Getting to HBV cure: The promising paths forward

Lappanolides A-N, fourteen undescribed sesquiterpenoids from Saussurea costus (Syn. Saussurea lappa) and their anti HBV activity

Lappanolides A-N (1-14), 14 undescribed sesquiterpenoids, along with 23 known ones (15-37), were isolated from the roots of Saussurea costus, which were primarily categorized into eudesmane, guaiane, and germacrane types. Lappanolide A (1) possessed an unprecedented pseudo-disesquiterpenoids. Their structures and absolute configurations were established using physical data analyses (HRESIMS, IR, 1D and 2D NMR) and ECD calculations. All isolated compounds were tested for anti-hepatitis B virus (anti-HBV) activity. Ten compounds (1, 9, 11, 12, 19, 22, 28, 29, 31, and 36) exhibited activities against HBsAg secretions as determined by ELISA assay, with IC50 values ranging from 5.2 to 45.7 μM. In particular, compounds 28 and 29 showed inhibition of HBsAg secretion with IC50 values of 5.28 and 5.30 μM, and CC50 values of 9.85 and 6.37 μM, respectively, though they all exhibited low selectivity. Several compounds displayed cytotoxicity in the MTT assay. Among them, compound 28 was the most notable and was chosen for further study using flow cytometry. The result showed that it significantly induced HepG2 cell arrest in the S phase and induced apoptosis.

Solamargine acts as an antiviral by interacting to MZF1 and targeting the core promoter of the hepatitis B virus gene

BACKGROUND

Hepatitis B virus (HBV) infection is still a serious threat to global health and can lead to a variety of liver diseases, including acute and chronic hepatitis, liver cirrhosis, liver failure, hepatocellular carcinoma (HCC), and so on. At present, there are mainly two kinds of drugs for the treatment of hepatitis B at home and abroad: interferon (IFN) and nucleoside/nucleotide analogs (NAs). In recent years, natural compounds have been considered an important source for the development of new anti-HBV drugs due to their complex structure, diverse components, high efficiency, and low toxicity. Many studies have demonstrated that Solamargine has significant anticancer activity, but the antiviral effect is rarely studied. This study aimed to verify the anti-HBV effect of Solamargine and to explore the specific mechanism.

METHOD

The relative expression of HBV pregenomic RNA (pgRNA) was detected by reverse transcription real-time fluorescence quantitative PCR (RT-qPCR). Northern blot and western blot were used to detect the relative expression of HBV pgRNA and target protein. PCR was used in the construction of HBV pg-promoter, ENII/BCP, and a series of gene deletion mutant fluorescent reporter vectors. The fluorescence relative expression of each mutant was detected by Renilla luciferase assay.

RESULTS

By binding to MZF1 (Myeloid zinc finger protein 1, MZF1), Solamargine inhibits HBV core promoter activity, reduces pregenomic RNA level, and inhibits HBV, achieving antiviral effects.

Colchicine-mediated selective autophagic degradation of HBV core proteins inhibits HBV replication and HBV-related hepatocellular carcinoma progression

The HBV core protein (HBc) is an important viral protein of HBV that plays an indispensable role in the lifecycle of HBV, including capsid assembly and transport, reverse transcription and virus release. In recent years, evidence has shown that HBc may be involved in the malignant progression of HCC. Thus, HBc is an attractive target for antiviral agents and provides a new strategy for the treatment of HBV-related HCC. Here, we identified a novel anti-HBc compound-colchicine, an alkaloid compound-that promoted selective autophagic degradation of HBc through the AMPK/mTOR/ULK1 signalling pathway. We further confirmed that colchicine promoted the selective autophagy of HBc by enhancing the binding of HBc to the autophagy receptor p62. Finally, we evaluated the effects of colchicine on HBV replication and HBc-mediated HCC metastasis in vitro and in vivo. Our research indicated that the inhibitory effects of colchicine on HBV and HBV-related HCC depend on the selective autophagic degradation of HBc. Thus, colchicine is not only a promising therapeutic strategy for chronic hepatitis B but also a new treatment for HBV-related HCC.

Role of hepatitis B core-related antigen in predicting the occurrence and recurrence of hepatocellular carcinoma in patients with chronic hepatitis B: A systemic review and meta-analysis

BACKGROUND AND AIM

The purpose of the current study was to investigate the predictive value of hepatitis B core-related antigen (HBcrAg) on the occurrence and recurrence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB).

METHODS

We searched PubMed, Embase, Scopus, and Web of Science from database inception to April 6, 2023. Pooled hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) was calculated for the occurrence and recurrence of HCC.

RESULTS

Of the 464 articles considered, 18 articles recruiting 10 320 patients were included. The pooled results showed that high serum HBcrAg level was an independent risk factor for the occurrence of HCC in CHB patients (adjusted HR = 3.12, 95% CI: 2.40-4.06, P < 0.001, I2 = 43.2%, P = 0.043; OR = 5.65, 95% CI: 3.44-5.82, P < 0.001, I2 = 0.00%, P = 0.42). Further subgroup analysis demonstrated that the predictive ability of HBcrAg for the occurrence of HCC is not influenced by the hepatitis B e antigen (HBeAg) status or the use of nucleoside/nucleotide analogs (NAs). In addition, our meta-analysis also suggests that HBcrAg is a predictor of HCC recurrence (adjusted HR = 1.71, 95% CI: 1.26-2.32, P < 0.001, I2 = 7.89%, P = 0.031).

CONCLUSIONS

For patients with CHB, serum HBcrAg may be a potential predictive factor for the occurrence of HCC, regardless of HBeAg status or NA treatment. It may also serve as a novel prognostic biomarker for the recurrence of HCC. More studies are needed to confirm our conclusions.

Hepatitis B Virus Infection in Eastern Libya: Current Efforts for Overcoming Regional Barriers for Its Elimination

Approximately 2.2% of Libyans have chronic hepatitis B (CHB) and are at the highest risk of developing end-stage disease complications. Several resource-limited countries, including Libya, may be far from achieving the WHO goal of hepatitis B elimination by 2030 as a result of several testing and linkage to care (LTC) barriers. In Libya, data about the current HBV infection situation is scarce. Therefore, our study aimed to evaluate the trends of HBV in eastern Libya, Tobruk region, and try to identify the region-specific gaps and barriers that could potentially delay the WHO goal of HBV elimination. An eighteen-year retrospective review of records of the main district medical center in the region was done to estimate the trends of HBV infection and qualitative interviews with the clinical staff of the CHB registry in the region were conducted to investigate the current status of HBV management. Out of 392,952 records, 371 (0.09%) HBV-positive were recorded and declining trends of the infection were noticed over the study period. Until late 2019, there was no linkage to care or follow-up for people with HBV infection. However, a CHB registry was established in late 2019 to manage HBV infections in the region, yet there are several barriers such as the lack of diagnostic infrastructure for liver function assessment and antiviral treatment. Despite the significant decline observed in the occurrence of HBV infection and introduction of important HBV management steps such as establishment of the CHB registry, there are still several barriers that could delay the elimination of the infection.

Metabolites from traditional Chinese botanical drugs with anti-hepatitis B virus activity - a review

Hepatitis B virus (HBV)-related liver disease poses a major threat to human health worldwide. Although interferon and nucleoside analogues are commonly administered for treating chronic HBV infection, their use is limited by considerable side effects, drug resistance and incapacity for HBV elimination. Hence, novel HBV therapeutics are urgently required. For numerous years, traditional Chinese botanical drugs have been widely used to treat HBV-related diseases. The natural metabolites derived from these traditional drugs exhibit significant anti-HBV effects and serve as potential novel drugs for treating HBV. For overall understanding the therapeutic potential of these metabolites, the anti-HBV effects and mechanisms of action of 107 natural metabolites are summarized in this article. Mechanistically, these natural metabolites exert their anti-HBV effects by influencing the expression and function of host and/or viral genes, which differs from the mechanism of action of nucleoside analogues. Indeed, combining natural metabolites with nucleoside analogues can exert synergistic effects. Accordingly, natural metabolites or their chemically modified derivatives represent potential novel drugs and adjuvants for anti-HBV treatment.

