Prospects for the Global Elimination of Hepatitis B

Impact of hepatic steatosis on liver stiffness measurement by vibration-controlled transient elastography and its diagnostic performance for identifying liver fibrosis in patients with chronic hepatitis B

OBJECTIVES

To explore the impact of hepatic steatosis measured by MRI-proton density fat fraction (MRI-PDFF) on liver stiffness measurement (LSM) value and its diagnostic performance for staging liver fibrosis in patients with chronic hepatitis B (CHB).

METHODS

A total of 914 patients with CHB who underwent liver biopsy and MRI-PDFF were retrospectively reviewed. The influence of MRI-PDFF on LSM value was assessed using univariate and multivariate linear analyses. To assess the influence of liver steatosis on the diagnostic performance of LSM, a series of ROC analyses were performed and compared by stratifying patients into non-steatosis (PDFF < 5%) and steatosis (PDFF ≥ 5%) groups according to MRI-PDFF values. The effects of different LSM cut-off values on the false-positive rate in the steatosis cohort were compared using McNemar's test.

RESULTS

LSM values were significantly affected by MRI-PDFF in the entire cohort (B-coefficient: 0.003, p < 0.001), F1 cohort (B-coefficient: 0.005, p < 0.001), and F2 cohort (B-coefficient: 0.003, p = 0.002). Hepatic steatosis was not observed to have a significant influence on the ROC curve of LSM for staging liver fibrosis. Compared with using the cut-off values for the CHB cohort, using relatively higher cut-off values for hepatic steatosis significantly improved the false-positive rate of LSM in the steatosis cohort.

CONCLUSION

Steatosis significantly influenced LSM, with a higher value in the early stage of liver fibrosis but did not affect the diagnostic efficiency of LSM for staging liver fibrosis. Moreover, using relatively high cut-off values significantly improved the false-positive rate of LSM in CHB patients with steatosis.

CLINICAL RELEVANCE STATEMENT

The identified correlation between MRI-PDFF and VCTE-measured LSM is not clinically relevant since the diagnostic performance of LSM in staging liver fibrosis is not affected by steatosis. A higher cut-off should be applied in CHB patients with steatosis to improve the false-positive rate.

KEY POINTS

Steatosis can affect liver stiff measurement (LSM) values in the early stage of liver fibrosis. The diagnostic performance of LSM in staging liver fibrosis is not affected by steatosis. LSM's cutoffs should be increased in patients with steatosis to improve the false-positive rate.

An Experimental Animal Study: Electroacupuncture Facilitates Antiviral Immunity Against Hepatitis B Virus Through the IFN-γ/JAK/STAT Axis

Background

Chronic hepatitis B (CHB) remains a global health challenge, necessitating innovative therapeutic strategies. Enhancing the body's immune response against the hepatitis B virus (HBV) emerges as a fundamental strategy for achieving a functional cure. While acupuncture has shown potential in immune modulation, its specific anti-HBV effects are not well understood. This study evaluates the potential of electroacupuncture (EA) in HBV infection and explores its underlying immunological mechanisms using a mouse model.

Methods

HBV-infected mice were established using the high-pressure hydrodynamic method and divided into four groups: normal saline (NS), EA, sham EA (SE), and tenofovir disoproxil fumarate (TF), with n = 6 per group. During treatment, blood was collected every Sunday via the orbital sinus to monitor HBV DNA, HBsAg, and HBeAg levels. Transcriptomics and metabolomics analyses were employed to unearth clues regarding EA's anti-HBV mechanism. Validation of these mechanisms included splenic T-cell flow analysis, Western blotting, RT-qPCR, immunofluorescence, and ELISA.

Results

Serum HBV DNA levels decreased by 1.10, 0.19, and 1.98 log10 IU/mL in the EA, SE, and TF-treated mice, respectively, compared to the NS. Concurrently, the hepatic HBV DNA levels decreased by 1.09, 0.24, and 2.03 log10 IU/mL. EA also demonstrated superior inhibition of HBV antigens, with serum HBeAg levels decreasing by 43.86%, 8.74%, and 8.03%, and serum HBsAg levels decreasing by 28.01%, 0.26%, and 9.39% in the EA, SE, and TF groups, respectively. Further analysis through transcriptomics and metabolomics revealed that EA's anti-HBV effects primarily hinge on immune modulation, particularly the IFN-γ/JAK/STAT pathway and taurine metabolism. EA also increased the ratio of splenic CD8+ CD69+ and CD8+ IFN-γ+ T-cells while upregulating key proteins in the JAK/STAT pathway and cytokines associated with antiviral immunity.

Conclusion

EA manifests inhibitory effects on HBV, particularly in antigen suppression, with its mode of action intricately linked to the regulation of IFN-γ/JAK/STAT.

AI Digital Pathology Using qFibrosis Shows Heterogeneity of Fibrosis Regression in Patients with Chronic Hepatitis B and C with Viral Response

This study aimed to understand the dynamic changes in fibrosis and its relationship with the evaluation of post-treatment viral hepatitis using qFibrosis. A total of 158 paired pre- and post-treatment liver samples from patients with chronic hepatitis B (CHB; n = 100) and C (CHC; n = 58) were examined. qFibrosis was employed with artificial intelligence (AI) to analyze the fibrosis dynamics in the portal tract (PT), periportal (PP), midzonal, pericentral, and central vein (CV) regions. All patients with CHB achieved a virological response after 78 weeks of treatment, whereas patients with CHC achieved a sustained viral response after 24 weeks. For patients initially staged as F5/6 (Ishak system) at baseline, the post-treatment cases exhibited a significant reduction in the collagen proportionate area (CPA) (25-69%) and number of collagen strings (#string) (9-72%) across all regions. In contrast, those initially staged as F3/4 at baseline showed a similar CPA and #string trend at 24 weeks. For regression patients, 27 parameters (25 in the CV region) in patients staged as F3/4 and 15 parameters (three in the PT and 12 in the PP regions) in those staged as F5/6 showed significant differences between the CHB and CHC groups at baseline. Following successful antiviral treatment, the pre- and post-treatment liver samples provided quantitative evidence of the heterogeneity of fibrotic features. qFibrosis has the potential to provide new insights into the characteristics of fibrosis regression in both patients with CHB and CHC as early as 24 weeks after antiviral therapy.

