scholarly journals Combinations of Adefovir with Nucleoside Analogs Produce Additive Antiviral Effects against Hepatitis B Virus In Vitro

2004 ◽  
Vol 48 (10) ◽  
pp. 3702-3710 ◽  
Author(s):  
William E. Delaney ◽  
Huiling Yang ◽  
Michael D. Miller ◽  
Craig S. Gibbs ◽  
Shelly Xiong
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Adefovir Dipivoxil ◽  
Nucleoside Analogs ◽  
Stable Cell Line ◽  
Wild Type ◽  
Nucleotide Analog ◽  
Antiviral Effects ◽  
B Virus

ABSTRACT Combination therapies may be required for long-term management of some patients chronically infected with hepatitis B virus (HBV). Adefovir is a nucleotide analog that has similar activity against wild-type and lamivudine-resistant HBV. In contrast to lamivudine, clinical resistance to the prodrug adefovir dipivoxil emerges infrequently. Based on its clinical efficacy and low frequency of resistance, adefovir dipivoxil may form an important component of combination regimens. We therefore investigated the in vitro antiviral efficacy of combinations of adefovir with other nucleoside analogs (lamivudine, entecavir, emtricitabine [FTC],and telbivudine [L-dT]) and the nucleotide analog tenofovir. Using a novel stable cell line that expresses high levels of wild-type HBV, we assayed the antiviral activity of each drug alone and in combination with adefovir. All two-drug combinations resulted in greater antiviral effects than treatments with single agents and could be characterized as additive by the Bliss independence model. Analysis using the Loewe additivity model indicated that adefovir exerted additive antiviral effects when combined with lamivudine, FTC, or L-dT and moderately synergistic effects when combined with entecavir or tenofovir. There was no evidence of cytotoxicity with any of the drugs when used alone or in combination at the tested doses.

scholarly journals IL-33 Inhibits Hepatitis B Virus through Its Receptor ST2 in Hydrodynamic HBV Mouse Model

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiuzhu Gao ◽  
Xiumei Chi ◽  
Xiaomei Wang ◽  
Ruihong Wu ◽  
Hongqin Xu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Mouse Model ◽  
Hepg2 Cells ◽  
Hbv Dna ◽  
Dependent Manner ◽  
Wild Type ◽  
Antiviral Effects ◽  
B Virus

Interleukin-33 has been demonstrated to be associated with liver damage. However, its potential value in hepatitis B virus (HBV) infection remains unknown. This study was designed to investigate the role of IL-33 in hydrodynamic HBV mouse model. Different doses of IL-33 were used to treat HBV wild-type, ST2 knockout, CD8+ T depletion, NK depletion C57BL/6 mice and C.B-17 SCID and nod SCID mouse, respectively. The concentrations of HBV DNA, HBsAg, HBeAg, and molecules related to liver function were detected in the collected serum at different time points from model mice. Intrahepatic HBcAg was visualized by immunohistochemical staining of liver tissues. In vitro, hepG2 cells were transfected with pAAV-HBV 1.2, then treated with IL-33. The results showed that IL-33 significantly reduced HBV DNA and HBsAg in a dose-dependent manner in HBV wild-type mice. However, in the IL-33 specific receptor ST2 knockout mice, their antiviral effects could not be exerted. Through immunodeficient animal models and in vivo immune cell depletion mouse model, we found that IL-33 could not play antiviral effects without NK cells. Moreover, IL-33 could reduce the levels of HBsAg and HBeAg in the supernatant of HBV-transfected hepG2 cells in vitro. Our study revealed that IL-33 could inhibit HBV through ST2 receptor in the HBV mouse model, and this effect can be impaired without NK cell. Additionally, IL-33 had the direct anti-HBV effect in vitro, indicating that IL-33 could be a potent inducer of HBV clearance and a promising drug candidate.

scholarly journals Phosphorothioate Di- and Trinucleotides as a Novel Class of Anti-Hepatitis B Virus Agents

2004 ◽  
Vol 48 (6) ◽  
pp. 2199-2205 ◽  
Author(s):  
Radhakrishnan P. Iyer ◽  
Yi Jin ◽  
Arlene Roland ◽  
John D. Morrey ◽  
Samir Mounir ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nucleoside Analogs ◽  
Hbv Dna ◽  
Parallel Synthesis ◽  
Hbv Replication ◽  
Long Term Treatment ◽  
B Virus ◽  
Dna Strand