Discovery of Novel 2-Oxoacetamide Derivatives as B3GAT3 Inhibitors for the Treatment of Hepatocellular Carcinoma

Beta-1,3-glucuronosyltransferase (B3GAT3), overexpressed in hepatocellular carcinoma (HCC) and negatively correlated to prognosis, is a promising target for cancer therapy. Currently, no studies have reported small molecule inhibitors of B3GAT3. In this study, we designed and synthesized a series of small-molecule inhibitors of B3GAT3 through virtual screening and structure optimization. The lead compound TMLB-C16 exhibited potent B3GAT3 inhibitory activity (KD = 3.962 μM) by effectively suppressing proliferation and migration, and inducing cell cycle arrest and apoptosis in MHCC-97H (IC50= 6.53 ± 0.18 μM) and HCCLM3 (IC50= 6.22 ± 0.23 μM) cells. Furthermore, compound TMLB-C16 demonstrated favorable pharmacokinetic properties with a relatively high bioavailability of 68.37%. It significantly inhibited tumor growth in both MHCC-97H and HCCLM3 xenograft tumor models without causing obvious toxicity. These results indicate that compound TMLB-C16 is an effective small molecule inhibitor of B3GAT3, providing a basis for the future development of B3GAT3-targeted drugs.

Major open questions in the hepatitis B and D field - Proceedings of the inaugural International emerging hepatitis B and hepatitis D researchers workshop

The early and mid-career researchers (EMCRs) of scientific communities represent the forefront of research and the future direction in which a field takes. The opinions of this key demographic are not commonly aggregated to audit fields and precisely demonstrate where challenges lie for the future. To address this, we initiated the inaugural International Emerging Researchers Workshop for the global Hepatitis B and Hepatitis D scientific community (75 individuals). The cohort was split into small discussion groups and the significant problems, challenges, and future directions were assessed. Here, we summarise the outcome of these discussions and outline the future directions suggested by the EMCR community. We show an effective approach to gauging and accumulating the ideas of EMCRs and provide a succinct summary of the significant gaps remaining in the Hepatitis B and Hepatitis D field.

Single-cell landscape of functionally cured chronic hepatitis B patients reveals activation of innate and altered CD4-CTL-driven adaptive immunity

BACKGROUND & AIMS

Hepatitis B surface antigen (HBsAg) loss or functional cure (FC) is considered the optimal therapeutic outcome for patients with chronic hepatitis B (CHB). However, the immune-pathological biomarkers and underlying mechanisms of FC remain unclear. In this study we comprehensively interrogate disease-associated cell states identified within intrahepatic tissue and matched PBMCs (peripheral blood mononuclear cells) from patients with CHB or after FC, at the resolution of single cells, to provide novel insights into putative mechanisms underlying FC.

METHODS

We combined single-cell transcriptomics (single-cell RNA sequencing) with multiparametric flow cytometry-based immune phenotyping, and multiplexed immunofluorescence to elucidate the immunopathological cell states associated with CHB vs. FC.

RESULTS

We found that the intrahepatic environment in CHB and FC displays specific cell identities and molecular signatures that are distinct from those found in matched PBMCs. FC is associated with the emergence of an altered adaptive immune response marked by CD4 cytotoxic T lymphocytes, and an activated innate response represented by liver-resident natural killer cells, specific Kupffer cell subtypes and marginated neutrophils. Surprisingly, we found MHC class II-expressing hepatocytes in patients achieving FC, as well as low but persistent levels of covalently closed circular DNA and pregenomic RNA, which may play an important role in FC.

CONCLUSIONS

Our study provides conceptually novel insights into the immuno-pathological control of HBV cure, and opens exciting new avenues for clinical management, biomarker discovery and therapeutic development. We believe that the discoveries from this study, as it relates to the activation of an innate and altered immune response that may facilitate sustained, low-grade inflammation, may have broader implications in the resolution of chronic viral hepatitis.

IMPACT AND IMPLICATIONS

This study dissects the immuno-pathological cell states associated with functionally cured chronic hepatitis B (defined by the loss of HBV surface antigen or HBsAg). We identified the sustained presence of very low viral load, accessory antigen-presenting hepatocytes, adaptive-memory-like natural killer cells, and the emergence of helper CD4 T cells with cytotoxic or effector-like signatures associated with functional cure, suggesting previously unsuspected alterations in the adaptive immune response, as well as a key role for the innate immune response in achieving or maintaining functional cure. Overall, the insights generated from this study may provide new avenues for the development of alternative therapies as well as patient surveillance for better clinical management of chronic hepatitis B.

Current trends and advances in antiviral therapy for chronic hepatitis B

ABSTRACT

Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress HBV replication and improve the prognosis. However, the persistence of covalently closed circular DNA (cccDNA), the integration of HBV-DNA into the host genome, and compromised immune responses impede the successful treatment of hepatitis B. While achieving a functional cure of HBV remains elusive with the current treatment methods, this is the goal of new therapeutic approaches. Therefore, developing novel antiviral drugs is necessary for achieving a functional or complete cure for chronic hepatitis B. In recent years, substantial progress has been made in drug discovery and development for HBV infection. Direct-acting antiviral agents such as entry inhibitors, capsid assembly modulators, subviral particle release inhibitors, cccDNA silencers, and RNA interference molecules have entered clinical trials. In addition, several immunomodulatory agents, including toll-like receptor agonists, therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also making their way toward clinical use. In this review, we summarize the recent progress and limitations of chronic hepatitis B treatment and discuss perspectives on approaches to achieving functional cure. Although it will take some time for these new antiviral drugs to be widely used in clinical practice, combination therapy may become a preferable treatment option in the future.

High accuracy model for HBsAg loss based on longitudinal trajectories of serum qHBsAg throughout long-term antiviral therapy

OBJECTIVE

Hepatitis B surface antigen (HBsAg) loss is the optimal outcome for patients with chronic hepatitis B (CHB) but this rarely occurs with currently approved therapies. We aimed to develop and validate a prognostic model for HBsAg loss on treatment using longitudinal data from a large, prospectively followed, nationwide cohort.

DESIGN

CHB patients receiving nucleos(t)ide analogues as antiviral treatment were enrolled from 50 centres in China. Quantitative HBsAg (qHBsAg) testing was prospectively performed biannually per protocol. Longitudinal discriminant analysis algorithm was used to estimate the incidence of HBsAg loss, by integrating clinical data of each patient collected during follow-up.

RESULTS

In total, 6792 CHB patients who had initiated antiviral treatment 41.3 (IQR 7.6-107.6) months before enrolment and had median qHBsAg 2.9 (IQR 2.3-3.3) log10IU/mL at entry were analysed. With a median follow-up of 65.6 (IQR 51.5-84.7) months, the 5-year cumulative incidence of HBsAg loss was 2.4%. A prediction model integrating all qHBsAg values of each patient during follow-up, designated GOLDEN model, was developed and validated. The AUCs of GOLDEN model were 0.981 (95% CI 0.974 to 0.987) and 0.979 (95% CI 0.974 to 0.983) in the training and external validation sets, respectively, and were significantly better than those of a single qHBsAg measurement. GOLDEN model identified 8.5%-10.4% of patients with a high probability of HBsAg loss (5-year cumulative incidence: 17.0%-29.1%) and was able to exclude 89.6%-91.5% of patients whose incidence of HBsAg loss is 0. Moreover, the GOLDEN model consistently showed excellent performance among various subgroups.

CONCLUSION

The novel GOLDEN model, based on longitudinal qHBsAg data, accurately predicts HBsAg clearance, provides reliable estimates of functional hepatitis B virus (HBV) cure and may have the potential to stratify different subsets of patients for novel anti-HBV therapies.