Discovery of hepatitis B virus subviral particle biogenesis inhibitors from a bioactive compound library

High levels of hepatitis B virus (HBV) surface antigen (HBsAg) in the blood of chronic HBV carriers are considered to drive the exhaustion of antigen-specific T and B lymphocytes and thus responsible for the persistence of infection. Accordingly, therapeutic elimination of HBsAg may facilitate the activation of adaptive antiviral immune responses against HBV and achieve a functional cure of chronic hepatitis B. We discovered recently that an amphipathic alpha helix spanning W156 to R169 of HBV small envelope (S) protein plays an essential role in the morphogenesis of subviral particles (SVPs) and metabolism of S protein. We thus hypothesized that pharmacological disruption of SVP morphogenesis may induce intracellular degradation of S protein and reduce HBsAg secretion. To identify inhibitors of SVP biogenesis, we screened 4417 bioactive compounds with a HepG2-derived cell line expressing HBV S protein and efficiently secreting small spherical SVPs. The screen identified 24 compounds that reduced intracellular SVPs and secreted HBsAg in a concentration-dependent manner. However, 18 of those compounds inhibited the secretion of HBsAg and HBeAg in HBV replicon transfected HepG2 cells at similar efficiency, suggesting each of those compounds may disrupt a common cellular function required for the synthesis and/or secretion of these viral proteins. Interestingly, lycorine more efficiently inhibited the secretion of HBsAg in HepG2 cells transfected with HBV replicons, HepG2.2.15 cells and HBV infected - HepG2 cells expressing sodium taurocholate cotransporting polypeptide (NTCP). The structure activity relationship and antiviral mechanism of lycorine against HBV have been determined.

Hepatitis B Virus Infection: A Mini Review

Hepatitis B and C viruses (HBV and HCV) are the leading causes of end-stage liver disease worldwide. Although there is a potent vaccine against HBV, many new infections are recorded annually, especially in poorly resourced places which have lax vaccination policies. Again, as HBV has no cure and chronic infection is lifelong, vaccines cannot help those already infected. Studies to thoroughly understand the HBV biology and pathogenesis are limited, leaving much yet to be understood about the genomic features and their role in establishing and maintaining infection. The current knowledge of the impact on disease progression and response to treatment, especially in hyperendemic regions, is inadequate. This calls for in-depth studies on viral biology, mainly for the purposes of coming up with better management strategies for infected people and more effective preventative measures for others. This information could also point us in the direction of a cure. Here, we discuss the progress made in understanding the genomic basis of viral activities leading to the complex interplay of the virus and the host, which determines the outcome of HBV infection as well as the impact of coinfections.

TRPV4 promotes HBV replication and capsid assembly via methylation modification of H3K4 and HBc ubiquitin

Hepatitis B virus (HBV) infection poses a significant burden on global public health. Unfortunately, current treatments cannot fully alleviate this burden as they have limited effect on the transcriptional activity of the tenacious covalently closed circular DNA (cccDNA) responsible for viral persistence. Consequently, the HBV life cycle should be further investigated to develop new anti-HBV pharmaceutical targets. Our previous study discovered that the host gene TMEM203 hinders HBV replication by participating in calcium ion regulation. The involvement of intracellular calcium in HBV replication has also been confirmed. In this study, we found that transient receptor potential vanilloid 4 (TRPV4) notably enhances HBV reproduction by investigating the effects of several calcium ion-related molecules on HBV replication. The in-depth study showed that TRPV4 promotes hepatitis B core/capsid protein (HBc) protein stability through the ubiquitination pathway and then promotes the nucleocapsid assembly. HBc binds to cccDNA and reduces the nucleosome spacing of the cccDNA-histones complex, which may regulate HBV transcription by altering the nucleosome arrangement of the HBV genome. Moreover, our results showed that TRPV4 promotes cccDNA-dependent transcription by accelerating the methylation modification of H3K4. In conclusion, TRPV4 could interact with HBV core protein and regulate HBV during transcription and replication. These data suggest that TRPV4 exerts multifaceted HBV-related synergistic factors and may serve as a therapeutic target for CHB.

Hypermethylation of the glutathione peroxidase 4 gene promoter is associated with the occurrence of immune tolerance phase in chronic hepatitis B

BACKGROUND

Hepatitis B virus (HBV) infection is a public health problem that seriously threatens human health. This study aimed to investigate the clinical significance of glutathione peroxidase 4(GPX4) in the occurrence and development of chronic hepatitis B (CHB).

METHODS

A total of 169 participants including 137 patients with CHB and 32 healthy controls (HCs) were recruited. We detected the expression of GPX4 and stimulator of interferon genes (STING) in peripheral blood mononuclear cells (PBMCs) by real-time quantitative polymerase chain reaction (RT-qPCR). The methylation level of GPX4 gene promoter in PBMCs was detected by TaqMan probe-based quantitative methylation-specific PCR (MethyLight). Enzyme-linked immunosorbent assay (ELISA) was performed to detect the serum levels of GPX4, IFN-β, oxidative stress (OS) related molecules, and pro-inflammatory cytokines.

