Therapeutic strategies for hepatitis B virus infection: towards a cure

Engineered extracellular vesicles for delivering functional Cas9/gRNA to eliminate hepatitis B virus cccDNA and integration

The persistence of HBV covalently closed circular DNA (cccDNA) and HBV integration into the host genome in infected hepatocytes pose significant challenges to the cure of chronic HBV infection. Although CRISPR/Cas9-mediated genome editing shows promise for targeted clearance of viral genomes, a safe and efficient delivery method is currently lacking. Here, we developed a novel approach by combining light-induced heterodimerization and protein acylation to enhance the loading efficiency of Cas9 protein into extracellular vesicles (EVs). Moreover, vesicular stomatitis virus-glycoprotein (VSV-G) was incorporated onto the EVs membrane, significantly facilitating the endosomal escape of Cas9 protein and increasing its gene editing activity in recipient cells. Our results demonstrated that engineered EVs containing Cas9/gRNA and VSV-G can effectively reduce viral antigens and cccDNA levels in the HBV-replicating and infected cell models. Notably, we also confirmed the antiviral activity and high safety of the engineered EVs in the HBV-replicating mouse model generated by hydrodynamic injection and the HBV transgenic mouse model. In conclusion, engineered EVs could successfully mediate functional CRISPR/Cas9 delivery both in vitro and in vivo, leading to the clearance of episomal cccDNA and integrated viral DNA fragments, and providing a novel therapeutic approach for curing chronic HBV infection.

An extracellular humanized IFNAR immunocompetent mouse model for analyses of human interferon alpha and subtypes

Type I interferons (IFN-Is) have key roles in immune defense and treatments for various diseases, including chronic hepatitis B virus (HBV) infection. All IFN-Is signal through a shared IFN-I heterodimeric receptor complex comprising IFN-α receptor 1 (IFNAR1) and IFNAR2 subunits, but differences in antiviral and immunomodulatory responses among IFN-I subtypes remain largely unknown. Because the IFN-IFNAR interactions are species-specific, mice exhibit weak responses to human IFN-I. To more fully characterize the actions of human IFN-α and its subtypes in vivo, a gene targeting strategy was employed to generate gene knock-in mice with extracellular-humanized IFNAR1/2 (IFNAR-hEC) in the C57BL/6N strain. IFNAR-hEC mice actively responded to human IFN-I, and endogenous mouse IFN-I signalling remained active in heterozygous mice (IfnarhEC/+). Analyses of IFNAR-hEC mice and isolated cells showed that human IFN-α2 and α14 subtypes exerted differential effect on the activation of JAK-STAT signalling and immune responses. Compared with IFN-α2, IFN-α14 induced greater activation of STAT1/2 and IFN-stimulated genes, synergistically elicited IFN-α and -γ signalling, and induced higher numbers of antigen-specific CD8+ T cells. Moreover, IFNAR-hEC mice with HBV replication displayed long-term viral suppression upon treatment with the clinically-used PEGylated hIFN-α2. These results indicate that IFNAR-hEC mice may be useful for elucidating antiviral and immunomodulatory functions of human IFN-Is and for conducting preclinical studies. A better understanding of the distinct activities of IFN-α subtypes can provide insights concerning the development of improved IFN-based therapy.

Impact of glycosylation on viral vaccines

Glycosylation is the most prominent modification important for vaccines and its specific pattern depends on several factors that need to be considered when developing a new biopharmaceutical. Tailor-made glycosylation can be exploited to develop more effective and safer vaccines; for this reason, a deep understanding of both glycoengineering strategies and glycans structures and functions is required. In this review we discuss the recent advances concerning glycoprotein expression systems and the explanation of glycans immunomodulation mechanisms. Furthermore, we highlight how glycans tune the immunological properties among different vaccines platforms (whole virus, recombinant protein, nucleic acid), also comparing commercially available formulations and describing the state-of-the-art analytical technologies for glycosylation analysis. The whole review stresses the aspect of glycoprotein glycans as a potential tool to overcome nowadays medical needs in vaccine field.