N-Hydroxypiridinedione: A Privileged Heterocycle for Targeting the HBV RNase H

Hepatitis B virus (HBV) remains a global health threat. Ribonuclease H (RNase H), part of the virus polymerase protein, cleaves the pgRNA template during viral genome replication. Inhibition of RNase H activity prevents (+) DNA strand synthesis and results in the accumulation of non-functional genomes, terminating the viral replication cycle. RNase H, though promising, remains an under-explored drug target against HBV. We previously reported the identification of a series of N-hydroxypyridinedione (HPD) imines that effectively inhibit the HBV RNase H. In our effort to further explore the HPD scaffold, we designed, synthesized, and evaluated 18 novel HPD oximes, as well as 4 structurally related minoxidil derivatives and 2 barbituric acid counterparts. The new analogs were docked on the RNase H active site and all proved able to coordinate the two Mg2+ ions in the catalytic site. All of the new HPDs effectively inhibited the viral replication in cell assays exhibiting EC50 values in the low μM range (1.1-7.7 μM) with low cytotoxicity, resulting in selectivity indexes (SI) of up to 92, one of the highest reported to date among HBV RNase H inhibitors. Our findings expand the structure-activity relationships on the HPD scaffold, facilitating the development of even more potent anti-HBV agents.

Circulating metabolites are associated with persistent elevations of ALT in patients with chronic hepatitis B with complete viral suppression

Hepatitis B virus (HBV) can be completely suppressed after antiviral treatment; however, some patients with chronic hepatitis B (CHB) exhibit elevated alanine aminotransferase (ALT) levels and sustained disease progression. This study provides novel insights into the mechanism and potential predictive biomarkers of persistently elevated ALT (PeALT) in patients with CHB after complete viral inhibition. Patients having CHB with undetectable HBV DNA at least 12 months after antiviral treatment were enrolled from a prospective, observational cohort. Patients with PeALT and persistently normal ALT (PnALT) were matched 1:1 using propensity score matching. Correlations between plasma metabolites and the risk of elevated ALT were examined using multivariate logistic regression. A mouse model of carbon tetrachloride-induced liver injury was established to validate the effect of key differential metabolites on liver injury. Of the 1238 patients with CHB who achieved complete viral suppression, 40 (3.23%) had PeALT levels during follow-up (median follow-up: 2.42 years). Additionally, 40 patients with PnALT levels were matched as controls. Ser-Phe-Ala, Lys-Ala-Leu-Glu, 3-methylhippuric acid, 3-methylxanthine, and 7-methylxanthine were identified as critical differential metabolites between the two groups and independently associated with PeALT risk. Ser-Phe-Ala and Lys-Ala-Leu-Glu levels could be used to discriminate patients with PeALT from those with PnALT. Furthermore, N-acetyl- l-methionine (NALM) demonstrated the strongest negative correlation with ALT levels. NALM supplementation alleviated liver injury and hepatic necrosis induced by carbon tetrachloride in mice. Changes in circulating metabolites may contribute to PeALT levels in patients with CHB who have achieved complete viral suppression after antiviral treatment.

KLRG1-expressing CD8+ T cells are exhausted and polyfunctional in patients with chronic hepatitis B

Killer cell lectin-like receptor G1 (KLRG1) has traditionally been regarded as an inhibitory receptor of T cell exhaustion in chronic infection and inflammation. However, its exact role in hepatitis B virus (HBV) infection remains elusive. CD8+ T cells from 190 patients with chronic hepatitis B were analyzed ex vivo for checkpoint and apoptosis markers, transcription factors, cytokines and subtypes in 190 patients with chronic hepatitis B. KLRG1+ and KLRG1- CD8+ T cells were sorted for transcriptome analysis. The impact of the KLRG1-E-cadherin pathway on the suppression of HBV replication mediated by virus-specific T cells was validated in vitro. As expected, HBV-specific CD8+ T cells expressed higher levels of KLRG1 and showed an exhausted molecular phenotype and function. However, despite being enriched for the inhibitory molecules, thymocyte selection-associated high mobility group box protein (TOX), eomesodermin (EOMES), and Helios, CD8+ T cells expressing KLRG1 produced significant levels of tumour necrosis factor (TNF)-α, interferon (IFN)-γ, perforin, and granzyme B, demonstrating not exhausted but active function. Consistent with the in vitro phenotypic assay results, RNA sequencing (RNA-seq) data showed that signature effector T cell and exhausted T cell genes were enriched in KLRG1+ CD8+ T cells. Furthermore, in vitro testing confirmed that KLRG1-E-cadherin binding inhibits the antiviral efficacy of HBV-specific CD8+ T cells. Based on these findings, we concluded that KLRG1+ CD8+ T cells are not only a terminally exhausted subgroup but also exhibit functional diversity, despite inhibitory signs in HBV infection.

Activation of the cGAS-STING pathway by viral dsDNA leading to M1 polarization of macrophages mediates antiviral activity against hepatitis B virus

BACKGROUND AND AIMS

Activation of the cGAS-STING pathway induces the production of type I interferons, initiating the antiviral immune response, which contributes to the clearance of pathogens. Previous studies have shown that STING agonists promote hepatitis B virus (HBV) clearance; however, few studies have investigated the effect of activating the cGAS-STING pathway in macrophages on HBV.

METHODS

The polarization status of HBV particle-stimulated RAW264.7 macrophages was analyzed. After stimulation with HBV particles, the analysis focused on determining whether the DNA sensors in RAW264.7 macrophages recognized the viral double-stranded DNA (dsDNA) and evaluating the activation of the cGAS-STING pathway. Coculture of mouse macrophages and hepatocytes harboring HBV was used to study the antiviral activity of HBV-stimulated RAW264.7 macrophages.

RESULTS

After stimulation with HBV particles, HBV relaxed circular DNA (rcDNA) was detected in RAW264.7 macrophages, and the protein expression of phospho-STING, phospho-TBK1, and phospho-IRF3 in the STING pathway was increased, as shown by Western blot analysis, which revealed that M1 polarization of macrophages was caused by increased expression of CD86. RT-PCR analyses revealed elevated expression of M1 macrophage polarization-associated cytokines such as TNFα, IL-1β, iNOS, and IFNα/β. In the coculture experiment, both HBsAg and HBeAg expression levels were significantly decreased in AML12-HBV1.3 cells cocultured with the supernatants of HBV-stimulated RAW264.7 macrophages.

CONCLUSION

The results suggest that macrophages can endocytose HBV particles. Additionally, viral dsDNA can be recognized by DNA pattern recognition receptors, which in turn activate the cGAS-STING pathway, promoting the M1 polarization of macrophages, while no significant M2 polarization is observed. Macrophages stimulated with HBV particles exhibit enhanced antiviral activity against HBV.

Efficacy, safety, and pharmacokinetics of capsid assembly modulator linvencorvir plus standard of care in chronic hepatitis B patients

BACKGROUND/AIMS

Four-week treatment of linvencorvir (RO7049389) was generally safe and well tolerated, and showed anti-viral activity in chronic hepatitis B (CHB) patients. This study evaluated the efficacy, safety, and pharmacokinetics of 48-week treatment with linvencorvir plus standard of care (SoC) in CHB patients.

METHODS

This was a multicentre, non-randomized, non-controlled, open-label phase 2 study enrolling three cohorts: nucleos(t)ide analogue (NUC)-suppressed patients received linvencorvir plus NUC (Cohort A, n=32); treatment-naïve patients received linvencorvir plus NUC without (Cohort B, n=10) or with (Cohort C, n=30) pegylated interferon-α (Peg-IFN-α). Treatment duration was 48 weeks, followed by NUC alone for 24 weeks.

RESULTS

68 patients completed the study. No patient achieved functional cure (sustained HBsAg loss and unquantifiable HBV DNA). By Week 48, 89% of treatment-naïve patients (10/10 Cohort B; 24/28 Cohort C) reached unquantifiable HBV DNA. Unquantifiable HBV RNA was achieved in 92% of patients with quantifiable baseline HBV RNA (14/15 Cohort A, 8/8 Cohort B, 22/25 Cohort C) at Week 48 along with partially sustained HBV RNA responses in treatment-naïve patients during follow-up period. Pronounced reductions in HBeAg and HBcrAg were observed in treatment-naïve patients, while HBsAg decline was only observed in Cohort C. Most adverse events were grade 1-2, and no linvencorvir-related serious adverse events were reported.