RESULTS

The expression levels of GPX4 in PBMCs and serum of CHB patients were lower than those of HCs, but the methylation levels of GPX4 promoter were higher than those of HCs, especially in patients at the immune tolerance phase. STING mRNA expression levels in PBMCs and serum IFN-β levels of patients at the immune activation phase and reactivation phase of CHB were higher than those at other clinical phases of CHB and HCs. GPX4 mRNA expression level and methylation level in PBMCs from patients with CHB had a certain correlation with STING and IFN-β expression levels. In addition, the methylation level of the GPX4 promoter in PBMCs from patients with CHB was correlated with molecules associated with OS and inflammation.

CONCLUSIONS

GPX4 may play an important role in the pathogenesis and immune tolerance of CHB, which may provide new ideas for the functional cure of CHB.

Overview of the immunological mechanisms in hepatitis B virus reactivation: Implications for disease progression and management strategies

Hepatitis B virus (HBV) reactivation is a clinically significant challenge in disease management. This review explores the immunological mechanisms underlying HBV reactivation, emphasizing disease progression and management. It delves into host immune responses and reactivation's delicate balance, spanning innate and adaptive immunity. Viral factors' disruption of this balance, as are interactions between viral antigens, immune cells, cytokine networks, and immune checkpoint pathways, are examined. Notably, the roles of T cells, natural killer cells, and antigen-presenting cells are discussed, highlighting their influence on disease progression. HBV reactivation's impact on disease severity, hepatic flares, liver fibrosis progression, and hepatocellular carcinoma is detailed. Management strategies, including anti-viral and immunomodulatory approaches, are critically analyzed. The role of prophylactic anti-viral therapy during immunosuppressive treatments is explored alongside novel immunotherapeutic interventions to restore immune control and prevent reactivation. In conclusion, this comprehensive review furnishes a holistic view of the immunological mechanisms that propel HBV reactivation. With a dedicated focus on understanding its implications for disease progression and the prospects of efficient management strategies, this article contributes significantly to the knowledge base. The more profound insights into the intricate interactions between viral elements and the immune system will inform evidence-based approaches, ultimately enhancing disease management and elevating patient outcomes. The dynamic landscape of management strategies is critically scrutinized, spanning anti-viral and immunomodulatory approaches. The role of prophylactic anti-viral therapy in preventing reactivation during immunosuppressive treatments and the potential of innovative immunotherapeutic interventions to restore immune control and proactively deter reactivation.

Structural basis for nuclear import of hepatitis B virus (HBV) nucleocapsid core

Nuclear import of the hepatitis B virus (HBV) nucleocapsid is essential for replication that occurs in the nucleus. The ~360-angstrom HBV capsid translocates to the nuclear pore complex (NPC) as an intact particle, hijacking human importins in a reaction stimulated by host kinases. This paper describes the mechanisms of HBV capsid recognition by importins. We found that importin α1 binds a nuclear localization signal (NLS) at the far end of the HBV coat protein Cp183 carboxyl-terminal domain (CTD). This NLS is exposed to the capsid surface through a pore at the icosahedral quasi-sixfold vertex. Phosphorylation at serine-155, serine-162, and serine-170 promotes CTD compaction but does not affect the affinity for importin α1. The binding of 30 importin α1/β1 augments HBV capsid diameter to ~620 angstroms, close to the maximum size trafficable through the NPC. We propose that phosphorylation favors CTD externalization and prompts its compaction at the capsid surface, exposing the NLS to importins.

Mechanism of interferon alpha therapy for chronic hepatitis B and potential approaches to improve its therapeutic efficacy

Hepatitis B virus (HBV) chronically infects 296 million people worldwide and causes more than 820,000 deaths annually due to cirrhosis and hepatocellular carcinoma. Current standard-of-care medications for chronic hepatitis B (CHB) include nucleos(t)ide analogue (NA) viral DNA polymerase inhibitors and pegylated interferon alpha (PEG-IFN-α). NAs can efficiently suppress viral replication and improve liver pathology, but not eliminate or inactivate HBV covalently closed circular DNA (cccDNA). CCC DNA is the most stable HBV replication intermediate that exists as a minichromosome in the nucleus of infected hepatocyte to transcribe viral RNA and support viral protein translation and genome replication. Consequentially, a finite duration of NA therapy rarely achieves a sustained off-treatment suppression of viral replication and life-long NA treatment is most likely required. On the contrary, PEG-IFN-α has the benefit of finite treatment duration and achieves HBsAg seroclearance, the indication of durable immune control of HBV replication and functional cure of CHB, in approximately 5% of treated patients. However, the low antiviral efficacy and poor tolerability limit its use. Understanding how IFN-α suppresses HBV replication and regulates antiviral immune responses will help rational optimization of IFN therapy and development of novel immune modulators to improve the rate of functional cure. This review article highlights mechanistic insight on IFN control of HBV infection and recent progress in development of novel IFN regimens, small molecule IFN mimetics and combination therapy of PEG-IFN-α with new direct-acting antivirals and therapeutic vaccines to facilitate the functional cure of CHB.

