scholarly journals Small Interfering RNA Screening for the Small GTPase Rab Proteins Identifies Rab5B as a Major Regulator of Hepatitis B Virus Production

2019 ◽  
Vol 93 (15) ◽  
Author(s):  
Jun Inoue ◽  
Masashi Ninomiya ◽  
Teruyuki Umetsu ◽  
Takuya Nakamura ◽  
Takayuki Kogure ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Vesicular Trafficking ◽  
Hbv Infection ◽  
Rab Proteins ◽  
Early Endosomes ◽  
B Virus ◽  
Interfering Rna

ABSTRACTViruses are considered to use vesicular trafficking in infected cells, but the details of assembly/release pathways of hepatitis B virus (HBV) are still unknown. To identify key regulators of HBV production, we performed short interfering RNA (siRNA) screening for Rab proteins, which are considered to act as molecular switches in vesicular trafficking using HepG2.2.15 cells. Among 62 Rab proteins, the suppression of Rab5B most significantly increased HBV DNA in the culture supernatant. Surprisingly, 5 days after the transfection of Rab5B siRNA, HBV DNA in the supernatant was increased more than 30-fold, reflecting the increase of infectious HBV particles. Northern blotting showed that transcription of 2.4/2.1-kb mRNA coding envelope proteins containing large hepatitis B surface protein (LHBs) was increased. Analysis of hepatocyte nuclear factors (HNFs) showed that transcription of HNF4α, which is known to enhance 2.4-kb mRNA transcription, was regulated by Rab5B. Also, it was revealed that LHBs had accumulated in the endoplasmic reticulum (ER) after Rab5B depletion but not in the multivesicular body (MVB), which is thought to be an organelle utilized for HBV envelope formation. Therefore, it was considered that Rab5B is required for the transport of LHBs from the ER to MVB. Immunofluorescent microscopy showed that HBs proteins, including LHBs, colocalized with HBc in the ER of Rab5B-depleted cells, suggesting that HBV envelopment occurs not only in the MVB but also in the ER. In conclusion, Rab5B is a key regulator of HBV production and could be a target of antiviral therapy.IMPORTANCEHBV infection is a worldwide health problem, but the mechanisms of how HBV utilizes cellular machinery for its life cycle are poorly understood. In particular, it has been unclear how the viral components and virions are transported among the organelles. The HBV budding site has been reported to be the ER or MVB, but it has not been clearly determined. In this study, siRNA-based screening of Rab proteins using HBV-expressing cells showed that Rab5B, one of the Rab5 isoforms, has important roles in late steps of the HBV life cycle. Although Rab5 is known to work on early endosomes, this study showed that Rab5B plays a role in the transport of LHBs between the ER and MVB. Furthermore, it affects the transcription of LHBs. This is the first report on the mechanisms of HBV envelope protein transport among the organelles, and the results provide important insights into the therapeutic control of HBV infection.

scholarly journals Endemic hepatitis B virus (HBV) among hospital in-patients in Bangladesh, including evidence of occult infection

2020 ◽  
Author(s):  
Fazle Rabbi Chowdhury ◽  
Anna L McNaughton ◽  
Mohammad Robed Amin ◽  
Lovely Barai ◽  
Mili Rani Saha ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Occult Hepatitis ◽  
Treatment And Prevention ◽  
B Virus ◽  
High Prevalence ◽  
Hospital Patients ◽  
Surface Gene

ABSTRACTBangladesh is one of the world’s top ten burdened countries for viral hepatitis. We investigated an adult fever cohort (n=201) recruited in Dhaka, to determine the prevalence of hepatitis B virus (HBV) infection and to identify cases of occult hepatitis B infection (OBI). HBV exposure (anti-HBc) was documented in 72/201 (36%), and active HBV infection in 16/201 (8%), among whom 3 were defined as OBI (defined as detectable HBV DNA but negative HBsAg). Applying a target-enrichment sequencing pipeline to samples with HBV DNA >3.0log10 IU/ml, we obtained deep whole genome sequences for four cases, identifying genotypes A, C and D. Polymorphisms in the surface gene of the OBI case may account for the negative HBsAg status. We identified mutations associated with nucleos(t)ide analogue resistance, although the clinical significance in this cohort is not known. The high prevalence of HBV in this setting highlights the benefits of offering screening in hospital patients and the importance of HBV DNA testing of transfusion products to reduce the risk of transmission. In order to work towards international Sustainable Development Goal targets for HBV elimination, increased investment is required for diagnosis, treatment and prevention in Bangladesh.