CONCLUSION

48-week linvencorvir plus SoC was generally safe and well tolerated, and resulted in potent HBV DNA and RNA suppression. However, 48-week linvencorvir plus NUC with or without Peg-IFN did not result in the achievement of functional cure in any patient.

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.

The combination of Schisandrin C and Luteolin synergistically attenuates hepatitis B virus infection via repressing HBV replication and promoting cGAS-STING pathway activation in macrophages

BACKGROUND

HBV infection can result in severe liver diseases and is one of the primary causes of liver cell carcinoma-related mortality. Liuwei Wuling tablet (LWWL) is a traditional Chinese medicine formula, with a protecting liver and decreasing enzyme activity, usually used to treat chronic hepatitis B with NAs in clinic. However, its main active ingredients and mechanism of action have not been fully investigated. Hence, we aimed to screen the active ingredient and effective ingredient combinations from Liuwei Wuling tablet to explore the anti-herpatitis B virus activity and mechanism.

METHODS

Analysis and screening of effective antiviral components in LWWL by network pharmacology, luteolin (Lut) may be a compound with significant antiviral activity. The mechanism of antiviral action of Lut was also found by real-time PCR detection and western blotting. Meanwhile, we established a co-culture model to investigate the antiviral mechanism of Schisandrin C (SC), one of the main active components of Schisandra chinensis fructus (the sovereign drug of LWWL). Next, HBV-infected mice were established by tail vein injection of pAAV-HBV1.2 plasmid and administered continuously for 20 days. And their antiviral capacity was evaluated by checking serum levels of HBsAg, HBeAg, levels of HBV DNA, and liver levels of HBcAg.

RESULTS

In this study, we conducted network pharmacology analysis on LWWL, and through in vitro experimental validation and data analysis, we found that luteolin (Lut) possessed obviously anti-HBV activity, inhibiting HBV replication by downregulating hepatocyte nuclear factor 4α (HNF4α) via the ERK pathway. Additionally, we established a co-culture system and proved that SC promoted activation of cGAS-STINIG pathway and IFN-β production in THP-1 cells to inhibit HBV replication in HepG2.2.15 cells. Moreover, we found the combination of SC and Lut shows a greater effect in inhibiting HBV compared to SC or Lut alone in HBV-infected mice.

CONCLUSION

Taken together, our study suggests that combination of SC and Lut may be potential candidate drug for the prevention and treatment of chronic hepatitis B.

High normal alanine aminotransferase is an indicator for better response to antiviral therapy in chronic hepatitis B

Background

Evidence shows people living with CHB even with a normal ALT (40U/L as threshold) suffer histological disease and there is still little research to evaluate the potential benefit of antiviral benefits in them.

Methods

We retrospectively examined 1352 patients who underwent liver biopsy from 2017 to 2021 and then obtained their 1-year follow-up data to analyze.

Results

ALT levels were categorized into high and low, with thresholds set at >29 for males and >15 for females through Youden's Index. The high normal ALT group showed significant histological disease at baseline (56.43% vs 43.82%, p< 0.001), and better HBV DNA clearance from treatment using PSM (p=0.005). Similar results were obtained using 2016 AASLD high normals (male >30, female >19). Further multivariate logistic analysis showed that high normal ALT (both criterias) was an independent predictor of treatment (OR 1.993, 95% CI 1.115-3.560, p=0.020; OR 2.000, 95% CI 1.055-3.793, p=0.034) Both of the models had higher AUC compared with current scoring system, and there was no obvious difference between the two models (AUC:0.8840 vs 0.8835).

Conclusion

Male >30 or female >19 and Male >29 or female>15 are suggested to be better thresholds for normal ALT. Having a high normal ALT in CHB provides a potential benefit in antiviral therapy.

Recent progress on the application of compound formulas of traditional Chinese medicine in clinical trials and basic research in vivo for chronic liver disease

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic liver diseases mainly include chronic viral liver disease, metabolic liver disease, cholestatic liver disease (CLD), autoimmune liver disease, and liver fibrosis or cirrhosis. Notably, the compound formulas of traditional Chinese medicine (TCM) is effective for chronic liver diseases in clinical trials and basic research in vivo, which provide evidence of chronic liver disease treatment with integrated TCM and traditional Western medicine.

AIM OF THE REVIEW

This paper aims to provide a comprehensive review of the compound formulas of TCM for treating different chronic liver diseases to elucidate the composition, main curative effects, and mechanisms of these formulas and research methods.

MATERIALS AND METHODS

Different keywords related to chronic liver diseases and keywords related to the compound formulas of TCM were used to search the literature. PubMed, Scopus, Web of Science, and CNKI were searched to screen out original articles about the compound formulas of TCM related to the treatment of chronic liver diseases, mainly including clinical trials and basic in vivo research related to Chinese patent drugs, classic prescriptions, proven prescriptions, and hospital preparations. We excluded review articles, meta-analysis articles, in vitro experiments, articles about TCM monomers, articles about single-medicine extracts, and articles with incomplete or uncertain description of prescription composition. Plant names were checked with MPNS (http://mpns.kew.org).

RESULTS

In this review, the clinical efficacy and mechanism of compound formulas of TCM were summarized for the treatment of chronic viral hepatitis, nonalcoholic fatty liver disease, CLD, and liver fibrosis or cirrhosis developed from these diseases and other chronic liver diseases. For each clinical trial and basic research in vivo, this review provides a detailed record of the specific composition of the compound formulas of TCM, type of clinical research, modeling method of animal experiments, grouping methods, medication administration, main efficacy, and mechanisms.

CONCLUSION

The general development process of chronic liver disease can be summarized as chronic hepatitis, liver fibrosis or cirrhosis, and hepatocellular carcinoma. The compound formulas of TCM have some applications in these stages of chronic liver diseases. Owing to the continuous progress of medical technology, the benefits of the compound formulas of TCM in the treatment of chronic liver diseases are constantly changing and developing.

The potential of IFN-λ, IL-32γ, IL-6, and IL-22 as safeguards against human viruses: a systematic review and a meta-analysis

Many studies have investigated the antiviral activity of cytokines, including interleukin-6 (IL-6), interleukin-22 (IL-22), interleukin-32 gamma (IL-32γ), and interferon-lambda (IFN-λ) in diverse populations. This study aims to evaluate the role of these cytokines in inhibition of various human and animal viruses when administered exogenously. A comprehensive meta-analysis and systematic review were conducted on all the relevant studies from three databases. Standard mean differences (SMDs) of overall viral inhibition were used to generate the difference in the antiviral efficacy of these cytokines between control and experimental groups. A total of 4,618 abstracts for IL-6, 3,517 abstracts for IL-22, 2,160 abstracts for IL-32γ, and 1,026 abstracts for IFN-λ were identified, and 7, 4, 8, and 35 studies were included, respectively, for each cytokine. IFN-λ (SMD = 0.9540; 95% CI: 0.69-0.22) and IL-32γ (SMD = 0.459; 95% CI: 0.02-0.90) showed the highest influence followed by IL-6 (SMD = 0.456; CI: -0.04-0.95) and IL-22 (SMD = 0.244; 95% CI: -0.33-0.81). None of the cytokines represented heterogeneity (tau² > 0), but only IFN-λ indicated the funnel plot asymmetry (p = 0.0097). Results also indicated that IFN-λ and IL-32γ are more potent antivirals than IL-6 and IL-22. The collective findings of this study emphasize that exogenously administered pro-inflammatory cytokines, specifically IFN-λ and IL-32, exhibit a significant antiviral activity, thereby underscoring them as potent antiviral agents. Nonetheless, additional research is required to ascertain their clinical utility and potential for integration into combinatorial therapeutic regimens against viral infections.

MDSC-targeted liposomal all-trans retinoic acid suppresses mMdscs and improves immunotherapy in HBV infection

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are evolving as a prominent determinant in cancer occurrence and development and are functionally found to suppress T cells in cancer. Not much research is done regarding its involvement in viral infections. This research was designed to investigate the role of MDSCs in hepatitis B virus (HBV) infection and how targeting these cells with our novel all-trans retinoic acid encapsulated liposomal formulation could improve immunotherapy in C57BL/6 mice.