CTCF regulates hepatitis B virus cccDNA chromatin topology

Hepatitis B Virus (HBV) is a small DNA virus that replicates via an episomal covalently closed circular DNA (cccDNA) that serves as the transcriptional template for viral mRNAs. The host protein, CCCTC-binding factor (CTCF), is a key regulator of cellular transcription by maintaining epigenetic boundaries, nucleosome phasing, stabilisation of long-range chromatin loops and directing alternative exon splicing. We previously reported that CTCF binds two conserved motifs within Enhancer I of the HBV genome and represses viral transcription, however, the underlying mechanisms were not identified. We show that CTCF depletion in cells harbouring cccDNA-like HBV molecules and in de novo infected cells resulted in an increase in spliced transcripts, which was most notable in the abundant SP1 spliced transcript. In contrast, depletion of CTCF in cell lines with integrated HBV DNA had no effect on the abundance of viral transcripts and in line with this observation there was limited evidence for CTCF binding to viral integrants, suggesting that CTCF-regulation of HBV transcription is specific to episomal cccDNA. Analysis of HBV chromatin topology by Assay for Transposase Accessible Chromatin Sequencing (ATAC-Seq) revealed an accessible region spanning Enhancers I and II and the basal core promoter (BCP). Mutating the CTCF binding sites within Enhancer I resulted in a dramatic rearrangement of chromatin accessibility where the open chromatin region was no longer detected, indicating loss of the phased nucleosome up- and down-stream of the HBV enhancer/BCP. These data demonstrate that CTCF functions to regulate HBV chromatin conformation and nucleosomal positioning in episomal maintained cccDNA, which has important consequences for HBV transcription regulation.

A Particle Gel Assay for Detection of Intracellular Hepatitis B Virus Subviral Particles in Cultured Cells

Chronic hepatitis B virus (HBV) infection is due to the failure of host immune system to resolve the viral infection. Accordingly, restoration or reconstitution of a functional antiviral immune response to HBV is essential to achieve durable control of HBV replication leading to a functional cure of chronic hepatitis B (CHB). Noninfectious subviral particles (SVPs), comprised of HBV surface antigen (HBsAg), are the predominant viral products secreted by HBV-infected hepatocytes. The high levels of SVPs in the circulation induce immune tolerance and contribute to the establishment of chronic HBV infection. The current standard-of-care medications for CHB efficiently suppress HBV replication but fail to reduce the levels of HBsAg in majority of treated patients. Further understanding the mechanisms underlying SVP morphogenesis, secretion and regulation by viral and host cellular factors are critical for the discovery of therapeutics that can inhibit SVP production and/or induce the degradation of HBV envelope proteins. We describe herein a protocol for intracellular SVP detection by a native agarose gel electrophoresis-based particle gel assy. The method is suitable for quantitative detection of intracellular HBV SVPs and can be applied in dissecting the molecular mechanism of SVP morphogenesis and the discovery of antiviral agents targeting SVP formation in hepatocytes.

Development of Polyvinyl Alcohol/Polyethylene Glycol Copolymer-based Orodispersible Films Loaded with Entecavir: Formulation and In vitro Characterization

PURPOSE

The aim of the study is to prepare entecavir (ETV)-loaded orodispersible films (ODFs) using polyvinyl alcohol (PVA)/polyethylene glycol (PEG) graft copolymer (Kollicoat® IR) as a film-forming agent, and further to evaluate the dissolution rate, mechanical and physicochemical properties of films.

METHODS

ETV-ODFs were prepared by a solvent casting method. The amount of film-forming agent, plasticizer, and disintegrating agent was optimized in terms of the appearance, thickness, disintegration time and mechanical properties of ODFs. The compatibility between the drug and each excipient was conducted under high temperature (60 °C), high humidity (RH 92.5%), and strong light (4500 Lx) for 10 days. The dissolution study of optimal ODFs compared with the original commercial tablet (Baraclude®) was performed using a paddle method in pH 1.0, pH 4.5, pH 6.8, and pH 7.4 media at 37 °C. The morphology of ODFs was observed via scanning electron microscopy (SEM). The mechanical properties such as tensile strength (TS), elastic modulus (EM), and percentage elongation (E%) of ODFs were evaluated using the universal testing machine. The physicochemical properties of ODFs were investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR).

RESULTS

The related substances were less than 0.5% under high temperature, high humidity, and strong light for 10 days when ETV was mixed with excipients. The optimal formulation of ODFs was set as the quality ratio of Kollicoat® IR, glycerol, sodium alginate (ALG-Na): TiO2: MCC+CMC-Na: ETV was 60:9:12:1:1:1. The drug-loaded ODFs were white and translucent with excellent stripping property. The thickness, disintegration time, EM, TS, and E% were 103.33±7.02 μm, 25.31±1.95 s, 25.34±8.69 Mpa, 2.14±0.26 Mpa, and 65.45±19.41 %, respectively. The cumulative drug release from ODFs was more than 90% in four different media at 10 min. The SEM showed that the drug was highly dispersible in ODFs, and the XRD, DSC, and FT-IR results showed that there occurred some interactions between the drug and excipients.

CONCLUSION

In conclusion, the developed ETV-loaded ODFs showed relatively short disintegration time, rapid drug dissolution, and excellent mechanical properties. This might be an alternative to conventional ETV Tablets for the treatment of chronic hepatitis B.