scholarly journals Primary Tupaia Javanica Hepatocyte Culture as an In Vitro Model for Human Hepatitis B Virus Infection

2022 ◽  
Vol 22 (3) ◽  
pp. 203-209
Author(s):  
Kemal Fariz Kalista ◽  
Maryati Surya ◽  
Silmi Mariya ◽  
Diah Iskandriati ◽  
Irsan Hasan ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
In Vitro Model ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Primate Research ◽  
Qualitative And Quantitative ◽  
B Virus ◽  
Vitro Model

Background: Hepatitis B virus (HBV) infection is still one of the biggest health problems in the world, which could lead to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Treatment for HBV infection has not yet achieved a functional cure. More studies are needed to investigate human HBV (HuHBV), but the scarcity of animal models for HuHBV infection became a barrier. Recently, many studies have shown that Tupaia are suitable for the study of HuHBV. The purpose of this study was to develop a primary tupaia hepatocyte (PTH) culture from T. javanica, a species of Tupaia found in Indonesia, and to prove that HuHBV can replicate in the PTH.Method: In vitro experimental study using PTH isolated from five wild adult T. javanica in Primate Research Center, IPB University. HuHBV was taken from humans with HBsAg and HBV-DNA (+). PTH cells then were infected with HuHBV after reaching 80% confluence. Observation on PTH cells was done everyday for 20 days. Qualitative and quantitative HBsAg were measured using a CMIA while HBV-DNA and cccDNA were measured by RT-PCR.Results: A cytopathic effect was seen on day post infection (DPI)-16. HBsAg and HBV-DNA were detected from DPI-2 until DPI-18, with HBV-DNA level peaked on DPI-12. cccDNA concentration was fluctuating from DPI-2 until DPI-20 with highest level on DPI-16.Conclusion: HuHBV could infect and replicate in PTH from T. javanica can be infected with HuHBV and HuHBV can replicate in the PTH from T. javanica.

The risk of hepatitis B virus infection by transfusion in Kumasi, Ghana

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2419-2425 ◽  
Author(s):  
Jean-Pierre Allain ◽  
Daniel Candotti ◽  
Kate Soldan ◽  
Francis Sarkodie ◽  
Bruce Phelps ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Blood Donors ◽  
Hepatitis B Surface Antigen ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Sub Saharan Africa ◽  
B Virus ◽  
Sub Saharan ◽  
Hbv Transmission

The risk of hepatitis B virus (HBV) transmission by transfusion in sub-Saharan Africa is considered to be relatively low, and testing of blood donors is often not done or is done relatively poorly. To re-examine this attitude, we identified HBV chronically infected blood donors from a major hospital in Ghana with a range of hepatitis B surface antigen (HBsAg) assays. Test efficacy was estimated using HBV DNA as a gold standard, and the risk of HBV infection in blood recipients was estimated for different testing strategies. Particle agglutination, dipstick, and enzyme immunoassay (EIA) HBsAg screening detected 54%, 71%, and 97% of HBV infectious donors, respectively. The risk of HBV transmission to recipients less than 10 years old ranged between 1:11 and 1:326 with blood unscreened and screened by EIA, respectively. For older recipients, the risk decreased a further 4-fold because of the high frequency of natural exposure to HBV. A total of 98% of HBsAg-confirmed positive samples contained HBV DNA. HBV DNA load was less than 1 × 104 IU/mL in 75% of HBsAg-reactive samples, most of them anti-HBe reactive. Approximately 0.5% of HBsAg-negative but anti-HBc-positive samples contained HBV DNA. The use of sensitive HBsAg tests is critical to prevent transfusion transmission of HBV infection to young children in a population with a 15% prevalence of chronic HBV infection in blood donors. However, this will not have much effect on the prevalence of this infection unless other strategies to protect children from infection are also advanced in parallel.