METHODS

Ten micrograms (10 μg) of plasmid adeno-associated virus (pAAV/HBV 1.2, genotype A) was injected hydrodynamically via the tail vein of C57BL/6 mice. An all-trans retinoic acid encapsulated liposomal formulation (L-ATRA) with sustained release properties was used in combination with tenofovir disoproxil fumarate (TDF), a nucleotide analog reverse transcriptase inhibitor (nRTI) to treat the HBV infection. The L-ATRA formulation was given at a dose of 5 mg/kg intravenously (IV) twice a week. The TDF was given orally at 30 mg/kg daily.

RESULTS

Our results revealed that L-ATRA suppresses MDSCs in HBV infected mice and enhanced T-cell proliferation in vitro. In vivo studies showed higher and improved immunotherapeutic effect in mice that received L-ATRA and TDF concurrently in comparison with the groups that received monotherapy. Lower HBV DNA copies, lower concentrations of HBsAg and HBeAg, lower levels of ALT and AST and less liver damage were seen in the mice that received the combination therapy of L-ATRA + TDF.

CONCLUSIONS

In effect, targeting MDSCs with the combination of L-ATRA and TDF effectively reduced mMDSC and improved immunotherapy in the HBV infected mice. Targeting MDSCs could provide a breakthrough in the fight against hepatitis B virus infection.

Phosphorylation of RGS16 at Tyr168 promote HBeAg-mediated macrophage activation by ERK pathway to accelerate liver injury

Liver injury is closely associated with macrophage activation following HBV infection. Our previous study showed that only HBeAg, but not HBsAg and HBcAg, stably enhances inflammatory cytokine production in macrophages. And we also indicated that HBeAg could induce macrophage activation via TLR2 and thus aggravate the progression of liver fibrosis. However, the specific molecular mechanism of HBeAg in macrophage activation is not clear. We screened significantly overexpressed RGS16 from RNASeq results of HBeAg-stimulated macrophages and validated them with cellular assays, GSE83148 microarray dataset, and in clinical samples. Meanwhile, small interference, plasmid, and lentivirus transfection assays were used to establish cell models for knockdown and overexpression of RGS16, and q-PCR, ELISA, Transwell, and CCK-8 assays were used to analyze the role of RGS16 in HBeAg-induced macrophage activation. In addition, the upstream and downstream mechanisms of RGS16 in HBeAg-treated macrophage activation were explored using inhibitors, phostag gels, and RGS16 phosphorylation mutant plasmids. Finally, the effect of RGS16 on hepatic inflammation in murine tissues was evaluated by H&E staining, liver enzyme assay and immunofluorescence. RGS16 was significantly upregulated in HBeAg-induced macrophage activation, and its expression was enhanced with increasing HBeAg content and treatment time. Functional experiments showed that overexpression of RGS16 promoted the production of inflammatory factors TNF-α and IL-6 and boosted macrophage proliferation and migration, while knockdown of RGS16 exhibited the opposite effect. Mechanistically, we discovered that RGS16 is regulated by the TLR2/P38/STAT5 signaling pathway. Meanwhile, RGS16 enhanced ERK phosphorylation via its own Tyr168 phosphorylation to contribute to macrophage activation, thereby accelerating liver injury. Finally, in mice, overexpression of RGS16 markedly strengthened liver inflammation. HBeAg upregulates RGS16 expression through the TLR2-P38-STAT5 axis, and the upregulated expression of RGS16 enhances macrophage activation and accelerates liver injury by promoting ERK phosphorylation. In this process, phosphorylation of Tyr168 is necessary for RGS16 to function. KEY MESSAGES: RGS16 boosted HBeAg-induced macrophage inflammation, proliferation, and migration. Tyr168 phosphorylation of RGS16 affected by ERK promoted macrophage activation. HBeAg upregulated the expression of RGS16 through TLR2/P38/STAT5 signal pathway. RGS16 promoted liver injury by regulating macrophage functions in mouse model.

The potential effect of HBV vaccination on off-treatment HBsAg reversion after interferon-induced HBsAg clearance

Off-treatment HBsAg reversion occurs in a considerable number of chronic hepatitis B(CHB) patients after IFN(interferon)-induced HBsAg clearance. HBV vaccination protects the general population against HBV infection. However, it remains unclear whether HBV vaccination could prevent off-treatment HBsAg reversion in CHB patients with HBsAg clearance. CHB patients (n = 199) with HBsAg clearance were included in the current study, comprising spontaneous HBsAg clearance group (n = 51), NA (nucleoside/nucleotide analogues)-induced group (n = 36) and IFN-induced group (n = 112). Log-rank test was performed to compare the cumulative incidences of HBsAg reversion between groups. Cox regression model was used to identify the factors associated with off-treatment HBsAg reversion. The 5-year cumulative incidence of HBsAg reversion in IFN-induced group was significantly higher than that in NA-induced group or spontaneous group (27.6% vs. 3.3% vs. 8.1%, both p < .05). In IFN-induced group, 66.7% of CHB patients received HBV vaccination. The cumulative incidence of HBsAg reversion in individuals with strong responses to HBV vaccination (HBsAb level >100mIU/ml) was significantly lower than that in those with weak responses to HBV vaccination (HBsAb level ≤100mIU/ml) or without HBV vaccination in IFN-induced group (7.7% vs. 58.5% vs. 31.9%, both p < .05). Multivariate Cox regression analysis confirmed strong responses to HBV vaccination were independently associated with a lower cumulative incidence of HBsAg reversion after IFN-induced HBsAg clearance (HR = 0.246, 95%CI: 0.066-0.907, p = .035). HBV vaccination has potential to prevent off-treatment HBsAg reversion in CHB patients after IFN-induced HBsAg clearance via a sufficiently high level of HBsAb, helping clinicians optimize the clinical management of such patients.

A novel TRIM22 gene polymorphism promotes the response to PegIFNα therapy through cytokine-cytokine receptor interaction signaling pathway in chronic hepatitis B

IMPORTANCE

Pegylated interferon alfa (PegIFNα) has limited efficacy in the treatment of chronic hepatitis B (CHB). Although many biomarkers related to hepatitis B virus (HBV) have been proposed to stratify patients, the response rate to PegIFNα is still unsatisfactory. Herein, our data suggest that the single-nucleotide polymorphism (SNP) rs10838543 in TRIM22 potentiates a positive clinical response to PegIFNα treatment in patients with hepatitis B e antigen-positive CHB by increasing the levels of IFNL1, CCL3, and CCL5. These observations can help guide treatment decisions for patients with CHB to improve the response rate to PegIFNα.

Epstein-Barr virus reactivation correlates with worse outcomes for patients exposed to hepatitis B virus after haploidentical hematopoietic stem cell transplantation

Hepatitis B virus (HBV)has a high, chronic infection rate in Asian populations, but only few studies have analyzed the effect of Epstein-Barr virus (EBV) or Cytomegalovirus (CMV) reactivation in patients exposed to HBV after haploidentical hematopoietic stem cell transplantation (haplo-HSCT). This study aimed to assess the clinical outcomes of these patients. We conducted a retrospective research including 61 patients exposed to HBV after undergoing haplo-HSCT. The patients were classified into two groups: the CMV reactivation group and no CMV reactivation group. The results were compared between the two groups using the K-W test for continuous variables, Pearson's chi-square test for categorical variables, Kaplan-Meier curves to estimate overall survival (OS) and leukemia-free survival (LFS), and a Cox proportional hazards model to analyze multivariable influences. The 3-year cumulative HBV reactivation rate was 8.2%. The median duration of HBV reactivation was 16 months (16-22 months) after haplo-HSCT. The CMV reactivation group had a higher cumulative incidence of HBV reactivation than the group without CMV reactivation. The EBV reactivation was substantially higher in the CMV reactivation group compared to that in the no CMV reactivation group (37.0% vs.5.9% respectively; P = 0.002). Furthermore, EBV reactivation was a risk factor for 1-year LFS and 1-year OS. Based on our data, EBV reactivation was related to worse outcomes in patients exposed to HBV after haplo-HSCT, whereas CMV reactivation was not.