ABSTRACT Several nucleoside analogs are under clinical development for use against hepatitis B virus (HBV). Lamivudine (3TC), a nucleoside analog, and adefovir dipivoxil (ADV), an acyclonucleotide analog, are clinically approved. However, long-term treatment can induce viral resistance, and following the cessation of therapy, viral rebound is frequently observed. There continues to be a need for new antiviral agents with novel mechanisms of action. A library of more than 600 di- and trinucleotide compounds synthesized by parallel synthesis using a combinatorial strategy was screened for potential inhibitors of HBV replication using the chronically HBV-producing cell line 2.2.15. Through an iterative process of synthesis, lead optimization, and screening, three analogs were identified as potent inhibitors of HBV replication: dinucleotides ORI-7246 (drug concentration at which a 10-fold reduction of HBV DNA was observed [EC90], 1.4 μM) and ORI-9020 (EC90, 1.2 μM) and trinucleotide ORI-7170 (EC90, 7.2 μM). These analogs inhibited the replication of both strands of HBV DNA. No suppression of HBV protein synthesis or intracellular core particle formation by these analogs was observed. No inhibition of HBV DNA strand elongation by the analogs or their 5′-triphosphate versions was apparent in in vitro polymerase assays. Although the exact mechanism of action is not yet identified, present data are consistent with an inhibition of the HBV reverse transcriptase-directed priming step prior to elongation of the first viral DNA strand. In transient-transfection assays, these analogs inhibited the replication of 3TC-resistant HBV. Synergistic interactions in combination treatments between the analogs and either 3TC or ADV were observed. These compounds represent a novel class of anti-HBV molecules and warrant further investigation as potential therapeutic agents.

scholarly journals Novel Hepatitis B Virus Capsid Assembly Modulator Induces Potent Antiviral Responses In Vitro and in Humanized Mice

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Franck Amblard ◽  
Sebastien Boucle ◽  
Leda Bassit ◽  
Bryan Cox ◽  
Ozkan Sari ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nucleoside Analogs ◽  
Humanized Mouse Model ◽  
Single Digit ◽  
Viral Loads ◽  
Antiviral Responses ◽  
B Virus

ABSTRACT Hepatitis B virus (HBV) affects an estimated 250 million chronic carriers worldwide. Though several vaccines exist, they are ineffective for those already infected. HBV persists due to the formation of covalently closed circular DNA (cccDNA)—the viral minichromosome—in the nucleus of hepatocytes. Current nucleoside analogs and interferon therapies rarely clear cccDNA, requiring lifelong treatment. Our group identified GLP-26, a novel glyoxamide derivative that alters HBV nucleocapsid assembly and prevents viral DNA replication. GLP-26 exhibited single-digit nanomolar anti-HBV activity, inhibition of HBV e antigen (HBeAg) secretion, and reduced cccDNA amplification, in addition to showing a promising preclinical profile. Strikingly, long term combination treatment with entecavir in a humanized mouse model induced a decrease in viral loads and viral antigens that was sustained for up to 12 weeks after treatment cessation.

Hepatitis B virus genotype C encoding resistance mutations that emerge during adefovir dipivoxil therapy: in vitro replication phenotype

2012 ◽  
Vol 7 (2) ◽  
pp. 443-450 ◽  
Author(s):  
Wenpeng Li ◽  
Nadia Warner ◽  
Vitina Sozzi ◽  
Lilly Yuen ◽  
Danni Colledge ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Adefovir Dipivoxil ◽  
Resistance Mutations ◽  
Virus Genotype ◽  
In Vitro Replication ◽  
B Virus ◽  
Genotype C

scholarly journals Efficacies of Entecavir against Lamivudine-Resistant Hepatitis B Virus Replication and Recombinant Polymerases In Vitro

2002 ◽  
Vol 46 (8) ◽  
pp. 2525-2532 ◽  
Author(s):  
S. Levine ◽  
D. Hernandez ◽  
G. Yamanaka ◽  
S. Zhang ◽  
R. Rose ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cross Resistance ◽  
Wild Type ◽  
Resistance Mutations ◽  
Hbv Replication ◽  
B Virus ◽  
Inhibition Studies

ABSTRACT Entecavir (ETV) is a potent and selective inhibitor of hepatitis B virus (HBV) replication in vitro and in vivo that is currently in clinical trials for the treatment of chronic HBV infections. A major limitation of the current HBV antiviral therapy, lamivudine (3TC), is the emergence of drug-resistant HBV in a majority of treated patients due to specific mutations in the nucleotide binding site of HBV DNA polymerase (HBV Pol). To determine the effects of 3TC resistance mutations on inhibition by ETV triphosphate (ETV-TP), a series of in vitro studies were performed. The inhibition of wild-type and 3TC-resistant HBV Pol by ETV-TP was measured using recombinant HBV nucleocapsids, and compared to that of 3TC-TP. These enzyme inhibition studies demonstrated that ETV-TP is a highly potent inhibitor of wild-type HBV Pol and is 100- to 300-fold more potent than 3TC-TP against 3TC-resistant HBV Pol. Cell culture assays were used to gauge the potential for antiviral cross-resistance of 3TC-resistant mutants to ETV. Results demonstrated that ETV inhibited the replication of 3TC-resistant HBV, but 20- to 30-fold higher concentrations were required. To gain further perspective regarding the potential therapeutic use of ETV, its phosphorylation was examined in hepatoma cells treated with extracellular concentrations representative of drug levels in plasma in ETV-treated patients. At these concentrations, intracellular ETV-TP accumulated to levels expected to inhibit the enzyme activity of both wild-type and 3TC-resistant HBV Pol. These findings are predictive of potent antiviral activity of ETV against both wild-type and 3TC-resistant HBV.