Translational selenium nanoparticles boost GPx1 activation to reverse HAdV-14 virus-induced oxidative damage

Human adenovirus (HAdV) can cause severe respiratory infections in immunocompromised patients, but its clinical treatment is seriously limited by side effects of drugs such as poor efficacy, low bioavailability and severe nephrotoxicity. Trace element selenium (Se) has been found will affect the disease progression of pneumonia, but its antivirus efficacy could be improved by speciation optimization. Therefore, herein we performed anti-HAdV effects of different Se speciation and found that lentinan (LNT)-decorated selenium nanoparticles (SeNPs) exhibited low cytotoxicity and excellent anti-HAdV antiviral activity. Furthermore, SeNPs@LNT reduced the HAdV infection-induced mitochondrial damage and excessive production of reactive oxygen species (ROS). It was also involved in the repair of host cell DNA damage and inhibition of viral DNA replication. SeNPs@LNT inhibited HAdV-induced apoptosis mainly by modulating the p53/Bcl-2 apoptosis signaling pathway. In vivo, SeNPs@LNT replenished Se by targeting the infected site through the circulatory system and was involved in the synthesis of Glutathione peroxidase 1 (GPx1). More importantly, GPx1 played an antioxidant and immunomodulatory role in alleviating HAdV-induced inflammatory cytokine storm and alleviating adenovirus pneumonia in Se-deficient mice. Collectively, this study provides a Se speciation of SeNPs@LNT with anti-HAdV activity, and demonstrate that SeNPs@LNT is a promising pharmaceutical candidate for the treatment of HAdV.

Improved Preclinical Drug Metabolism and Pharmacokinetics of Pibothiadine (HEC121210), a Novel Hepatitis B Virus Capsid Assembly Modulator

Pibothiadine (PBD; HEC121120) is a novel hepatitis B virus capsid assembly modulator based on GLS4 (morphothiadine) and has inhibitory activities against resistant strains.To assess the overall preclinical drug metabolism and pharmacokinetics (DMPK) properties of PBD, in vivo pharmacokinetics studies in rats and dogs have been performed along with a series of in vitro metabolism assays.The oral bioavailability of PBD in rats and dogs might be related to its medium permeability in Caco-2 cells and largely be impacted by the pH-dependent solubility. PBD was highly distributed to the liver where the local exposure was 16.4 fold of the system exposure. PBD showed relatively low metabolic rate in recombinant human cytochrome P450 enzymes, whereas low to moderate in vitro clearance in liver microsomes and low (dog) to moderate (rat) in vivo clearance. Furthermore, β-oxidation and dehydrogenation were proposed as the primary metabolic pathways of PBD in rats.Compared to GLS4, the higher systemic exposure of PBD might be attributed to its improved oral absorption and metabolic stability. In addition, the enhanced liver/plasma exposure ratio could further increase the local exposure around the target. These improved DMPK properties might indicate better development of PBD in the clinical phase.

Varied immune responses of HBV-specific B cells in patients undergoing pegylated interferon-alpha treatment for chronic hepatitis B

BACKGROUND & AIMS

The changes of HBV-specific B-cells in chronic hepatitis B (CHB) patients underwent pegylated interferon-alfa (PEG-IFNα) treatment and achieved functional cure remain unclear. We aimed to evaluate the alterations in HBV-specific B-cells during treatment and therefore explored the mechanism of functional recovery of HBsAg-specific B-cells.

METHODS

We included 39 nucleos(t)ide analogues-treated CHB patients who received sequential combination therapy with PEG-IFNα and 8 treatment-naive CHB patients. HBV-specific B-cells were characterized ex vivo using fluorescent labeled HBsAg and HBcAg. The frequency, phenotype, and subsets of HBV-specific B-cells and follicular helper T cells (Tfh-cells) were detected using flow cytometry. The functionality of HBV-specific B-cells was quantified through ELISpot assays.

RESULTS

During treatment, the fraction of activated memory B-cells (MBCs) among HBsAg-specific B-cells and the expression of IgG, CXCR3, and CD38 increased. Antibody-secretion capacity of HBsAg-specific B-cell was restored after treatment only in patients with a functional cure and it showed a positive correlation with serum hepatitis B surface antibody levels. The phenotype and function of HBsAg-specific B-cells differed between patients with and without functional cure. Patients with functional cure exhibited IgG+ classical MBCs and plasmablasts in HBsAg-specific B-cells. HBcAg-specific B-cells displayed both attenuated antibody secretion with reduced IgG expression and an IgM+ atypical type of MBCs after treatment, irrespective of with and without functional cure. The number of CD40L+ Tfh-cells increased after PEG-IFNα treatment and positively correlated with HBsAg-specific B-cell activation.