IL-2 produced by HBV-specific T cells as a biomarker of viral control and predictor of response to PD-1 therapy across clinical phases of chronic hepatitis B

BACKGROUND

There are no immunological biomarkers that predict control of chronic hepatitis B (CHB). The lack of immune biomarkers raises concerns for therapies targeting PD-1/PD-L1 because they have the potential for immune-related adverse events. Defining specific immune functions associated with control of HBV replication could identify patients likely to respond to anti-PD-1/PD-L1 therapies and achieve a durable functional cure.

METHODS

We enrolled immunotolerant, HBeAg+ immune-active (IA+), HBeAg- immune-active (IA-), inactive carriers, and functionally cured patients to test ex vivo PD-1 blockade on HBV-specific T cell functionality. Peripheral blood mononuclear cells were stimulated with overlapping peptides covering HBV proteins +/-α-PD-1 blockade. Functional T cells were measured using a 2-color FluoroSpot assay for interferon-γ and IL-2. Ex vivo functional restoration was compared to the interferon response capacity assay, which predicts overall survival in cancer patients receiving checkpoint inhibitors.

RESULTS

Ex vivo interferon-γ+ responses did not differ across clinical phases. IL-2+ responses were significantly higher in patients with better viral control and preferentially restored with PD-1 blockade. Inactive carrier patients displayed the greatest increase in IL-2 production, which was dominated by CD4 T cell and response to the HBcAg. The interferon response capacity assay significantly correlated with the degree of HBV-specific T cell restoration.

CONCLUSIONS

IL-2 production was associated with better HBV control and superior to interferon-γ as a marker of T cell restoration following ex vivo PD-1 blockade. Our study suggests that responsiveness to ex vivo PD-1 blockade, or the interferon response capacity assay, may support stratification for α-PD-1 therapies.

Patient acceptability of, and attitudes towards, hepatitis B cure research - A scoping review and identification of knowledge gaps

Functional cure, defined as durable loss of hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) DNA suppression off therapy, is an increasingly important goal in the treatment of chronic hepatitis B. Although novel treatments aimed at achieving functional cure are being developed and tested in clinical trials, it is important to assess the perspectives of people living with HBV towards these potential treatments and their participation in HBV functional cure research. We have performed a scoping review that revealed that there is limited knowledge regarding patient perspectives of HBV functional cure research and then identified gaps in knowledge for further investigation. Our work highlights the need for further studies in patient perspectives in HBV functional cure research.

Advances in Cancer Vaccine Research

The use of cancer vaccines is considered a promising therapeutic strategy in clinical oncology, which is achieved by stimulating antitumor immunity with tumor antigens delivered in the form of cells, peptides, viruses, and nucleic acids. The ideal cancer vaccine has many advantages, including low toxicity, specificity, and induction of persistent immune memory to overcome tumor heterogeneity and reverse the immunosuppressive microenvironment. Many therapeutic vaccines have entered clinical trials for a variety of cancers, including melanoma, breast cancer, lung cancer, and others. However, many challenges, including single antigen targeting, weak immunogenicity, off-target effects, and impaired immune response, have hindered their broad clinical translation. In this review, we introduce the principle of action, components (including antigens and adjuvants), and classification (according to applicable objects and preparation methods) of cancer vaccines, summarize the delivery methods of cancer vaccines, and review the clinical and theoretical research progress of cancer vaccines. We also present new insights into cancer vaccine technologies, platforms, and applications as well as an understanding of potential next-generation preventive and therapeutic vaccine technologies, providing a broader perspective for future vaccine design.

Editorial: Time to consider early treatment for chronic hepatitis B in both children and adults-authors' reply

This article is linked to Wu et al papers. To view these articles, visit https://doi.org/10.1111/apt.17667 and https://doi.org/10.1111/apt.17679

Alzheimer's disease as a viral disease: Revisiting the infectious hypothesis

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. Two major forms of the disease exist: sporadic - the causes of which have not yet been fully understood - and familial - inherited within families from generation to generation, with a clear autosomal dominant transmission of mutations in Presenilin 1 (PSEN1), 2 (PSEN2) or Amyloid Precursors Protein (APP) genes. The main hallmark of AD consists of extracellular deposits of amyloid-beta (Aβ) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein. An ever-growing body of research supports the viral infectious hypothesis of sporadic forms of AD. In particular, it has been shown that several herpes viruses (i.e., HHV-1, HHV-2, HHV-3 or varicella zoster virus, HHV-4 or Epstein Barr virus, HHV-5 or cytomegalovirus, HHV-6A and B, HHV-7), flaviviruses (i.e., Zika virus, Dengue fever virus, Japanese encephalitis virus) as well as Human Immunodeficiency Virus (HIV), hepatitis viruses (HAV, HBV, HCV, HDV, HEV), SARS-CoV2, Ljungan virus (LV), Influenza A virus and Borna disease virus, could increase the risk of AD. Here, we summarized and discussed these results. Based on these findings, significant issues for future studies are also put forward.

Test All for Hepatitis B Virus: Link to Care and Treatment if Quantitative DNA Positive, Vaccinate if Susceptible

Hepatitis B infection affects approximately 262 million people worldwide and is responsible for 900,000 deaths annually. This article reviews the major factors limiting HBV elimination, which includes limited linkage to care and complicated HBV testing and treatment guidelines. The article then provides solutions to these pressing issues.

Oncostatin M Induces IFITM1 Expression to Inhibit Hepatitis B Virus Replication Via JAK-STAT Signaling

BACKGROUND & AIMS

Functional cure is achieved by a limited number of patients with chronic hepatitis B (CHB) after nucleotide analogue(s) and interferon treatment. It is urgent to develop therapies that can help a larger proportion of patients achieve functional cure. The present study was designed to explore the anti-hepatitis B virus (HBV) potency of interleukin-6 family cytokines and to characterize the underlying mechanisms of the cytokine displaying the highest anti-HBV potency.

METHODS

HBV-infected cells were used to screened the anti-HBV potency of interleukin-6 family cytokines. The concentration of oncostatin M (OSM) in patients with chronic HBV infection was examined by enzyme-linked immunosorbent assay. The underlying mechanism of OSM anti-HBV was explored through RNA-seq. C57BL/6 mice injected with rAAV8-1.3HBV were used to explore the suppression effect of OSM on HBV in vivo.

RESULTS

OSM is the most effective of the interleukin-6 family cytokines for suppression of HBV replication (percentage of average inhibition: hepatitis B surface antigen, 34.44%; hepatitis B e antigen, 32.52%; HBV DNA, 61.57%). Hepatitis B e antigen-positive CHB patients with high OSM levels had lower hepatitis B surface antigen and hepatitis B e antigen than those with low levels. OSM activated JAK-STAT signaling pathway promoting the formation of STAT1-IRF9 transcription factor complex. Following this, OSM increased the expression of various genes with known functions in innate and adaptive immunity, which was higher expression in patients with CHB in immune clearance phase than in immune tolerance phase (data from GEO: GSE65359). Interferon-induced transmembrane protein 1, one of the most differentially expressed genes, was identified as an HBV restriction factor involved in OSM-mediated anti-HBV effect. In vivo, we also found OSM significantly inhibited HBV replication and induced expression of antiviral effector interferon-induced transmembrane protein 1.

CONCLUSIONS

Our study shows that OSM remodels the immune response against HBV and exerts potent anti-HBV activity, supporting its further development as a potential therapy for treating CHB.

Metabolic interventions improve HBV envelope-specific T-cell responses in patients with chronic hepatitis B

BACKGROUND

Restoration of HBV-specific T cell immunity is a promising approach for the functional cure of chronic Hepatitis B (CHB), necessitating the development of valid assays to boost and monitor HBV-specific T cell responses in patients with CHB.

