scholarly journals CRISPR/Cas9 delivery by NIR-responsive biomimetic nanoparticles for targeted HBV therapy

2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Dan Wang ◽  
Ling Chen ◽  
Chengbi Li ◽  
Quanxin Long ◽  
Qing Yang ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
High Efficiency ◽  
Efficient Treatment ◽  
Hbv Replication ◽  
Hbv Cccdna ◽  
Potential System ◽  
B Virus ◽  
Biomimetic Nanoparticles ◽  
Infected Cells

Abstract Background Currently, there are no curative drugs for hepatitis B virus (HBV). Complete elimination of HBV covalently closed circular DNA (cccDNA) is key to the complete cure of hepatitis B virus infection. The CRISPR/Cas9 system can directly destroy HBV cccDNA. However, a CRISPR/Cas9 delivery system with low immunogenicity and high efficiency has not yet been established. Moreover, effective implementation of precise remote spatiotemporal operations in CRISPR/Cas9 is a major limitation. Results In this work, we designed NIR-responsive biomimetic nanoparticles (UCNPs-Cas9@CM), which could effectively deliver Cas9 RNP to achieve effective genome editing for HBV therapy. HBsAg, HBeAg, HBV pgRNA and HBV DNA along with cccDNA in HBV-infected cells were found to be inhibited. These findings were confirmed in HBV-Tg mice, which did not exhibit significant cytotoxicity and minimal off-target DNA damage. Conclusions The UCNPs-based biomimetic nanoplatforms achieved the inhibition of HBV replication via CRISPR therapy and it is a potential system for efficient treatment of human HBV diseases. Graphical Abstract

scholarly journals Replenishment of Hepatitis B Virus cccDNA Pool Is Restricted by Baseline Expression of Host Restriction Factors In Vitro

2019 ◽  
Vol 7 (11) ◽  
pp. 533 ◽  
Author(s):  
Sergey Brezgin ◽  
Anastasiia Kostyusheva ◽  
Ekaterina Bayurova ◽  
Ilya Gordeychuk ◽  
Maria Isaguliants ◽  
...  
Keyword(s):  
Dna Damage ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Real Time ◽  
Real Time Pcr ◽  
Hbv Replication ◽  
Hbv Cccdna ◽  
B Virus ◽  
Infected Cells ◽  
Cell Cycling

Background: Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is the major cause of viral persistence in patients with chronic HBV infection. Understanding the mechanisms underlying stability and persistence of HBV cccDNA in hepatocytes is critical for developing novel therapeutics and managing chronic hepatitis B. In this study, we observed an unexpected increase in HBV cccDNA levels upon suppression of transcription by de novo DNA methyltransferase DNMT3A and uncovered additional mechanisms potentially involved in HBV cccDNA maintenance. Methods: HBV-expressing cell lines were transfected with a DNMT3A-expressing plasmid. Real-time PCR and HBsAg assays were used to assess the HBV replication rate. Cell cycling was analyzed by fluorescent cell sorting. CRISPR/Cas9 was utilized to abrogate expression of APOBEC3A and APOBEC3B. Alterations in the expression of target genes were measured by real-time PCR. Results: Similar to previous studies, HBV replication induced DNMT3A expression, which in turn, led to reduced HBV transcription but elevated HBV cccDNA levels (4- to 6-fold increase). Increased levels of HBV cccDNA were not related to cell cycling, as DNMT3A accelerated proliferation of infected cells and could not contribute to HBV cccDNA expansion by arresting cells in a quiescent state. At the same time, DNMT3A suppressed transcription of innate immunity factors including cytidine deaminases APOBEC3A and APOBEC3B. CRISPR/Cas9-mediated silencing of APOBEC3A and APOBEC3B transcription had minor effects on HBV transcription, but significantly increased HBV cccDNA levels, similar to DNMT3A. In an attempt to further analyze the detrimental effects of HBV and DNMT3A on infected cells, we visualized γ-H2AX foci and demonstrated that HBV inflicts and DNMT3A aggravates DNA damage, possibly by downregulating DNA damage response factors. Additionally, suppression of HBV replication by DNMT3A may be related to reduced ATM/ATR expression. Conclusion: Formation and maintenance of HBV cccDNA pools may be partially suppressed by the baseline expression of host inhibitory factors including APOBEC3A and APOBEC3B. HBV inflicts DNA damage both directly and by inducing DNMT3A expression.

scholarly journals 3-Hydroxypyrimidine-2,4-Diones as Novel Hepatitis B Virus Antivirals Targeting the Viral Ribonuclease H