The M539V Polymerase Variant of Human Hepatitis B Virus Demonstrates Resistance to 2′-Deoxy-3′-Thiacytidine and a Reduced Ability to Synthesize Viral DNA

1998 ◽  
Vol 42 (8) ◽  
pp. 2128-2131 ◽  
Author(s):  
Stephanie K. Ladner ◽  
Thomas J. Miller ◽  
Robert W. King
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Infection ◽  
Wild Type ◽  
Viral Dna ◽  
Transfected Cells ◽  
Transplant Patients ◽  
Antiviral Effects ◽  
Chronic Hepatitis B Virus ◽  
B Virus

ABSTRACT The cytosine analog 2′-deoxy-3′-thiacytidine (3TC) has been shown to be an effective treatment for chronic hepatitis B virus (HBV) infection. However, several liver transplant patients who were undergoing treatment with 3TC for HBV infection experienced a breakthrough of virus while on 3TC. The predominant virus found in these patients’ sera contained either a valine or isoleucine for the methionine in the highly conserved YMDD nucleotide binding site in the HBV polymerase. To determine the biological relevance of the Met-to-Val substitution, we mutated a plasmid that contained a cDNA copy of the HBV pregenomic RNA such that when virus replication occurred during transient transfection of HepG2 cells, an M539V polymerase variant was produced. We found that in transiently transfected cells, this variant was approximately 330-fold less sensitive to the antiviral effects of 3TC and produced 7-fold less viral DNA than the wild type.

scholarly journals Identification of BMS-200475 as a potent and selective inhibitor of hepatitis B virus.

1997 ◽  
Vol 41 (7) ◽  
pp. 1444-1448 ◽  
Author(s):  
S F Innaimo ◽  
M Seifer ◽  
G S Bisacchi ◽  
D N Standring ◽  
R Zahler ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Line ◽  
Nucleoside Analogs ◽  
Hbv Replication ◽  
Mitochondrial Dna Content ◽  
B Virus ◽  
Antiviral Activities ◽  
Replicative Intermediates

BMS-200475 is a novel carbocyclic 2'-deoxyguanosine analog found to possess potent and selective anti-hepatitis B virus (anti-HBV) activity. BMS-200475 is distinguished from guanosine by replacement of the natural furanose oxygen on the sugar moiety with an exo carbon-carbon double bond. In the HepG2 stably transfected cell line 2.2.15, BMS-200475 had a 50% effective concentration (EC50) of 3.75 nM against HBV, as determined by analysis of secreted HBV DNA. Structurally related compounds with adenine, iodouracil, or thymine base substitutions were significantly less potent or were inactive. Direct comparison of the antiviral activities of BMS-200475 with those of a variety of other nucleoside analogs, including lamivudine (EC50 = 116.26 nM), demonstrated the clearly superior in vitro potency of BMS-200475 in 2.2.15 cells. Intracellular HBV replicative intermediates were uniformly reduced when cells were treated with BMS-200475, but rebounded after treatment was terminated. The concentration of BMS-200475 causing 50% cytotoxicity in 2.2.15 cell cultures was 30 microM, approximately 8,000-fold greater than the concentration required to inhibit HBV replication in the same cell line. Treatment with BMS-200475 resulted in no apparent inhibitory effects on mitochondrial DNA content.

scholarly journals Characterization of Novel Human Hepatoma Cell Lines with Stable Hepatitis B Virus Secretion for Evaluating New Compounds against Lamivudine- and Penciclovir-Resistant Virus

2000 ◽  
Vol 44 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Lei Fu ◽  
Yung-Chi Cheng
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Lines ◽  
Hepatoma Cell ◽  
Nucleoside Analogs ◽  
Cross Resistance ◽  
Resistant Virus ◽  
Wild Type ◽  
Human Hepatoma Cell ◽  
B Virus

ABSTRACT l-Nucleoside analogs are new therapeutic agents for treatment of chronic hepatitis B. However, their clinical application was limited by the emergence of viral resistance. It is important to develop a new system to evaluate drug cross-resistance and to test new agents that may overcome resistant virus. In this report, three cell lines HepG2-WT10, HepG2-SM1, and HepG2-DM2 are presented; these cell lines were established by transfection of HepG2 cells with unique fully functional 1.1× hepatitis B virus (HBV) genomes: wild-type HBV-adr and its L526M and L526MM550V variants, respectively. We have demonstrated that these genomes have different susceptibilities to lamivudine [l(−)SddC] and penciclovir (PCV). By examining HBV RNA transcription, antigen expression, progeny DNA replication, and viral susceptibilities to l(−)SddC, PCV, and other nucleoside analogs, it is concluded that the cell lines are able to stably producel(−)SddC- and PCV-sensitive and -resistant HBV virions. In addition, the relative susceptibilities of the wild-type and mutant HBV produced from the stably transfected cell lines to several anti-HBV nucleoside analogs were also examined and found to be about the same as those found by using a transient infection system. PMEA [9-(2-phosphonylmethoxytehyl)-adenine] and QYL685 are able to suppress l(−)SddC- and PCV-resistant HBV. In conclusion, this cell culture system is a novel and useful tool for evaluating anti-HBV compounds and biologics.

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