Effectiveness and Safety of Tenofovir Alafenamide in Treatment-Naïve and Treatment-Experienced Patients with Chronic Hepatitis B: Results of a Real-World Study from China

Background: Tenofovir alafenamide (TAF) has been effective against naïve patients with chronic hepatitis B (CHB) in phase 3 clinical trials. However, its real-world data are still limited. Objectives: This study aimed to investigate the effectiveness and safety of TAF in real-life situations in treatment-naïve (TN) and treatment-experienced (TE) CHB patients in China. Methods: This retrospective study enrolled TAF-treated patients between January 2019 and October 2020 at the outpatient clinic of West China Hospital. The primary endpoint was the rates of virologic response (VR), and the secondary endpoints were the proportion of normal alanine aminotransferase (ALT) and quantitative hepatitis B surface antigen (qHBsAg) levels. Safety endpoints comprised serum lipid profiles, changes in estimated glomerular filtration rate (eGFR), and serum creatinine (Scr). Results: A total of 161 TAF-treated patients were enrolled, including 49 TN patients and 112 TE patients. In the TN group, the VR rate at week 96 was 91.7% (22/24), and the proportion of normal ALT at week 96 was 95.8% (23/24). In the TE group, the VR rate at week 96 was 97.2% (69/71), and the proportion of normal ALT at week 96 was 90.1% (64/71). Serum qHBsAg levels decreased from 2930 to 1292 IU/mL in the TN group and 1158 to 533IU/mL in the TE group during 96 weeks of treatment (P = 0.05). For patients in the TN and TE groups, when compared to baseline measurements, serum creatinine increased (+7.91 vs. +6.62 mL/min/1.73 m2, P = 0.52) while eGFR decreased (-11.46 vs. -10.90 µmol/L, P = 0.82) at week 96. Simultaneously, triglycerides (TG) (+ 0.39 vs. + 0.31 mmol/L, P = 0.32), total cholesterol (TC) (+0.65 vs. +0.52 mmol/L, P = 0.02), and low-density lipoprotein cholesterol (LDL-C) (+0.25 vs. +0.25 mmol/L, P = 0.60) increased over time. Conclusions: TAF was highly effective in TN and TE CHB patients. However, there are potential risks in eGFR decrease and a continuous increase in lipidemia with the prolongation of medication time.

Design and analysis considerations for early phase clinical trials in hepatitis B (HBV) cure research: the ACTG A5394 study in persons with both HIV and HBV

With growing interest and efforts to achieve a hepatitis B (HBV) cure, HBV therapeutics have increasingly entered the clinical testing phase. In designing an early phase clinical trial aimed at HBV cure, the heterogeneity in participants and the choice of a biomarker endpoint that signals a cure requires careful consideration. We describe the key elements to consider during the development of HBV clinical trials aimed at a functional cure, and how we have addressed them in the design of a phase II AIDS Clinical Trials Group (ACTG) study, A5394 (NCT05551273). The trial we present is for persons with both HIV and HBV, a unique population that has much to gain from an HBV cure. Our decisions on the design elements are specific to the study agent and the targeted population, but our deliberations may be informative in the emerging field of early phase HBV trials aimed at cure.

Combination treatment of pegylated interferon and tenofovir versus tenofovir for people with chronic hepatitis B

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To evaluate the benefits and harms of pegylated interferon combined with tenofovir versus tenofovir monotherapy in adults with chronic hepatitis B.

The urgency to expand the antiviral indications of general chronic hepatitis B patients

In recent years, liver experts have conducted in-depth discussions on whether it is necessary to expand the indication of antiviral therapy for patients with chronic hepatitis B (CHB). Currently, the guidelines are too strict in treating CHB patients. With the deepening understanding of the natural history of hepatitis B virus infection, there is more and more evidence challenging the view that there is no disease progression and no treatment in the immune tolerance period and inactive period. As the price of antiviral agents for CHB has decreased significantly, the availability of antiviral agents for CHB has been considerably improved. Therefore, expanding the indications for antiviral treatment of CHB is of great significance in achieving the goal of eliminating the public health threat of viral hepatitis by 2030, as the World Health Organization has proposed.

Impact of potent nucleos(t)ide therapy on hepatitis B hospitalisations in Spain

BACKGROUND

Chronic hepatitis B virus (HBV) infection is a major cause of decompensated cirrhosis and liver cancer worldwide. Newborn HBV vaccination was implemented in Spain two decades ago, and potent oral antivirals entecavir and tenofovir were introduced around 2007.

AIM

To assess the clinical benefits of these interventions nationwide.

METHODS

Including HBV as a diagnosis, we performed a retrospective study of all hospitalisations in Spain the Spanish National Registry of Hospital Discharges. Information was retrieved from 1997 to 2017.

RESULTS

From 73,939,642 nationwide hospital admissions during the study period, 129,634 (0.17%) included HBV as diagnosis. Their number doubled from 2007 to 2017 and the median age increased from 44 to 58 years. Most HBV admissions recorded chronic hepatitis B. In-hospital death occurred in 6.4%. Co-infection with HIV or hepatitis C virus occurred in 11.9% and 23.3%, respectively. Patients with HIV-HBV co-infection had significantly greater mortality than individuals with HBV mono-infection. The rate of HBV hospitalisations significantly increased over time with a transient drop around 2007, coincident with the arrival of new potent oral antivirals. Although the proportion of HBV hepatic decompensation events has declined, the rate of liver cancer continues to rise. The small subset of patients with hepatitis delta superinfection increasingly and disproportionately accounts for hepatic decompensation events and liver cancer.

CONCLUSION

Hospital admissions of individuals with HBV infection are increasing in Spain. While hepatic decompensation events declined following the introduction of potent oral nucleos(t)ide therapy, HBV-related liver cancer is rising. No benefit of oral antiviral therapies is seen on hepatitis delta.

