scholarly journals Strategies to Inhibit Hepatitis B Virus at the Transcript Level

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1327
Author(s):  
Bingqian Qu ◽  
Richard J. P. Brown
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Gene Transcription ◽  
Antigen Expression ◽  
Transcript Level ◽  
Viral Gene ◽  
Small Interfering Rnas ◽  
Viral Gene Transcription ◽  
Hbv Vaccination ◽  
B Virus

Approximately 240 million people are chronically infected with hepatitis B virus (HBV), despite four decades of effective HBV vaccination. During chronic infection, HBV forms two distinct templates responsible for viral transcription: (1) episomal covalently closed circular (ccc)DNA and (2) host genome-integrated viral templates. Multiple ubiquitous and liver-specific transcription factors are recruited onto these templates and modulate viral gene transcription. This review details the latest developments in antivirals that inhibit HBV gene transcription or destabilize viral transcripts. Notably, nuclear receptor agonists exhibit potent inhibition of viral gene transcription from cccDNA. Small molecule inhibitors repress HBV X protein-mediated transcription from cccDNA, while small interfering RNAs and single-stranded oligonucleotides result in transcript degradation from both cccDNA and integrated templates. These antivirals mediate their effects by reducing viral transcripts abundance, some leading to a loss of surface antigen expression, and they can potentially be added to the arsenal of drugs with demonstrable anti-HBV activity. Thus, these candidates deserve special attention for future repurposing or further development as anti-HBV therapeutics.

scholarly journals Strategies to Inhibit Hepatitis B Virus Gene Transcription

2021 ◽  
Author(s):  
Bingqian Qu ◽  
Richard J. P. Brown
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Gene Transcription ◽  
Antigen Expression ◽  
Viral Gene ◽  
Small Interfering Rnas ◽  
Hbv Vaccine ◽  
Viral Gene Transcription ◽  
B Virus ◽  
Surface Antigen Expression

Approximately 240 million people are chronically infected with hepatitis B virus (HBV), despite four decades of an effective HBV vaccine. During chronic infection, HBV forms two distinct templates responsible for viral gene transcription: (1) episomal covalently closed circular (ccc)DNA and (2) host-genome integrated viral templates. Multiple ubiquitous and liver-specific transcription factors are recruited onto these templates and modulate viral gene transcription. This review details the latest developments in antivirals that inhibit HBV gene transcription, and their impact on the stability of viral transcripts. Notably, nuclear receptor agonists exhibit potent inhibition of viral gene transcription from cccDNA, small molecule inhibitors repress HBV X protein-mediated transcription from cccDNA and small interfering RNAs and single-stranded oligonucleotides result in transcript degradation from both cccDNA and integrant templates. These antivirals mediate their effects by reducing viral transcripts abundance, eventually leading to loss of surface antigen expression, and can potentially be added to the arsenal of drugs with demonstrable anti-HBV activity. Thus, these candidates deserve special attention for future repurposing or further development as anti-HBV therapeutics.

scholarly journals Alpha interferon suppresses hepatitis B virus enhancer activity and reduces viral gene transcription.

1990 ◽  
Vol 64 (4) ◽  
pp. 1821-1824 ◽  
Author(s):  
R Tur-Kaspa ◽  
L Teicher ◽  
O Laub ◽  
A Itin ◽  
D Dagan ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Gene Transcription ◽  
Alpha Interferon ◽  
Viral Gene ◽  
Enhancer Activity ◽  
Viral Gene Transcription ◽  
B Virus

scholarly journals Type I Interferon Signaling Prevents Hepatitis B Virus-Specific T Cell Responses by Reducing Antigen Expression

2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Keigo Kawashima ◽  
Masanori Isogawa ◽  
Susumu Hamada-Tsutsumi ◽  
Ian Baudi ◽  
Satoru Saito ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
T Cell ◽  
Hepatitis B ◽  
Type I Interferon ◽  
T Cell Responses ◽  
Antigen Expression ◽  
Type I ◽  
Interferon Signaling ◽  
Cell Responses ◽  
B Virus

