Lenhoff ◽  
Carolyn A. Luscombe ◽  
Jesse Summers
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Wild Type ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus
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