Heat Shock Protein Family A Member 1 Promotes Intracellular Amplification of Hepatitis B Virus Covalently Closed Circular DNA

Hepatitis B virus (HBV) contains a partially double-stranded relaxed circular DNA (rcDNA) genome that is converted into a covalently closed circular DNA (cccDNA) in the nucleus of the infected hepatocyte by cellular DNA repair machinery. cccDNA associates with nucleosomes to form a minichromosome that transcribes RNA to support the expression of viral proteins and reverse transcriptional replication of viral DNA. In addition to the de novo synthesis from incoming virion rcDNA, cccDNA can also be synthesized from rcDNA in the progeny nucleocapsids within the cytoplasm of infected hepatocytes via the intracellular amplification pathway. In our efforts to identify cellular DNA repair proteins required for cccDNA synthesis using a chemogenetic screen, we found that B02, a small-molecule inhibitor of DNA homologous recombination repair protein RAD51, significantly enhanced the synthesis of cccDNA via the intracellular amplification pathway in human hepatoma cells. Ironically, neither small interfering RNA (siRNA) knockdown of RAD51 expression nor treatment with another structurally distinct RAD51 inhibitor or activator altered cccDNA amplification. Instead, it was found that B02 treatment significantly elevated the levels of multiple heat shock protein mRNA, and siRNA knockdown of HSPA1 expression or treatment with HSPA1 inhibitors significantly attenuated B02 enhancement of cccDNA amplification. Moreover, B02-enhanced cccDNA amplification was efficiently inhibited by compounds that selectively inhibit DNA polymerase α or topoisomerase II, the enzymes required for cccDNA intracellular amplification. Our results thus indicate that B02 treatment induces a heat shock protein-mediated cellular response that positively regulates the conversion of rcDNA into cccDNA via the authentic intracellular amplification pathway. IMPORTANCE Elimination or functional inactivation of cccDNA minichromosomes in HBV-infected hepatocytes is essential for the cure of chronic hepatitis B virus (HBV) infection. However, lack of knowledge of the molecular mechanisms of cccDNA metabolism and regulation hampers the development of antiviral drugs to achieve this therapeutic goal. Our findings reported here imply that enhanced cccDNA amplification may occur under selected pathobiological conditions, such as cellular stress, to subvert the dilution or elimination of cccDNA and maintain the persistence of HBV infection. Therapeutic inhibition of HSPA1-enhanced cccDNA amplification under these pathobiological conditions should facilitate the elimination of cccDNA and cure of chronic hepatitis B.

Follow-up value of serum AFP and aminotransferases in chronic hepatitis B progression

Introduction

Chronic viral hepatitis (CH) is a stage prior to cirrhosis and primary cancer. Standard protocols for CH assessment during the long follow-up period are of great importance for precise treatment and living quality improvement. In this study, we aimed to analyze multiple serum indexes in chronic hepatitis B (CHB)-infected patients and to discuss their combined values in clinical applications.

Methods

Total 503 lines of laboratory data from 2012 to 2021 were extracted from103 CHB patients who were followed-up in our hospital. They were divided into the remission group and the progression group according to their complete clinical information and laboratory data. A series of models of serum indexes were analyzed to illustrate the fluctuation trend of @ach index in a time-dependent manner.

Results

The models revealed that abundant serum alpha-fetoprotein (AFP) in the remission group was characteristically associated with hepatocyte destruction markers aspartate aminotransferase (AST) and alanine aminotransferase and favored a much longer progression-free period (P 0.0001). A model-derived equation consisting of serum AFP and AST values showed a good performance (83% reliability) to distinguish the two groups.

Discussion

This study clearly demonstrates the intrinsic quantitative relationship between serum AFP and liver aminotransferases involving antivirus treatment response. The model-based equation compensates for serum hepatitis B virus DNA detection during outpatient follow-up and it may serve as a useful laboratory tool for CHB progression assessment.

Induction of a strong and long-lasting neutralizing immune response by dPreS1-TLR2 agonist nanovaccine against hepatitis B virus

Hepatitis B virus remains a major medical burden with more than 250 million chronically infected patients worldwide and 900,000 deaths each year, due to the disease progression towards severe complications (cirrhosis, hepatocellular carcinoma). Despite the availability of a prophylactic vaccine, this infection is still pandemic in Western Pacific and African regions, where around 6% of the adult population is infected. Among novel anti-HBV strategies, innovative drug delivery systems, such as nanoparticle platforms to deliver vaccine antigens or therapeutic molecules have been investigated. Here, we developed polylactic acid-based biodegradable nanoparticles as an innovative and efficient vaccine. They are twice functionalized by (i) the entrapment of Pam₃CSK₄, an immunomodulator and ligand to Toll-Like-Receptor 1/2, and by (ii) the adsorption/coating of myristoylated (2-48) derived PreS1 from the HBV surface antigen, identified as the major viral attachment site on hepatocytes. We demonstrate that such formulations mimic HBV virion with an efficient peptide recognition by the immune system, and elicit potent and durable antibody responses in naive mice during at least one year. We also show that the most efficient in vitro viral neutralization was observed with NP-Pam₃CSK₄-dPreS1 sera. The immunogenicity of the derived HBV antigen is modulated by the likely synergistic action of both the dPreS1 coated nanovector and the adjuvant moiety. This formulation represents a promising vaccine alternative to fight HBV infection.