METHODS

We analyzed hepatitis B virus (HBV) core- and envelope (env)-specific T cell responses using in vitro expanded peripheral blood mononuclear cells (PBMCs) from patients with CHB exhibiting different immunological phases, including immune tolerance (IT), immune activation (IA), inactive carrier (IC), and HBeAg-negative hepatitis (ENEG). Additionally, we evaluated the effects of metabolic interventions, including mitochondria-targeted antioxidants (MTA), polyphenolic compounds, and ACAT inhibitors (iACAT), on HBV-specific T-cell functionality.

RESULTS

We found that HBV core- and env-specific T cell responses were finely coordinated and more profound in IC and ENEG than in the IT and IA stages. HBV env-specific T cells were more dysfunctional but prone to respond to metabolic interventions using MTA, iACAT, and polyphenolic compounds than HBV core-specific T-cells. The responsiveness of HBV env-specific T cells to metabolic interventions can be predicted by the eosinophil (EO) count and the coefficient of variation of red blood cell distribution width (RDW-CV).

CONCLUSION

These findings may provide valuable information for metabolically invigorating HBV-specific T-cells to treat CHB.

Insights into the mechanisms of telbivudine-induced myopathy associated with mitochondrial dysfunction

As a nucleotide analogue (NA), telbivudine was widely used in the treatment for chronic hepatitis B (CHB) by interfering with reverse transcriptase of hepatitis B virus. However, the use of NAs for hepatitis B treatment has been accompanied by numerous reports highlighting the occurrence of neuromyopathy, particularly in the case of telbivudine. This study aimed to investigate the underlying mechanisms responsible for telbivudine-induced myopathy. We established animal and cell models of telbivudine-induced myopathy using C57BL/6 mice and C2C12 cells, respectively. Our findings revealed that telbivudine significantly reduced mitochondrial DNA (mtDNA) copy number and caused increase of oxidative stress. Telbivudine treatment significantly inhibited mitochondrial complex I and IV expression, impairing the oxidative phosphorylation function of the respiratory chain. Modified Gomori trichrome (MGT) staining of the muscle sections displayed an increase in ragged red fibers (RRFs), indicating abnormal mitochondrial accumulation. In conclusion, our study provides compelling evidence suggesting that telbivudine-induced myopathy is associated with mitochondrial toxicity and impaired energy metabolism. The observed muscle pathology, depletion of mtDNA, elevation of oxidative stress and altered mitochondrial function support the hypothesis that telbivudine disrupts mitochondrial homeostasis, ultimately leading to muscle damage. This may be also a common mechanism for NAs to cause neuromyopathy.

Efficacy of antiviral therapy and host-virus interactions visualised using serial liver sampling with fine-needle aspirates

Background & Aims

Novel therapies for chronic hepatitis B (CHB), such as RNA interference, target all viral RNAs for degradation, whereas nucleoside analogues are thought to block reverse transcription with minimal impact on viral transcripts. However, limitations in technology and sampling frequency have been obstacles to measuring actual changes in HBV transcription in the liver of patients starting therapy.

Methods

We used elective liver sampling with fine-needle aspirates (FNAs) to investigate the impact of treatment on viral replication in patients with CHB. Liver FNAs were collected from patients with CHB at baseline and 12 and 24 weeks after starting tenofovir alafenamide treatment. Liver FNAs were subjected to single-cell RNA sequencing and analysed using the Viral-Track method.

Results

HBV was the only viral genome detected and was enriched within hepatocytes. The 5' sequencing technology identified protein-specific HBV transcripts and showed that tenofovir alafenamide therapy specifically reduced pre-genomic RNA transcripts with little impact on HBsAg or HBx transcripts. Infected hepatocytes displayed unique gene signatures associated with an immunological response to viral infection.

Conclusions

Longitudinal liver sampling, combined with single-cell RNA sequencing, captured the dynamic impact of antiviral therapy on the replication status of HBV and revealed host-pathogen interactions at the transcriptional level in infected hepatocytes. This sequencing-based approach is applicable to early-stage clinical studies, enabling mechanistic studies of immunopathology and the effect of novel therapeutic interventions.

Impact and Implications

Infection-dependent transcriptional changes and the impact of antiviral therapy on viral replication can be measured in longitudinal human liver biopsies using single-cell RNA sequencing data.

Liver Cell Type-Specific Targeting by Nanoformulations for Therapeutic Applications

Hepatocytes exert pivotal roles in metabolism, protein synthesis and detoxification. Non-parenchymal liver cells (NPCs), largely comprising macrophages, dendritic cells, hepatic stellate cells and liver sinusoidal cells (LSECs), serve to induce immunological tolerance. Therefore, the liver is an important target for therapeutic approaches, in case of both (inflammatory) metabolic diseases and immunological disorders. This review aims to summarize current preclinical nanodrug-based approaches for the treatment of liver disorders. So far, nano-vaccines that aim to induce hepatitis virus-specific immune responses and nanoformulated adjuvants to overcome the default tolerogenic state of liver NPCs for the treatment of chronic hepatitis have been tested. Moreover, liver cancer may be treated using nanodrugs which specifically target and kill tumor cells. Alternatively, nanodrugs may target and reprogram or deplete immunosuppressive cells of the tumor microenvironment, such as tumor-associated macrophages. Here, combination therapies have been demonstrated to yield synergistic effects. In the case of autoimmune hepatitis and other inflammatory liver diseases, anti-inflammatory agents can be encapsulated into nanoparticles to dampen inflammatory processes specifically in the liver. Finally, the tolerance-promoting activity especially of LSECs has been exploited to induce antigen-specific tolerance for the treatment of allergic and autoimmune diseases.

A role for immune modulation in achieving functional cure for chronic hepatitis B among current changes in the landscape of new treatments

INTRODUCTION

Chronic hepatitis B (CHB) is rarely cured using available treatments. Barriers to cure are: 1) persistence of reservoirs of hepatitis B virus (HBV) replication and antigen production (HBV DNA); 2) high burden of viral antigens that promote T cell exhaustion with T cell dysfunction; 3) CHB-induced impairment of immune responses.

AREAS COVERED

We discuss options for new therapies that could address one or more of the barriers to functional cure, with particular emphasis on the potential role of immunotherapy.

EXPERT OPINION/COMMENTARY

Ideally, a sterilizing cure for CHB would translate into finite therapies that result in loss of HBV surface antigen and eradication of HBV DNA. Restoration of a functional adaptive immune response, a key facet of successful CHB treatment, remains elusive. Numerous strategies targeting the high viral DNA and antigen burden and aiming to restore the host immune responses will enter clinical development in coming years. Most patients are likely to require combinations of several drugs, personalized according to virologic and disease characteristics, patient preference, accessibility, and affordability. The management of CHB is a global health priority. Expedited drug development requires collaborations between regulatory agencies, scientists, clinicians, and within the industry to facilitate testing of the best drug combinations.

The potential of epigallocatechin gallate in the chemoprevention and therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most notorious malignancies globally, has a high fatality and poor prognosis. Though remarkable breakthroughs have been made in the therapeutic strategies recently, the overall survival of HCC remains unsatisfactory. Consequently, the therapy of HCC remains a great challenge. Epigallocatechin gallate (EGCG), a natural polyphenol extracted from the leaves of the tea bush, has been extensively investigated for its antitumor effects. In this review, we summarize the previous literature to elucidate the roles of EGCG in the chemoprophylaxis and therapy of HCC. Accumulating evidence has confirmed EGCG prevents and inhibits the hepatic tumorigenesis and progression through multiple biological mechanisms, mainly involving hepatitis virus infection, oxidative stress, proliferation, invasion, migration, angiogenesis, apoptosis, autophagy, and tumor metabolism. Furthermore, EGCG enhances the efficacy and sensitivity of chemotherapy, radiotherapy, and targeted therapy in HCC. In conclusion, preclinical studies have confirmed the potential of EGCG for chemoprevention and therapy of HCC under multifarious experimental models and conditions. Nevertheless, there is an urgent need to explore the safety and efficacy of EGCG in the clinical practice of HCC.