CONCLUSIONS

After PEG-IFNα treatment, HBsAg- and HBcAg-specific B-cells exhibit various changes in antibody secretion. Their functional differences are reflected in the alterations in phenotypes and subtypes. The presence of CD40L+ Tfh-cells is associated with the active recovery of HBsAg-specific B-cells.

IMPACT AND IMPLICATIONS

HBV-related complications and hepatocellular carcinoma remain the leading causes of mortality from chronic liver disease worldwide, and a cure is rarely achieved with antiviral therapies. Elucidating the immunological mechanisms underlying the functional cure of CHB patients offers a promising therapeutic strategy for viral clearance, such as therapeutic vaccine. We analyzed the alterations in HBV-specific B-cells in patients treated with PEG-IFNα and identified novel pathways for immunotherapeutic boosting of B cell immunity.

Detection technology and clinical applications of serum viral products of hepatitis B virus infection

Viral hepatitis, caused by its etiology, hepatitis virus, is a public health problem globally. Among all infections caused by hepatitis-associated viruses, hepatitis B virus (HBV) infection remains the most serious medical concern. HBV infection particularly affects people in East Asia and Africa, the Mediterranean region, and Eastern Europe, with a prevalence rate of > 2%. Currently, approximately 1 billion people worldwide are infected with HBV, and nearly 30% of them experience chronic infection. Chronic HBV infection can lead to chronic hepatitis B (CHB), liver cirrhosis, and hepatocellular carcinoma (HCC), resulting in the related death of approximately 1 million people annually. Although preventative vaccines and antiviral therapies are currently available, there is no cure for this infection. Clinical testing is not only the gateway for diagnosis of HBV infection, but also crucial for judging the timing of medication, evaluating the effect of antiviral therapy, and predicting the risk of relapse after drug withdrawal in the whole follow-up management of hepatitis B infected persons. With advances in detection technology, it is now possible to measure various viral components in the blood to assess the clinical status of HBV infection. Serum viral products of HBV infection, such as HBV DNA, HBV RNA, hepatitis B surface antigen, hepatitis B e-antigen, and hepatitis B core-related antigen, are non-invasive indicators that are critical for the rapid diagnosis and management of related diseases. Improving the sensitivity of monitoring of these products is essential, and the development of corresponding detection technologies is pivotal in achieving this goal. This review aims to offer valuable insights into CHB infection and references for its effective treatment. We provide a comprehensive and systematic overview of classical and novel methods for detecting HBV serum viral products and discusses their clinical applications, along with the latest research progress in this field.

Novel role of MHC class II transactivator in hepatitis B virus replication and viral counteraction

BACKGROUND/AIMS

The major histocompatibility class II (MHC II) transactivator, known as CIITA, is induced by Interferon gamma (IFN-γ) and plays a well-established role in regulating the expression of class II MHC molecules in antigen-presenting cells.

METHODS

Primary human hepatocytes (PHH) were isolated via therapeutic hepatectomy from two donors. The hepatocellular carcinoma (HCC) cell lines HepG2 and Huh7 were used for the mechanistic study, and HBV infection was performed in HepG2-NTCP cells. HBV DNA replication intermediates and secreted antigen levels were measured using Southern blotting and ELISA, respectively.

RESULTS

We identified a non-canonical function of CIITA in the inhibition of hepatitis B virus (HBV) replication in both HCC cells and patient-derived PHH. Notably, in vivo experiments demonstrated that HBV DNA and secreted antigen levels were significantly decreased in mice injected with the CIITA construct. Mechanistically, CIITA inhibited HBV transcription and replication by suppressing the activity of HBV-specific enhancers/promoters. Indeed, CIITA exerts antiviral activity in hepatocytes through ERK1/2-mediated down-regulation of the expression of hepatocyte nuclear factor 1α (HNF1α) and HNF4α, which are essential factors for virus replication. In addition, silencing of CIITA significantly abolished the IFN-γ-mediated anti-HBV activity, suggesting that CIITA mediates the anti-HBV activity of IFN-γ to some extent. HBV X protein (HBx) counteracts the antiviral activity of CIITA via direct binding and impairing its function.