A new method of concentrating hepatitis B virus (HBV) DNA and HBV surface antigen: an application of the method to the detection of occult HBV infection

Vox Sanguinis ◽  
2008 ◽  
Vol 95 (3) ◽  
pp. 174-180 ◽  
Author(s):  
K. Satoh ◽  
A. Iwata-Takakura ◽  
A. Yoshikawa ◽  
Y. Gotanda ◽  
T. Tanaka ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Surface Antigen ◽  
Hbv Dna ◽  
Hbv Infection ◽  
New Method ◽  
Occult Hbv Infection ◽  
Occult Hbv ◽  
B Virus

scholarly journals Low Risk of Hepatitis B Virus Reactivation in HBsAg-negative/Anti-HBc–positive Carriers Receiving Rituximab for Rheumatoid Arthritis: A Retrospective Multicenter Italian Study

2016 ◽  
Vol 43 (5) ◽  
pp. 869-874 ◽  
Author(s):  
Valentina Varisco ◽  
Mauro Viganò ◽  
Alberto Batticciotto ◽  
Pietro Lampertico ◽  
Antonio Marchesoni ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatitis B Surface Antigen ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Core Antigen ◽  
Hbv Reactivation ◽  
Serum Hbsag ◽  
B Virus

Objective.Patients with resolved hepatitis B virus (HBV) infection, i.e., hepatitis B surface antigen (HBsAg)-negative/antihepatitis B core antigen (anti-HBc)-positive, undergoing rituximab (RTX)-based chemotherapy for hematological malignancies without anti-HBV prophylaxis are at risk of HBV reactivation, but the risk in such patients receiving RTX for rheumatological disorders is not clear. We evaluated this risk in HBsAg-negative/anti-HBc–positive patients with rheumatoid arthritis (RA) undergoing RTX without prophylaxis.Methods.Thirty-three HBsAg-negative/anti-HBc–positive outpatients with RA with undetectable HBV DNA by sensitive PCR assay [73% women, median age 60 years, 85% with HBsAg antibodies (anti-HBs), 37% with antihepatitis B envelope antigen] received a median of 3 cycles of RTX (range 1–8) over 34 months (range 0–80) combined with disease-modifying antirheumatic drugs (DMARD) without prophylaxis. All underwent clinical and laboratory monitoring during and after RTX administration, including serum HBsAg and HBV DNA measurements every 6 months or whenever clinically indicated.Results.None of the patients seroreverted to HBsAg during RTX treatment, but 6/28 (21%) showed a > 50% decrease in protective anti-HBs levels, including 2 who became anti-HBs–negative. One patient (3%) who became HBV DNA-positive (44 IU/ml) after 6 months of RTX treatment was effectively rescued with lamivudine before any hepatitis flare occurred. Among the 14 patients monitored for 18 months (range 0–70) after RTX discontinuation, no HBV reactivation was observed.Conclusion.The administration of RTX + DMARD in patients with RA with resolved HBV infection leads to a negligible risk of HBV reactivation, thus suggesting that serum HBsAg and/or HBV DNA monitoring but not universal anti-HBV prophylaxis is justified.

Prevalence of hepatitis B virus infection in The Netherlands in 1996 and 2007

2011 ◽  
Vol 140 (8) ◽  
pp. 1469-1480 ◽  
Author(s):  
S. J. M. HAHNÉ ◽  
H. E. DE MELKER ◽  
M. KRETZSCHMAR ◽  
L. MOLLEMA ◽  
F. R. VAN DER KLIS ◽  
...  
Keyword(s):  
Risk Factors ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
The Netherlands ◽  
Hepatitis B Surface Antigen ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Core Antigen ◽  
Foreign Born ◽  
B Virus

SUMMARYWe aimed to assess differences in the prevalence of hepatitis B virus (HBV) infection in The Netherlands between 1996 and 2007, and to identify risk factors for HBV infection in 2007. Representative samples of the Dutch population in 1996 and 2007 were tested for antibodies to hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and HBV-DNA. In 2007, the weighted anti-HBc prevalence was 3·5% (95% CI 2·2–5·5) and the HBsAg prevalence was 0·2% (95% CI 0·1–0·4). In indigenous Dutch participants, the anti-HBc prevalence was lower in 2007 than in 1996 (P=0·06). First-generation migrants (FGMs) had a 13-fold greater risk of being HBsAg- and/or HBV-DNA-positive than indigenous Dutch participants. In indigenous Dutch participants, risk factors for anti-HBc positivity were older age and having received a blood product before 1990. In FGMs, being of Asian origin was a risk factor. In second-generation migrants, having a foreign-born partner and injecting drug use were risk factors. FGMs are the main target group for secondary HBV prevention in The Netherlands.