2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Andrew D. Huber ◽  
Eleftherios Michailidis ◽  
Jing Tang ◽  
Maritza N. Puray-Chavez ◽  
Maria Boftsi ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Antiviral Activity ◽  
Essential Role ◽  
Rnase H ◽  
Ribonuclease H ◽  
Hbv Replication ◽  
B Virus ◽  
Infected Cells ◽  
Micromolar Range

ABSTRACT Hepatitis B virus (HBV) RNase H (RNH) is an appealing therapeutic target due to its essential role in viral replication. RNH inhibitors (RNHIs) could help to more effectively control HBV infections. Here, we report 3-hydroxypyrimidine-2,4-diones as novel HBV RNHIs with antiviral activity. We synthesized and tested 52 analogs and found 4 that inhibit HBV RNH activity in infected cells. Importantly, 2 of these compounds inhibited HBV replication in the low micromolar range.

scholarly journals The cooperative complex of Argonaute-2/MicroRNA-146a regulates Hepatitis B Virus replication through FEN1

2020 ◽  
Author(s):  
min ji ◽  
Xiaoping Mei ◽  
Xunming Jing ◽  
Xu Xu ◽  
Xing Chen ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Expression Level ◽  
Control Group ◽  
Transcriptional Level ◽  
Downstream Target ◽  
Hbv Replication ◽  
Hbv Cccdna ◽  
B Virus

Abstract Background: The regulatory of HBV replication is still unclear. FEN1 can repair HBV rcDNA to HBV cccDNA and promote HBV DNA replication. However, its specific regulatory detail remains unclear. MicroRNA regulates gene expression at post-transcriptional level. Especially, miR-146a, it plays an important role that is closely related to regulation of HBV replication. Based on above, we hypothesize that miR-146a may be regulate HBV cccDNA formation through FEN1. So, we will investigate the effect of miR-146a on the replication of hepatitis B virus and its molecular mechanism. Results: We found that level of miR-146a was significantly up-regulated in HepG2.2.15 cells (11.755±0.069) than that in HepG2 (1.000±0.038) (P<0.05). Furthermore, HBV-DNA copies and FEN1 were significantly increased and decreased, respectively, in HepG2.2.15 cells transfected with miR-146a mimic and inhibitor for 48h,[(3.215±0.001); (2.623±0.083)] compared with the control group (2.813±0.015) (P<0.05),. After transfection FEN1 plasmid, HBV-DNA Copies (5.712±0.371) is significantly higher than the control group（2.661±0.009）(P<0.05), and the level of miR-146a（3.431±0.004）is significantly higher than the control group (1.023±0.224） (P<0.05). The expression level of IRAK1/TRAF6 are significantly lower and higher [(0.114±0.013); (0.390±0.014); (1.222±0.073); (2.145±0.271)] than the control group [(1.000±0.038); (1.007±0.119)] (P<0.05) after transfection miR-146a mimic and inhibitor into HepG2.2.15. After Ago2 siRNA, the level of miR-146a (0.105±0.002) is significantly decreased than the control group (1.000±0.041) (P<0.05) from Ago2 protein RIP. After transfection Ago2 siRNA then added into exogenous miR-146a into HepG2.2.15, The expression level of FEN1 is significantly reduced (0.485±0.100) than the control group (1.000±0.023) (P<0.05), and the HBV-DNA copies is significantly lower (3.230±0.047) than the control group (3.789±0.041) (P<0.05). Conclusion: Ago2 cooperates with miR-146a to regulate the transcription the expression level of FEN1 protein through the downstream target gene IRAK1/TRAF6, then promoting HBV replication.

In vitro Anti-Human Immunodeficiency Virus and Anti-Hepatitis B Virus Activities and Pharmacokinetic Properties of Heterodinucleoside Phosphates Containing AZT or ddC

1998 ◽  
Vol 9 (2) ◽  
pp. 117-126 ◽  
Author(s):  
PA Peghini ◽  
R Zahner ◽  
H Kuster ◽  
H Schott ◽  
RA Schwendener
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Blood Levels ◽  
Hbv Replication ◽  
B Virus ◽  
Immunodeficiency Virus ◽  
Pharmacokinetic Properties ◽  
Infected Cells