CONCLUSION

Our findings reveal a novel antiviral mechanism of CIITA that involves the modulation of the ERK pathway to restrict HBV transcription. Additionally, our results suggest the possibility of a new immune avoidance mechanism involving HBx.

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.

The nuclear matrix protein HNRNPU restricts hepatitis B virus transcription by promoting OAS3-based activation of host innate immunity

Heterogeneous nuclear protein U (HNRNPU) plays a pivotal role in innate immunity by facilitating chromatin opening to activate immune genes during host defense against viral infection. However, the mechanism by which HNRNPU is involved in Hepatitis B virus (HBV) transcription regulation through mediating antiviral immunity remains unknown. Our study revealed a significant decrease in HNRNPU levels during HBV transcription, which depends on HBx-DDB1-mediated degradation. Overexpression of HNRNPU suppressed HBV transcription, while its knockdown effectively promoted viral transcription, indicating HNRNPU as a novel host restriction factor for HBV transcription. Mechanistically, HNRNPU inhibits HBV transcription by activating innate immunity through primarily the positive regulation of the interferon-stimulating factor 2'-5'-oligoadenylate synthetase 3, which mediates an ribonuclease L-dependent mechanism to enhance innate immune responses. This study offers new insights into the host immune regulation of HBV transcription and proposes potential targets for therapeutic intervention against HBV infection.

Latest insights into the epidemiology, characteristics, and therapeutic strategies of chronic hepatitis B patients in indeterminate phase

As a hepatotropic virus, hepatitis B virus (HBV) can establish a persistent chronic infection in the liver, termed, chronic hepatitis B (CHB), which causes a series of liver-related complications, including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). HCC with HBV infection has a significantly increased morbidity and mortality, whereas it could be preventable. The current goal of antiviral therapy for HBV infection is to decrease CHB-related morbidity and mortality, and achieve sustained suppression of virus replication, which is known as a functional or immunological cure. The natural history of chronic HBV infection includes four immune phases: the immune-tolerant phase, immune-active phase, inactive phase, and reactivation phase. However, many CHB patients do not fit into any of these defined phases and are regarded as indeterminate. A large proportion of indeterminate patients are only treated with dynamic monitoring rather than recommended antiviral therapy, mainly due to the lack of definite guidelines. However, many of these patients may gradually have significant liver histopathological changes during disease progression. Recent studies have focused on the prevalence, progression, and carcinogenicity of indeterminate CHB, and more attention has been given to the prevention, detection, and treatment for these patients. Herein, we discuss the latest understanding of the epidemiology, clinical characteristics, and therapeutic strategies of indeterminate CHB, to provide avenues for the management of these patients.

Dopamine Inhibits the Expression of Hepatitis B Virus Surface and e Antigens by Activating the JAK/STAT Pathway and Upregulating Interferon-stimulated Gene 15 Expression

Background and Aims

Hepatitis B virus (HBV) infection is a major risk factor for cirrhosis and liver cancer, and its treatment continues to be difficult. We previously demonstrated that a dopamine analog inhibited the packaging of pregenomic RNA into capsids. The present study aimed to determine the effect of dopamine on the expressions of hepatitis B virus surface and e antigens (HBsAg and HBeAg, respectively) and to elucidate the underlying mechanism.

Methods

We used dopamine-treated HBV-infected HepG2.2.15 and NTCP-G2 cells to monitor HBsAg and HBeAg expression levels. We analyzed interferon-stimulated gene 15 (ISG15) expression in dopamine-treated cells. We knocked down ISG15 and then monitored HBsAg and HBeAg expression levels. We analyzed the expression of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway factors in dopamine-treated cells. We used dopamine hydrochloride-treated adeno-associated virus/HBV-infected mouse model to evaluate HBV DNA, HBsAg, and HBeAg expression. HBV virus was collected from HepAD38.7 cell culture medium.

Results

Dopamine inhibited HBsAg and HBeAg expression and upregulated ISG15 expression in HepG2.2.15 and HepG2-NTCP cell lines. ISG15 knockdown increased HBsAg and HBeAg expression in HepG2.2.15 cells. Dopamine-treated cells activated the JAK/STAT pathway, which upregulated ISG15 expression. In the adeno-associated virus-HBV murine infection model, dopamine downregulated HBsAg and HBeAg expression and activated the JAK-STAT/ISG15 axis.