scholarly journals Significance of Hepatitis B Virus Diagnosis by Real-time Polymerase Chain Reaction over Serological Markers in Hepatitis B Virus Patients

2020 ◽  
Vol 4 (1) ◽  
pp. 52-56
Author(s):  
Amer A. Khaleel ◽  
Salah T. Jalal ◽  
Saeed G. Hussain
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Quantitative Estimation ◽  
Hbv Dna ◽  
Hbv Infection ◽  
Chain Reaction ◽  
Hbs Antigen ◽  
B Virus ◽  
Nucleic Acid Assay ◽  
Polymerase Chain

Hepatitis B virus (HBV) is the leading cause of viral hepatitis, as currently over 2 billion people have HBV infection worldwide. Nucleic acid assay and quantitative hepatitis B surface antigen (HBsAg) have been developed for diagnostic and therapeutic monitoring of patients with HBV infection. These tests might also show correlation between HBV DNA and HBs serostatus. The study aimed to find and analyze the frequency and impact of HBsAg seropositivity among patients revealed HBV DNA negative level through quantitative estimation of both seromarkers. Real-time polymerase chain reaction (RT-PCR) and Elecsys assays were used for quantitative estimation of HBV DNA and HBs antigen, respectively. A total of 256 blood samples were used from patients referred for either diagnostic purpose and/or HBV viral load monitoring after antiviral therapy. Blood profile analysis showed 12.26% HBs antigen seropositivity among patients revealed negative for nucleic acid assay for HBV DNA. Positive HBs antigen titers ranged from 1000–50,000 COI, with seronegative anti-HBs antibody test for all samples tested positive for HBs antigen. This study delineated that negative or undetectable quantitation of HBV DNA level does not exclude HBV infection; as the level might fluctuate in different phases of HBV replication. This gives an impression and raising a question about significance of replacing test for HBsAg with quantitation of HBV DNA PCR assay. Thus, the study refers to a special HBV profile outside the classical pattern.

scholarly journals Antiviral Properties and Mechanism of Action Studies of the Hepatitis B Virus Capsid Assembly Modulator JNJ-56136379

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Jan Martin Berke ◽  
Pascale Dehertogh ◽  
Karen Vergauwen ◽  
Wendy Mostmans ◽  
Koen Vandyck ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Hbv Dna ◽  
Size Exclusion ◽  
Capsid Assembly ◽  
Phase Ii Trials ◽  
B Virus

ABSTRACT Capsid assembly is a critical step in the hepatitis B virus (HBV) life cycle, mediated by the core protein. Core is a potential target for new antiviral therapies, the capsid assembly modulators (CAMs). JNJ-56136379 (JNJ-6379) is a novel and potent CAM currently in phase II trials. We evaluated the mechanisms of action (MOAs) and antiviral properties of JNJ-6379 in vitro. Size exclusion chromatography and electron microscopy studies demonstrated that JNJ-6379 induced the formation of morphologically intact viral capsids devoid of genomic material (primary MOA). JNJ-6379 accelerated the rate and extent of HBV capsid assembly in vitro. JNJ-6379 specifically and potently inhibited HBV replication; its median 50% effective concentration (EC50) was 54 nM (HepG2.117 cells). In HBV-infected primary human hepatocytes (PHHs), JNJ-6379, when added with the viral inoculum, dose-dependently reduced extracellular HBV DNA levels (median EC50 of 93 nM) and prevented covalently closed circular DNA (cccDNA) formation, leading to a dose-dependent reduction of intracellular HBV RNA levels (median EC50 of 876 nM) and reduced antigen levels (secondary MOA). Adding JNJ-6379 to PHHs 4 or 5 days postinfection reduced extracellular HBV DNA and did not prevent cccDNA formation. Time-of-addition PHH studies revealed that JNJ-6379 most likely interfered with postentry processes. Collectively, these data demonstrate that JNJ-6379 has dual MOAs in the early and late steps of the HBV life cycle, which is different from the MOA of nucleos(t)ide analogues. JNJ-6379 is in development for chronic hepatitis B treatment and may translate into higher HBV functional cure rates.

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