A prodrug of the capsid assembly modulator improved druggability and lowing HBsAg and HBeAg for the treatment of chronic hepatitis B

CAMs were disclosed to alter cccDNA levels with sustained hepatitis B surface antigen (HBsAg) loss or seroconversion in preclinical investigation. Here, we report the discovery of a prodrug Yhhu6669 as CAMs based on the intestinal peptide transporter. This compound exhibited the promising anti-HBV activity with sustained suppression of HBV DNA, as well as HBsAg and HBeAg in the AAV HBV mouse model by oral treatment for 7 weeks and maintained for a further 8 weeks following drug withdraw. Our results show an alternative possibility for a functional cure by specific CAMs and provide the basis for the further mechanism study.

Developments in pharmacotherapeutic agents for hepatitis B - how close are we to a functional cure?

INTRODUCTION

Hepatitis B virus (HBV) remains a public health concern given its global prevalence and potential complications including hepatocellular carcinoma (HCC). Current therapies, including nucleos(t)ide analogs (NA) and interferons (IFN), are effective in chronic treatment of HBV but rarely provide a functional cure due to inadequate host response and the presence of viral DNA. Therefore, novel therapies that enhance the innate immune response while suppressing DNA transcription may provide definitive treatment of HBV.

AREAS COVERED

In this review, the authors provide a brief overview of commonly used agents and their efficacy in treatment of HBV. Newer therapies with direct antiviral agents such as bepirovirsen (antisense oligonucleotide (ASO)) and entry inhibitors such as bulevirtide have shown efficacy in reducing viral load but demonstrate further reductions in conjunction with immune modulators such as therapeutic vaccines.

EXPERT OPINION

Combination therapy is far superior to monotherapy alone, necessitating the need for both immunomodulators and direct antiviral agents in chronic treatment of HBV. Therapies that target covalently closed circular (cccDNA) with immunomodulators like therapeutic vaccines have shown promising results and may ultimately achieve functional cure. However, therapies need to be evaluated in the context of the patient, considering both financial and socioeconomic factors.

Forthcoming Developments in Models to Study the Hepatitis B Virus Replication Cycle, Pathogenesis, and Pharmacological Advancements

Hepatitis, liver cirrhosis, and hepatocellular carcinoma are all manifestations of chronic hepatitis B. Its pathogenesis and molecular mechanism remain mysterious. As medical science progresses, different models are being used to study the disease from the physiological and molecular levels. Animal models have played an unprecedented role in achieving in-depth knowledge of the disease while posing no risk of harming humans throughout the study. The scarcity of acceptable animal models has slowed progress in hepatitis B virus (HBV) research and preclinical testing of antiviral medicines since HBV has a narrow species tropism and exclusively infects humans and higher primates. The development of human chimeric mice was supported by a better understanding of the obstacles to interspecies transmission, which has substantially opened the way for HBV research in vivo and the evaluation of possible chronic hepatitis B therapeutics. Animal models are cumbersome to handle, not accessible, and expensive. Hence, it is herculean to investigate the HBV replication cycle in animal models. Therefore, it becomes essential to build a splendid in vitro cell culture system to demonstrate the mechanisms attained by the HBV for its multiplication and sustenance. We also addressed the advantages and caveats associated with different models in examining HBV.

HBV Infection and Host Interactions: The Role in Viral Persistence and Oncogenesis

Hepatitis B virus (HBV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Despite the advent of vaccines and potent antiviral agents able to suppress viral replication, recovery from chronic HBV infection is still an extremely difficult goal to achieve. Complex interactions between virus and host are responsible for HBV persistence and the risk of oncogenesis. Through multiple pathways, HBV is able to silence both innate and adaptive immunological responses and become out of control. Furthermore, the integration of the viral genome into that of the host and the production of covalently closed circular DNA (cccDNA) represent reservoirs of viral persistence and account for the difficult eradication of the infection. An adequate knowledge of the virus-host interaction mechanisms responsible for viral persistence and the risk of hepatocarcinogenesis is necessary for the development of functional cures for chronic HBV infection. The purpose of this review is, therefore, to analyze how interactions between HBV and host concur in the mechanisms of infection, persistence, and oncogenesis and what are the implications and the therapeutic perspectives that follow.

Insights into the impact of hepatitis B virus on hepatic stellate cell activation

During chronic hepatitis B virus (HBV) infection, hepatic fibrosis is a serious pathological condition caused by virus-induced liver damage. The activation of hepatic stellate cells (HSCs) is a central event in the occurrence and progression of liver fibrosis. Although accumulating evidence has shown that HBV directly stimulates HSC activation, whether the virus infects and replicates in HSCs remains controversial. Inflammation is one of the obvious characteristics of chronic HBV infection, and it has been demonstrated that persistent inflammation has a predominant role in triggering and maintaining liver fibrosis. In particular, the regulation of HSC activation by HBV-related hepatocytes via various inflammatory modulators, including TGF-β and CTGF, in a paracrine manner has been reported. In addition to these inflammation-related molecules, several inflammatory cells are essential for the progression of HBV-associated liver fibrosis. Monocytes, macrophages, Th17 cells, NK cells, as well as NKT cells, participate in the modulation of HBV-related liver fibrosis by interacting with HSCs. This review summarizes current findings on the effects of HBV and the relevant molecular mechanisms involved in HSC activation. Because HSC activation is essential for liver fibrosis, targeting HSCs is an attractive therapeutic strategy to prevent and reverse hepatic fibrosis induced by HBV infection. Video abstract.

What will it take to cure hepatitis B?

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

Immune checkpoints on T and NK cells in the context of HBV infection: Landscape, pathophysiology and therapeutic exploitation

In hepatitis B virus (HBV) infection, the interplay between the virus and the host immune system is crucial in determining the pathogenesis of the disease. Patients who fail to mount a sufficient and sustained anti-viral immune response develop chronic hepatitis B (CHB). T cells and natural killer (NK) cells play decisive role in viral clearance, but they are defective in chronic HBV infection. The activation of immune cells is tightly controlled by a combination of activating and inhibitory receptors, called immune checkpoints (ICs), allowing the maintenance of immune homeostasis. Chronic exposure to viral antigens and the subsequent dysregulation of ICs actively contribute to the exhaustion of effector cells and viral persistence. The present review aims to summarize the function of various ICs and their expression in T lymphocytes and NK cells in the course of HBV infection as well as the use of immunotherapeutic strategies targeting ICs in chronic HBV infection.

LAMP3 expression in the liver is involved in T cell activation and adaptive immune regulation in hepatitis B virus infection

Background

The disease burden caused by chronic hepatitis B virus (HBV) infection is still heavy, and the current treatment scheme has not achieved a complete cure. Changes in natural and adaptive immunity usually accompany chronic HBV infection. As a marker expressed on dendritic cells (DCs), whether lysosome-associated membrane glycoprotein 3 (LAMP3) participates in chronic HBV infection deserves further analysis.

Methods

We retrieved chronic HBV infection transcriptional information from the Gene Expression Omnibus (GEO) database. The LAMP3 expression in the liver of patients with chronic hepatitis B (CHB) was analyzed in three GEO datasets and confirmed in our validation cohort (27 patients with CHB). Differentially expressed genes were obtained from one CHB cohort by comparing LAMP3high and LAMP3low expression subgroups. These genes underwent Gene Ontology, Kyoto Encyclopedia of Genes and Genomes analysis, and Gene Set Enrichment Analysis to decipher the influence of LAMP3 on the biological process and immunity changes in HBV infection. Furthermore, we investigated the potential relationship between LAMP3 levels, the abundance of infiltrating immune cells, and liver dysfunction.

Results

Compared to healthy controls, LAMP3 expression was upregulated in the transcriptional profiles of the liver in patients with CHB. The high LAMP3 expression was related to T cell activation and the chemokine signaling pathway. The LAMP3 gene was positively linked to marker sets of infiltrating activated regulatory T cells (Treg), T cell exhaustion, monocytes, and DCs. Moreover, CHB patients with high LAMP3 expression had unfavorable liver dysfunction.

Conclusions

LAMP3 is a gene related to HBV infection, which might be involved in HBV infection by regulating T cell activation and adaptive immune response.

An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.