Conclusions

Dopamine inhibits the expression of HBsAg and HBeAg by activating the JAK/STAT pathway and upregulating ISG15 expression.

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.

Deciphering the phospho-signature induced by hepatitis B virus in primary human hepatocytes

Phosphorylation is a major post-translation modification (PTM) of proteins which is finely tuned by the activity of several hundred kinases and phosphatases. It controls most if not all cellular pathways including anti-viral responses. Accordingly, viruses often induce important changes in the phosphorylation of host factors that can either promote or counteract viral replication. Among more than 500 kinases constituting the human kinome only few have been described as important for the hepatitis B virus (HBV) infectious cycle, and most of them intervene during early or late infectious steps by phosphorylating the viral Core (HBc) protein. In addition, little is known on the consequences of HBV infection on the activity of cellular kinases. The objective of this study was to investigate the global impact of HBV infection on the cellular phosphorylation landscape early after infection. For this, primary human hepatocytes (PHHs) were challenged or not with HBV, and a mass spectrometry (MS)-based quantitative phosphoproteomic analysis was conducted 2- and 7-days post-infection. The results indicated that while, as expected, HBV infection only minimally modified the cell proteome, significant changes were observed in the phosphorylation state of several host proteins at both time points. Gene enrichment and ontology analyses of up- and down-phosphorylated proteins revealed common and distinct signatures induced by infection. In particular, HBV infection resulted in up-phosphorylation of proteins involved in DNA damage signaling and repair, RNA metabolism, in particular splicing, and cytoplasmic cell-signaling. Down-phosphorylated proteins were mostly involved in cell signaling and communication. Validation studies carried out on selected up-phosphorylated proteins, revealed that HBV infection induced a DNA damage response characterized by the appearance of 53BP1 foci, the inactivation of which by siRNA increased cccDNA levels. In addition, among up-phosphorylated RNA binding proteins (RBPs), SRRM2, a major scaffold of nuclear speckles behaved as an antiviral factor. In accordance with these findings, kinase prediction analysis indicated that HBV infection upregulates the activity of major kinases involved in DNA repair. These results strongly suggest that HBV infection triggers an intrinsic anti-viral response involving DNA repair factors and RBPs that contribute to reduce HBV replication in cell culture models.

Anti-HBV Activities of Cembranoids from the South China Sea Soft Coral Sinularia pedunculata and Their Structure Activity Relationship

Hepatitis B Virus (HBV) infection is a global public health challenge that seriously endangers human health. Soft coral, as a major source of terpenoids, contains many structurally novel and highly bioactive compounds. Sixteen cembranoids (1-16), including a new one named sinupedunol B (16), were isolated from the South China Sea Soft coral Sinularia pedunculata. The structure of the sinupedunol B (16) was determined through a combination of spectroscopic analysis and X-ray single-crystal diffraction. In this study, cembranoids isolated from Sinularia pedunculata were found of anti-HBV activity for the first time. Among them, flexilarin D (6) showed significant anti-HBV activity with an IC50 value of 5.57 μM without cytotoxicity. We then analyzed the structure-activity relationship (SAR). Furthermore, it is demonstrated that flexilarin D (6) can accelerate the formation of capsid, inhibit HBeAg, HBV core particle DNA, HBV total RNA and pregenomic RNA in a dose dependent manner. We also confirmed the anti-HBV activity of 6 in HepG2-NTCP infection system. Finally, we demonstrated the anti-HBV mechanism of these compounds by inhibiting the ENI/Xp enhancer/promoter.

Uncommon Adverse Events of Immune Checkpoint Inhibitors in Small Cell Lung Cancer: A Systematic Review of Case Reports

BACKGROUND

This study aimed to systematically review case reports documenting rare adverse events in patients with small cell lung cancer (SCLC) following the administration of immune checkpoint inhibitors (ICIs).

METHODS

A systematic literature review was conducted to identify case reports detailing previously unreported adverse drug reactions to ICIs in patients with SCLC. The scope of the literature reviewed was restricted to case studies on SCLC published up to 31 December 2023.