ABSTRACT Robust virus-specific CD8+ T cell responses are required for the clearance of hepatitis B virus (HBV). However, the factors that determine the magnitude of HBV-specific CD8+ T cell responses are poorly understood. To examine the impact of genetic variations of HBV on HBV-specific CD8+ T cell responses, we introduced three HBV clones (Aa_IND [Aa], C_JPN22 [C22], and D_IND60 [D60]) that express various amounts of HBV antigens into the livers of C57BL/6 (B6) (H-2b) mice and B10.D2 (H-2d) mice. In B6 mice, clone C22 barely induced HBV-specific CD8+ T cell responses and persisted the longest, while clone D60 elicited strong HBV-specific CD8+ T cell responses and was rapidly cleared. These differences between HBV clones largely diminished in H-2d mice. Interestingly, the magnitude of HBV-specific CD8+ T cell responses in B6 mice was associated with the HB core antigen expression level during the early phase of HBV transduction. Surprisingly, robust HBV-specific CD8+ T cell responses to clone C22 were induced in interferon-α/β receptor-deficient (IFN-αβR–/–) (H-2b) mice. The induction of HBV-specific CD8+ T cell responses to C22 in IFN-αβR–/– mice reflects enhanced HBV antigen expression because the suppression of antigen expression by HBV-specific small interfering RNA (siRNA) attenuated HBV-specific T cell responses in IFN-αβR–/– mice and prolonged HBV expression. Collectively, these results suggest that HBV genetic variation and type I interferon signaling determine the magnitude of HBV-specific CD8+ T cell responses by regulating the initial antigen expression levels. IMPORTANCE Hepatitis B virus (HBV) causes acute and chronic infection, and approximately 240 million people are chronically infected with HBV worldwide. It is generally believed that virus-specific CD8+ T cell responses are required for the clearance of HBV. However, the relative contributions of genetic variation and innate immune responses to the induction of HBV-specific CD8+ T cell responses are not fully understood. In this study, we discovered that different clearance rates between HBV clones after hydrodynamic transduction were associated with the magnitude of HBV-specific CD8+ T cell responses and initial HB core antigen expression. Surprisingly, type I interferon signaling negatively regulated HBV-specific CD8+ T cell responses by reducing early HBV antigen expression. These results show that the magnitude of the HBV-specific CD8+ T cell response is regulated primarily by the initial antigen expression level.

scholarly journals Paternal hepatitis B virus infection with different clinical courses between siblings

2021 ◽  
Author(s):  
Yoshiaki Sasaki ◽  
Hiroki Kajino
Keyword(s):  
Hepatitis B Virus ◽  
Virus Infection ◽  
Hepatitis B ◽  
Family Members ◽  
Hbv Infection ◽  
Hepatitis B Virus Infection ◽  
Hbv Vaccination ◽  
B Virus

No countermeasures have been established against horizontal infection in non-vaccinated children. We reported about siblings with different clinical courses of HBV paternal infection. To eradicate HBV, we should encourage HBV vaccination of all children and HBV infection screening of fathers and other family members.

Novel N-terminal amino acid sequence required for retention of a hepatitis B virus glycoprotein in the endoplasmic reticulum

1989 ◽  
Vol 9 (10) ◽  
pp. 4459-4466 ◽  
Author(s):  
K Kuroki ◽  
R Russnak ◽  
D Ganem
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Amino Acid Sequence ◽  
Essential Element ◽  
Viral Gene ◽  
Er Retention ◽  
B Virus ◽  
N Terminus

The preS1 surface glycoprotein of hepatitis B virus is targeted to the endoplasmic reticulum (ER) and is retained in this organelle when expressed in the absence of other viral gene products. The protein is also acylated at its N terminus with myristic acid. Sequences responsible for its ER retention have been identified through examination of mutants bearing lesions in the preS1 coding region. These studies reveal that such sequences map to the N terminus of the molecule, between residues 6 and 19. Molecules in which this region was present remained in the ER; those in which it had been deleted were secreted from the cell. Although all deletions which allowed efficient secretion also impaired acylation of the polypeptide, myristylation alone was not sufficient for ER retention: point mutations which eliminated myristylation did not lead to secretion. These data indicate that an essential element for ER retention resides in a 14-amino-acid sequence that is unrelated to previously described ER retention signals.