Design, synthesis, and biological evaluation of novel sulfamoylbenzamide derivatives as HBV capsid assembly modulators

Capsid assembly modulators (CAMs) represent a novel class of antiviral agents targeting hepatitis B virus (HBV) capsid to disrupt the assembly process. NVR 3-778 is the first CAM to demonstrate antiviral activity in patients infected with HBV. However, the relatively low aqueous solubility and moderate activity in the human body halted further development of NVR 3-778. To improve the anti-HBV activity and the drug-like properties of NVR 3-778, we designed and synthesized a series of NVR 3-778 derivatives. Notably, phenylboronic acid-bearing compound 7b (EC50 = 0.83 ± 0.33 µM, CC50 = 19.4 ± 5.0 µM) displayed comparable anti-HBV activity to NVR 3-778 (EC50 = 0.73 ± 0.20 µM, CC50 = 23.4 ± 7.0 µM). Besides, 7b showed improved water solubility (328.8 µg/mL, pH 7) compared to NVR 3-778 (35.8 µg/mL, pH 7). Size exclusion chromatography (SEC) and quantification of encapsidated viral RNA were used to demonstrate that 7b behaves as a class II CAM similar to NVR 3-778. Moreover, molecular dynamics (MD) simulations were conducted to rationalize the structure-activity relationships (SARs) of these novel derivatives and to understand their key interactions with the binding pocket, which provide useful indications for guiding the further rational design of more effective anti-HBV drugs.

Compound IMB-Z inhibits hepatitis B virus replication through increasing APOBEC3G expression and incorporation into viral nucleocapsids

OBJECTIVES

As a host restriction factor, apolipoprotein B messenger RNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G or A3G) has been shown to suppress the replication of several viruses including hepatitis B virus (HBV). Recently, we reported that IMB-Z, a N-phenylbenzamide derivative, could inhibit Enterovirus 71 replication, and A3G mediated its antiviral activity. Whether IMB-Z exhibits an inhibitory effect on HBV replication has not been investigated.

MATERIAL AND METHODS

HBV DNA, pregenomic RNA (pgRNA), core protein, and capsid levels were determined by a qPCR assay or Southern blot, Northern blot, Western blot, and particle gel assay, respectively. Mutation analysis of HBV DNAs was conducted by a differential DNA denaturation PCR assay. A3G encapsidation into HBV nucleocapsids was examined by Western blot analysis after ultracentrifugation and a co-immunoprecipitation (IP) assay between HBV core and A3G proteins.

RESULTS

In the present study, we found that IMB-Z could considerably inhibit HBV replication in HepAD38 cells. Interestingly, IMB-Z did not alter the HBV pgRNA production but could reduce the level of core protein, viral nucleocapsids, and core-associated DNA, as well as cccDNA intracellular amplification. Similar to the action of IMB-Z's inhibition of Enterovirus 71 replication, we found that IMB-Z's inhibition of HBV replication was associated with increased level of A3G. Mechanistically, we demonstrated that the inhibitory effect of IMB-Z is independent of the cytidine deaminase activity of A3G and is exerted by increasing its incorporation into viral nucleocapsids.

CONCLUSIONS

Our results indicate that IMB-Z inhibits HBV through pharmacological induction A3G expression and incorporation into HBV nucleocapsids.

Evaluation of the effect of enhanced immunization in adults: A cross-sectional study in the southeast city of China

The efficacy of hepatitis B vaccination in adults was evaluated by comparison of the positive seroprotection rates and the hepatitis B surface antibody (anti-HBs) geometric mean titers (GMTs) between intensive intervention areas and non-intensive intervention areas after 8 years post-vaccination in the Zhejiang province. Seven cities (towns) in Zhejiang province were selected as intensive intervention areas, and adults in the demonstration areas receive hepatitis B vaccine voluntarily and for free. Other areas were non-intensive intervention areas. A total of 3587 participants received the full vaccination course (three doses), and blood samples were withdrawn 8 years after the first vaccination comprised the immunized group, and 2000 participants constituted the control group. The anti-HBs positive seroprotection rates of the immunized and control groups were 65.0% and 53.0%, respectively. The anti-HBs GMT of the subjects in the immunized group was 26.30 mIU/mL compared to 9.33 mIU/mL in the control group (P < .001). Significant differences were detected in the 24-35-, 36-45-, and 46-55-year-old subgroups in the positive seroprotection rates and the anti-HBs GMTs (P < .001) between the immunized and control groups. Moreover, significant differences were found in the anti-HBs GMT in the 46-55-year-old subgroup between the two groups (P = .02), while no differences were observed in the positive seroprotection rate (P = .428). In conclusion, adults who did not receive the hepatitis B vaccine in infancy and had negative serological markers of hepatitis B, especially adults <47-years-old, need vaccination.

Advances in Immunotherapy for Hepatitis B

Hepatitis B virus (HBV) is a hepatotropic virus with the potential to cause chronic infection, and it is one of the common causes of liver disease worldwide. Chronic HBV infection leads to liver cirrhosis and, ultimately, hepatocellular carcinoma (HCC). The persistence of covalently closed circular DNA (cccDNA) and the impaired immune response in patients with chronic hepatitis B (CHB) has been studied over the past few decades. Despite advances in the etiology of HBV and the development of potent virus-suppressing regimens, a cure for HBV has not been found. Both the innate and adaptive branches of immunity contribute to viral eradication. However, immune exhaustion and evasion have been demonstrated during CHB infection, although our understanding of the mechanism is still evolving. Recently, the successful use of an antiviral drug for hepatitis C has greatly encouraged the search for a cure for hepatitis B, which likely requires an approach focused on improving the antiviral immune response. In this review, we discuss our current knowledge of the immunopathogenic mechanisms and immunobiology of HBV infection. In addition, we touch upon why the existing therapeutic approaches may not achieve the goal of a functional cure. We also propose how combinations of new drugs, and especially novel immunotherapies, contribute to HBV clearance.