RESULTS

We analyzed twenty-four studies on ICI use for patients with SCLC. There were six reports on atezolizumab, four on durvalumab, and three on adverse events from monotherapy with nivolumab. Reports involving combination treatments were the most frequent, with a total of six, predominantly involving using nivolumab in combination with ipilimumab. Additionally, there was one report each on using pembrolizumab, nofazinilimab, sintilimab, tislelizumab, and toripalimab. We collected detailed information on the clinical course, including patient and disease characteristics, symptoms, treatment for each adverse event, and recovery status. Among the patients included in the case reports, 21 out of 24 (87.5%) had extensive-stage SCLC when initiating ICI therapy, with only 1 patient diagnosed with limited-stage SCLC. Respiratory system adverse events were most common, with seven cases, followed by neurological, endocrinological, and gastroenterological events. Three case reports documented adverse events across multiple systems in a single patient. In most cases, patients showed symptom improvement; however, four studies reported cases where patients either expired without symptom improvement or experienced sequelae.

CONCLUSIONS

Efforts to develop reliable biomarkers for predicting irAEs continue, with ongoing research to enhance predictive precision. Immunotherapy presents diverse and unpredictable adverse events, underscoring the need for advanced diagnostic tools and a multidisciplinary approach to improve patient management.

Mesencephalic Astrocyte-derived Neurotrophic Factor Supports Hepatitis B Virus-induced Immunotolerance

BACKGROUND & AIMS

The immune tolerance induced by hepatitis B virus (HBV) is a major challenge for achieving effective viral clearance, and the mechanisms involved are not well-understood. One potential factor involved in modulating immune responses is mesencephalic astrocyte-derived neurotrophic factor (MANF), which has been reported to be increased in patients with chronic hepatitis B. In this study, our objective is to examine the role of MANF in regulating immune responses to HBV.

METHODS

We utilized a commonly used HBV-harboring mouse model, where mice were hydrodynamically injected with the pAAV/HBV1.2 plasmid. We assessed the HBV load by measuring the levels of various markers including hepatitis B surface antigen, hepatitis B envelope antigen, hepatitis B core antigen, HBV DNA, and HBV RNA.

RESULTS

Our study revealed that following HBV infection, both myeloid cells and hepatocytes exhibited increased expression of MANF. Moreover, we observed that mice with myeloid-specific MANF knockout (ManfMye-/-) displayed reduced HBV load and improved HBV-specific T cell responses. The decreased HBV-induced tolerance in ManfMye-/- mice was associated with reduced accumulation of myeloid-derived suppressor cells (MDSCs) in the liver. Restoring MDSC levels in ManfMye-/- mice through MDSC adoptive transfer reinstated HBV-induced tolerance. Mechanistically, we found that MANF promoted MDSC expansion by activating the IL-6/STAT3 pathway. Importantly, our study demonstrated the effectiveness of a combination therapy involving an hepatitis B surface antigen vaccine and nanoparticle-encapsulated MANF siRNA in effectively clearing HBV in HBV-carrier mice.

CONCLUSION

The current study reveals that MANF plays a previously unrecognized regulatory role in liver tolerance by expanding MDSCs in the liver through IL-6/STAT3 signaling, leading to MDSC-mediated CD8+ T cell exhaustion.

Arsenic trioxide impacts hepatitis B virus core nuclear localization and efficiently interferes with HBV infection

The key to a curative treatment of hepatitis B virus (HBV) infection is the eradication of the intranuclear episomal covalently closed circular DNA (cccDNA), the stable persistence reservoir of HBV. Currently, established therapies can only limit HBV replication but fail to tackle the cccDNA. Thus, novel therapeutic approaches toward curative treatment are urgently needed. Recent publications indicated a strong association between the HBV core protein SUMOylation and the association with promyelocytic leukemia nuclear bodies (PML-NBs) on relaxed circular DNA to cccDNA conversion. We propose that interference with the cellular SUMOylation system and PML-NB integrity using arsenic trioxide provides a useful tool in the treatment of HBV infection. Our study showed a significant reduction in HBV-infected cells, core protein levels, HBV mRNA, and total DNA. Additionally, a reduction, albeit to a limited extent, of HBV cccDNA could be observed. Furthermore, this interference was also applied for the treatment of an established HBV infection, characterized by a stably present nuclear pool of cccDNA. Arsenic trioxide (ATO) treatment not only changed the amount of expressed HBV core protein but also induced a distinct relocalization to an extranuclear phenotype during infection. Moreover, ATO treatment resulted in the redistribution of transfected HBV core protein away from PML-NBs, a phenotype similar to that previously observed with SUMOylation-deficient HBV core. Taken together, these findings revealed the inhibition of HBV replication by ATO treatment during several steps of the viral replication cycle, including viral entry into the nucleus as well as cccDNA formation and maintenance. We propose ATO as a novel prospective treatment option for further pre-clinical and clinical studies against HBV infection.