In vitro activities, against human immunodeficiency virus (HIV)- and hepatitis B virus (HBV)-infected cells, of four amphiphilic heterodinucleoside phosphates containing 3′-azido-2′,3′-dideoxythymidine (AZT) or 2′,3′-dideoxycytidine (ddC) as antiviral monomers were evaluated. The four compounds were N4-hexadecyl-2′-deoxyribocytidylyl-(3′→5′)-3′-azido-2′,3′-deoxythymidine (N4-hxddC-AZT), N4-palmitoyl-2′-deoxyribocytidylyl-(3′→5′)-3′-azido-2′,3′-deoxythymidine (N4-pamdC-AZT), N4-hexadecyl-2′-deoxycytidylyl-(3′→5′)-2′,3′-dideoxycytidine (N4-hxddC-ddC) and 2′-deoxythymidylyl-(3′→5′)-N4-palmitoyl-2′,3′-dideoxycytidine (dT-N4-pamddC). All four dimers were active against HIV, dT-N4-pamddC being the most active and least toxic. dT-N4-pamddC also exhibited strong antiviral effects against a panel of eight AZT-resistant HIV strains. The ddC-containing heterodimers incorporated in liposomes additionally inhibited HBV replication by 50–80% in HepG2 2.2.15 cells. AZT and the AZT-containing dimers were ineffective. Differences in pharmacokinetic properties between the antiviral monomers and the heterodimers were evaluated using liposomal formulations of3H-labelled AZT heterodimers as model compounds. The cellular distribution of AZT in H9 cells was predominantly cytoplasmic, whereas the amphiphilic dimers were distributed more evenly throughout the cytoplasm, nuclear membranes and microsomes. Blood levels of the heterodimers decreased at a rate two- to threefold slower than AZT and the areas-under-the-curves were five- to sevenfold higher for N4-pamdC-AZT and N4-hxddC-AZT, respectively. Compared to AZT, the peak levels of the dimers were three to four times higher in blood and five to six times higher in the liver. Analysis of blood samples showed that 34% of N4-pamdC-AZT was metabolized to AZT, whereas only 9% of N4-hxddC-AZT released AZT. Considering the antiviral potency and the favourable pharmacokinetic properties of the heterodimers, these compounds merit further exploration as antiviral drugs.

scholarly journals Apoptosis of Hepatitis B Virus-Infected Hepatocytes Prevents Release of Infectious Virus

2010 ◽  
Vol 84 (22) ◽  
pp. 11994-12001 ◽  
Author(s):  
Silke Arzberger ◽  
Marianna Hösel ◽  
Ulrike Protzer
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Inverse Correlation ◽  
Infection Model ◽  
Virus Particles ◽  
Hbv Replication ◽  
Culture Model ◽  
B Virus ◽  
A Cell ◽  
Infected Cells

ABSTRACT Apoptosis of infected cells is critically involved in antiviral defense. Apoptosis, however, may also support the release and spread of viruses. Although the elimination of infected hepatocytes is required to combat hepatitis B virus (HBV) infection, it is still unknown which consequences hepatocyte apoptosis has for the virus and whether or not it is advantageous to the virus. To study this, we designed a cell culture model consisting of both HBV-producing cell lines and primary human hepatocytes serving as an infection model. We showed that the release of mature, enveloped virions was 80% to 90% reduced 24 h after the induction of apoptosis in HBV-replicating hepatoma cells or HBV-infected hepatocytes. Importantly, HBV particles released from apoptotic hepatocytes were immature and nonenveloped and proved not to be infectious. We found an inverse correlation between the strength of an apoptotic stimulus and the infectivity of the virus particles released: the more potent the apoptotic stimulus, the higher the ratio of nonenveloped capsids to virions and the lower their infectivity. Furthermore, we demonstrated that HBV replication and, particularly, the expression of the HBx protein transcribed from the viral genome during replication do not sensitize cells to apoptosis. Our data clearly reject the hypothesis that the apoptosis of infected hepatocytes facilitates the propagation of HBV. Rather, these data indicate that HBV needs to prevent the apoptosis of its host hepatocyte to ensure the release of infectious progeny and, thus, virus spread in the liver.

scholarly journals Host Transcription Factors in Hepatitis B Virus RNA Synthesis

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 160 ◽  
Author(s):  
Kristi L. Turton ◽  
Vanessa Meier-Stephenson ◽  
Maulik D. Badmalia ◽  
Carla S. Coffin ◽  
Trushar R. Patel
Keyword(s):  
Transcription Factors ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Drug Targets ◽  
Host Protein ◽  
Hbv Replication ◽  
Hbv Cccdna ◽  
Virus Rna ◽  
B Virus ◽  
Genome Interactions

The hepatitis B virus (HBV) chronically infects over 250 million people worldwide and is one of the leading causes of liver cancer and hepatocellular carcinoma. HBV persistence is due in part to the highly stable HBV minichromosome or HBV covalently closed circular DNA (cccDNA) that resides in the nucleus. As HBV replication requires the help of host transcription factors to replicate, focusing on host protein–HBV genome interactions may reveal insights into new drug targets against cccDNA. The structural details on such complexes, however, remain poorly defined. In this review, the current literature regarding host transcription factors’ interactions with HBV cccDNA is discussed.