Cryo-EM structures of human hepatitis B and woodchuck hepatitis virus small spherical subviral particles

The loss of detectable hepatitis B surface antigen (HBsAg) is considered a functional cure in chronic hepatitis B. Naturally, HBsAg can be incorporated into the virion envelope or assembled into subviral particles (SVPs) with lipid from host cells. Until now, there has been no detailed structure of HBsAg, and the published SVP structures are controversial. Here, we report the first subnanometer-resolution structures of spherical SVP from hepatitis B virus (HBV) and the related woodchuck hepatitis virus (WHV) determined by cryo-electron microscopy in combination with AlphaFold2 prediction. Both structures showed unique rhombicuboctahedral symmetry with 24 protruding spikes comprising dimer of small HBsAg with four helical domains. The lipid moiety in the SVP is organized in a noncanonical lipid patch instead of a lipid bilayer, which can accommodate the exposed hydrophobic surface and modulate particle stability. Together, these findings advance our knowledge of viral membrane organization and the structures of HBV and WHV spherical SVPs.

Liver cancer and hepatic decompensation events in patients hospitalized with viral hepatitis in Spain

BACKGROUND

Chronic viral hepatitis B, C, and D are the main causes of decompensated cirrhosis and liver cancer worldwide. Newborn HBV vaccination was implemented more than 2 decades ago in most EU countries. Furthermore, potent oral antivirals have been available to treat HBV for 15 years and to cure HCV since 2014. The real-life clinical benefits of these interventions at country level have not been assessed, especially regarding major hepatic outcomes such as cirrhotic decompensation events and hepatocellular carcinoma (HCC).

METHODS

Retrospective study of all hospitalizations in Spain having HBV, HCV, and HDV as diagnosis using the Spanish National Registry of Hospital Discharges. Information was retrieved from 1997 up to 2017.

RESULTS

From a total of 73,939,642 hospital admissions during the study period, a diagnosis of HBV, HCV, and HDV was made in 124,915 (1.7‰), 981,985 (13.3‰), and 4850 (0.07‰) patients, respectively. The median age of patients hospitalized within each group was 53.2, 55.9, and 47.0 years, respectively. Significant increases in mean age at hospitalization occurred in all groups (0.6 years older per calendar year on average). The overall rate of hepatic decompensation events for HBV, HCV, and HDV was 12.1%, 14.1%, and 18.8%, respectively. For HCC hospitalizations, these figures were 6.7%, 8.0%, and 7.8%, respectively. Whereas, the rate of decompensation events declined in recent years for HBV, and more recently for HCV, it continued rising up for HDV. Likewise, liver cancer rates recently plateaued for HBV and HCV, but kept growing for HDV.

CONCLUSION

The rate of hepatic decompensation events and liver cancer has declined and/or plateaued in recent years for patients hospitalized with HBV and HCV infections, following the widespread use of oral antiviral therapies for these viruses. In contrast, the rate of decompensated cirrhotic events and HCC has kept rising up for patients with hepatitis delta, for which effective antiviral treatment does not exist yet.

The bioinformatics and experimental analysis of the novel roles of virus infection-associated gene CDC20 for prognosis and immune infiltration in hepatocellular carcinoma

Infection virus including HBV and HCV has been well recognized as a major cause inducing hepatocellular carcinoma (HCC). However, molecular investigations into the HTLV-1 (Human T-lymphotropic virus type-1) and HCC have been rare. In this study, we integrated several public datasets of HCC patients and filtered seven genes including CDC20 as the HTLV-1 infection-related genes which were differentially expressed in HCC. CDC20 was chosen for further investigation based on its promising prognostic power. The expression profiles, prognostic assessment, association with clinicopathologic characteristics, prediction of correlated signal pathways, and the immune-modulating function of CDC20 were assessed. We found that CDC20 expression was significantly increased in hepatocellular carcinoma tissues and cell lines, and was correlated with histologic grade, pathologic stage, tumor status, and patient age. CDC20 exhibited prognostic value on overall survival and disease specific survival and was an independent prognostic factor. It was primarily involved in several signal pathways, especially the omega-hydroxylase P450 and epoxygenase P450 signal pathways. Moreover, CDC20 expression showed significant positive associations with the levels of several immune cells such as T helper 2 cells and follicular helper T cells, immunostimulators including TNFRSF18 and MICB, immunoinhibitors including KDR and PDCD1LG2, chemokines including XCL1 and CCL26, and chemokine receptors including CCR10 and CXCR3. This study for the first time delineated the correlation of CDC20 with HTLV-1 infection-associated HCC. The disorder of expression and function of CDC20 makes it a probable biomarker for better etiological classification, prognostic prediction, and precision medicine.

Pharmacomodulation of a ligand targeting the HBV capsid hydrophobic pocket

Hepatitis B virus (HBV) is a small enveloped retrotranscribing DNA virus and an important human pathogen. Its capsid-forming core protein (Cp) features a hydrophobic pocket proposed to be central notably in capsid envelopment. Indeed, mutations in and around this pocket can profoundly modulate, and even abolish, secretion of enveloped virions. We have recently shown that Triton X-100, a detergent used during Cp purification, binds to the hydrophobic pocket with micromolar affinity. We here performed pharmacomodulation of pocket binders through systematic modifications of the three distinct chemical moieties composing the Triton X-100 molecule. Using NMR and ITC, we found that the flat aromatic moiety is essential for binding, while the number of atoms of the aliphatic chain modulates binding affinity. The hydrophilic tail, in contrast, is highly tolerant to changes in both length and type. Our data provide essential information for designing a new class of HBV antivirals targeting capsid–envelope interactions.

Small-molecule binding to the Hepatitis B virus core protein hydrophobic pocket, a possible strategy for targeting viral particle assembly.