IMPORTANCE

The main challenge for the achievement of a functional cure for hepatitis B virus (HBV) is the covalently closed circular DNA (cccDNA), the highly stable persistence reservoir of HBV, which is maintained by further rounds of infection with newly generated progeny viruses or by intracellular recycling of mature nucleocapsids. Eradication of the cccDNA is considered to be the holy grail for HBV curative treatment; however, current therapeutic approaches fail to directly tackle this HBV persistence reservoir. The molecular effect of arsenic trioxide (ATO) on HBV infection, protein expression, and cccDNA formation and maintenance, however, has not been characterized and understood until now. In this study, we reveal ATO treatment as a novel and innovative therapeutic approach against HBV infections, repressing viral gene expression and replication as well as the stable cccDNA pool at low micromolar concentrations by affecting the cellular function of promyelocytic leukemia nuclear bodies.

The intersection of virus infection and liver disease: A comprehensive review of pathogenesis, diagnosis, and treatment

Liver disease represents a significant global burden, placing individuals at a heightened risk of developing cirrhosis and liver cancer. Viral infections act as a primary cause of liver diseases on a worldwide scale. Infections involving hepatitis viruses, notably hepatitis B, C, and E viruses, stand out as the most prevalent contributors to acute and chronic intrahepatic adverse outcome, although the hepatitis C virus (HCV) can be effectively cured with antiviral drugs, but no preventative vaccination developed. Hepatitis B virus (HBV) and HCV can lead to both acute and chronic liver diseases, including liver cirrhosis and hepatocellular carcinoma (HCC), which are principal causes of worldwide morbidity and mortality. Other viruses, such as Epstein-Barr virus (EBV) and cytomegalovirus (CMV), are capable of causing liver damage. Therefore, it is essential to recognize that virus infections and liver diseases are intricate and interconnected processes. A profound understanding of the underlying relationship between virus infections and liver diseases proves pivotal in the effective prevention, diagnosis, and treatment of these conditions. In this review, we delve into the mechanisms by which virus infections induce liver diseases, as well as explore the pathogenesis, diagnosis, and treatment of liver diseases. This article is categorized under: Infectious Diseases > Biomedical Engineering.

YF17D-based vaccines - standing on the shoulders of a giant

Live-attenuated yellow fever vaccine (YF17D) was developed in the 1930s as the first ever empirically derived human vaccine. Ninety years later, it is still a benchmark for vaccines made today. YF17D triggers a particularly broad and polyfunctional response engaging multiple arms of innate, humoral and cellular immunity. This unique immunogenicity translates into an extraordinary vaccine efficacy and outstanding longevity of protection, possibly by single-dose immunization. More recently, progress in molecular virology and synthetic biology allowed engineering of YF17D as a powerful vector and promising platform for the development of novel recombinant live vaccines, including two licensed vaccines against Japanese encephalitis and dengue, even in paediatric use. Likewise, numerous chimeric and transgenic preclinical candidates have been described. These include prophylactic vaccines against emerging viral infections (e.g. Lassa, Zika and SARS-CoV-2) and parasitic diseases (e.g. malaria), as well as therapeutic applications targeting persistent infections (e.g. HIV and chronic hepatitis), and cancer. Efforts to overcome historical safety concerns and manufacturing challenges are ongoing and pave the way for wider use of YF17D-based vaccines. In this review, we summarize recent insights regarding YF17D as vaccine platform, and how YF17D-based vaccines may complement as well as differentiate from other emerging modalities in response to unmet medical needs and for pandemic preparedness.