Entecavir Plus Pegylated Interferon and Sequential Hepatitis B Virus Vaccination Increases Hepatitis B Surface Antigen Seroclearance: A Randomized Controlled Proof-of-Concept Study

2020 ◽  
Author(s):  
Jeong-Hoon Lee ◽  
Yun Bin Lee ◽  
Eun Ju Cho ◽  
Su Jong Yu ◽  
Jung-Hwan Yoon ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis B Surface Antigen ◽  
Pegylated Interferon ◽  
Control Group ◽  
Proof Of Concept ◽  
Randomized Controlled ◽  
Hbv Vaccination ◽  
Hbsag Seroclearance ◽  
B Virus

Abstract Background Hepatitis B surface antigen (HBsAg) seroclearance is considered a functional cure for patients with chronic hepatitis B, but is rarely achievable with oral nucleos(t)ide analogues alone. We conducted a randomized controlled proof-of-concept trial to evaluate the impact of adding pegylated interferon (peg-IFN) alfa-2a plus sequential or concomitant hepatitis B virus (HBV) vaccination. Methods A total of 111 patients who achieved serum HBV DNA <20 IU/mL and quantitative HBsAg <3000 IU/mL with entecavir were randomly assigned (1:1:1) to the E + sVIP group (entecavir + peg-IFN alfa-2a [180 µg every week over 48 weeks] plus sequential HBV vaccination [20 µg of HBsAg on weeks 52, 56, 60, and 76]), the E + cVIP group (entecavir + peg-IFN alfa-2a + concomitant HBV vaccination [weeks 4, 8, 12, and 28]), or the control group (entecavir only). The primary endpoint was HBsAg seroclearance at week 100, and secondary endpoints included safety. Results No differences in baseline quantitative HBsAg were observed among the groups. The E + sVIP group in the intention-to-treat analysis showed a significantly higher chance of HBsAg seroclearance during week 100 than the control group (16.2% vs 0%; P = .025), but the E + cVIP group (5.4%) failed to reach a significant difference (P = .54). Adverse events were significantly more frequent in the E + sVIP (81.1%) and E + cVIP group (70.3%) than the control group (2.7%) (both P < .0001). However, the frequency of serious adverse events did not differ significantly among the 3 groups (2.7%, 5.4%, and 2.7%, respectively; P = 1.00). Conclusions Entecavir plus an additional peg-IFN alfa-2a treatment followed by sequential HBV vaccination under an intensified schedule significantly increases the chance of HBsAg seroclearance compared to entecavir alone. Clinical Trials Registration NCT02097004.

scholarly journals Interaction between STAT-3 and HNF-3 Leads to the Activation of Liver-Specific Hepatitis B Virus Enhancer 1 Function

2002 ◽  
Vol 76 (6) ◽  
pp. 2721-2729 ◽  
Author(s):  
Gulam Waris ◽  
Aleem Siddiqui
Keyword(s):  
Gene Expression ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Transcriptional Control ◽  
Viral Gene Expression ◽  
Cooperative Interaction ◽  
Viral Gene ◽  
Mobility Shift ◽  
B Virus ◽  
Stimulation Of

ABSTRACT The signal transducer and activator of transcription 3 (STAT-3), a member of the STAT family of proteins, binds to a large number of transcriptional control elements and regulates gene expression in response to cytokines. While it binds to its cognate nucleotide sequences, it has been recently shown to directly interact with other transcriptional factors in the absence of DNA. We report here one such novel interaction between STAT-3 and hepatocyte nuclear factor 3 (HNF-3) in the absence of DNA. We have identified a STAT-3 binding site within the core domain of hepatitis B virus (HBV) enhancer 1. The HBV enhancer 1 DNA-STAT-3 protein interaction is shown to be stimulated by interleukin-6 (IL-6) and epidermal growth factor, which leads to an overall stimulation of HBV enhancer 1 function and viral gene expression. Using mobility shift assays and transient transfection schemes, we demonstrate a cooperative interaction between HNF-3 and STAT-3 in mediating the cytokine-mediated HBV enhancer function. Cytokine stimulation of HBV gene expression represents an important regulatory scheme of direct relevance to liver disease pathogenesis associated with HBV infection.

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