scholarly journals Mechanism of Hepatitis B Virus cccDNA Formation

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1463
Author(s):  
Lei Wei ◽  
Alexander Ploss
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Medical Problem ◽  
Circular Dna ◽  
Critical Step ◽  
Hbv Cccdna ◽  
Double Stranded Dna ◽  
Cellular Environment ◽  
B Virus ◽  
Comprehensive Picture

Hepatitis B virus (HBV) remains a major medical problem affecting at least 257 million chronically infected patients who are at risk of developing serious, frequently fatal liver diseases. HBV is a small, partially double-stranded DNA virus that goes through an intricate replication cycle in its native cellular environment: human hepatocytes. A critical step in the viral life-cycle is the conversion of relaxed circular DNA (rcDNA) into covalently closed circular DNA (cccDNA), the latter being the major template for HBV gene transcription. For this conversion, HBV relies on multiple host factors, as enzymes capable of catalyzing the relevant reactions are not encoded in the viral genome. Combinations of genetic and biochemical approaches have produced findings that provide a more holistic picture of the complex mechanism of HBV cccDNA formation. Here, we review some of these studies that have helped to provide a comprehensive picture of rcDNA to cccDNA conversion. Mechanistic insights into this critical step for HBV persistence hold the key for devising new therapies that will lead not only to viral suppression but to a cure.

scholarly journals Hepatitis B Core-Related Antigen as Surrogate Biomarker of Intrahepatic Hepatitis B Virus Covalently-Closed-Circular DNA in Patients with Chronic Hepatitis B: A Meta-Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 187
Author(s):  
Gian Paolo Caviglia ◽  
Angelo Armandi ◽  
Chiara Rosso ◽  
Davide Giuseppe Ribaldone ◽  
Rinaldo Pellicano ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis B Surface Antigen ◽  
Meta Analysis ◽  
Circular Dna ◽  
Non Invasive ◽  
Hbv Cccdna ◽  
B Virus ◽  
Chronic Hbv ◽  
Intrahepatic Hbv

Hepatitis B virus (HBV) covalently-closed-circular (ccc)DNA is the key molecule responsible for viral persistence within infected hepatocytes. The evaluation of HBV cccDNA is crucial for the management of patients with chronic HBV infection and for the personalization of treatment. However, the need for liver biopsy is the principal obstacle for the assessment of intrahepatic HBV cccDNA. In the last decade, several studies have investigated the performance of hepatitis B core-related antigen (HBcrAg) as a surrogate of HBV cccDNA amount in the liver. In this meta-analysis, we collected 14 studies (1271 patients) investigating the correlation between serum HBcrAg and intrahepatic HBV cccDNA. Serum HBcrAg showed a high correlation with intrahepatic HBV cccDNA (r = 0.641, 95% confidence interval (CI) 0.510–0.743, p < 0.001). In a head-to-head comparison, we observed that the performance of HBcrAg was significantly superior to that of hepatitis B surface antigen (r = 0.665 vs. r = 0.475, respectively, p < 0.001). Subgroup analysis showed that the correlation between HBcrAg and intrahepatic HBV cccDNA was high, both in hepatitis B e antigen-positive and -negative patients (r = 0.678, 95% CI 0.403–0.840, p < 0.001, and r = 0.578, 95% CI 0.344–0.744, p < 0.001, respectively). In conclusion, the measurement of serum HBcrAg qualifies as a reliable non-invasive surrogate for the assessment of an intrahepatic HBV cccDNA reservoir.

scholarly journals Hepatitis B Virus Replication Is Associated with an HBx-Dependent Mitochondrion-Regulated Increase in Cytosolic Calcium Levels

2007 ◽  
Vol 81 (21) ◽  
pp. 12061-12065 ◽  
Author(s):  
Stephanie L. McClain ◽  
Amy J. Clippinger ◽  
Rebecca Lizzano ◽  
Michael J. Bouchard
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Molecular Mechanisms ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Cytosolic Calcium ◽  
Hbv Replication ◽  
B Virus

ABSTRACT The nonstructural hepatitis B virus (HBV) protein HBx has an important role in HBV replication and in HBV-associated liver disease. Many activities have been linked to HBx expression; however, the molecular mechanisms underlying many of these activities are unknown. One proposed HBx function is the regulation of cytosolic calcium. We analyzed calcium levels in HepG2 cells that expressed HBx or replicating HBV, and we demonstrated that HBx, expressed in the absence of other HBV proteins or in the context of HBV replication, elevates cytosolic calcium. We linked this elevation of cytosolic calcium to the association of HBx with the mitochondrial permeability transition pore.

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