Incorporating Intracellular Processes in Virus Dynamics Models

In-host models have been essential for understanding the dynamics of virus infection inside an infected individual. When used together with biological data, they provide insight into viral life cycle, intracellular and cellular virus-host interactions, and the role, efficacy, and mode of action of therapeutics. In this review, we present the standard model of virus dynamics and highlight situations where added model complexity accounting for intracellular processes is needed. We present several examples from acute and chronic viral infections where such inclusion in explicit and implicit manner has led to improvement in parameter estimates, unification of conclusions, guidance for targeted therapeutics, and crossover among model systems. We also discuss trade-offs between model realism and predictive power and highlight the need of increased data collection at finer scale of resolution to better validate complex models.

CARs derived from broadly neutralizing, human monoclonal antibodies identified by single B cell sorting target hepatitis B virus-positive cells

To design new CARs targeting hepatitis B virus (HBV), we isolated human monoclonal antibodies recognizing the HBV envelope proteins from single B cells of a patient with a resolved infection. HBV-specific memory B cells were isolated by incubating peripheral blood mononuclear cells with biotinylated hepatitis B surface antigen (HBsAg), followed by single-cell flow cytometry-based sorting of live, CD19+ IgG+ HBsAg+ cells. Amplification and sequencing of immunoglobulin genes from single memory B cells identified variable heavy and light chain sequences. Corresponding immunoglobulin chains were cloned into IgG1 expression vectors and expressed in mammalian cells. Two antibodies named 4D06 and 4D08 were found to be highly specific for HBsAg, recognized a conformational and a linear epitope, respectively, and showed broad reactivity and neutralization capacity against all major HBV genotypes. 4D06 and 4D08 variable chain fragments were cloned into a 2nd generation CAR format with CD28 and CD3zeta intracellular signaling domains. The new CAR constructs displayed a high functional avidity when expressed on primary human T cells. CAR-grafted T cells proved to be polyfunctional regarding cytokine secretion and killed HBV-positive target cells. Interestingly, background activation of the 4D08-CAR recognizing a linear instead of a conformational epitope was consistently low. In a preclinical model of chronic HBV infection, murine T cells grafted with the 4D06 and the 4D08 CAR showed on target activity indicated by a transient increase in serum transaminases, and a lower number of HBV-positive hepatocytes in the mice treated. This study demonstrates an efficient and fast approach to identifying pathogen-specific monoclonal human antibodies from small donor cell numbers for the subsequent generation of new CARs.

CCL20 and CD8A as potential diagnostic biomarkers for HBV-induced liver fibrosis in chronic hepatitis B

Background

The main cause of the liver fibrosis (LF) remains hepatitis B virus (HBV) infection, especially in China. Histologically, liver fibrosis still occurs progressively in chronic hepatitis B (CHB) patients, even if HBV-DNA is negative or undetectable. The diagnosis of LF is beneficial to control the development of it, also it may promote the reversal of LF. Although liver biopsy is the gold standard of diagnosis in LF at present, it isa traumatic diagnosis. There are no diagnostic biomarkers as yet for the condition. It is badly in need of biomarkers clinically, which is simple to test, minimally invasive, highly specific, and sensitive. Early detection of HBV-LF development is crucial in the prevention, treatment, and prognosis prediction of HBV-LF. Cytokines are closely associated with both immune regulation and inflammation in the progression of hepatitis B virus associated-liver fibrosis (HBV-LF). In this bioinformatic study, we not only analyzed the relationship between HBV-LF and immune infiltration, but also identified key genes to uncover new therapeutic targets.

Objectives

To find potential biomarkers for liver fibrosis in the development of chronic hepatic B patients.

Materials and methods

We obtained two sets of data including CHB/healthy control and CHB/HBV-LF from the Integrated Gene Expression (GEO) database to select for differential expression analysis. Protein-protein interaction (PPI) network was also generated, while key genes and important gene modules involved in the occurrence and development of HBV-LF were identified. These key genes were analyzed by functional enrichment analysis, module analysis, and survival analysis. Furthermore, the relationship between these two diseases and immune infiltration was explored.

Results

Among the identified genes, 150 were individually associated with CHB and healthy control in the differential gene expression (DGE) analysis. While 14 with CHB and HBV-LF. It was also analyzed in the Robust rank aggregation (RRA) analysis, 34 differential genes were further identified by Cytohubba. Among 34 differential genes, two core genes were determined: CCL20 and CD8A. CCL20 was able to predict CHB positivity (area under the receiver operating characteristic curve [AUC-ROC] = 0.883, 95% confidence interval [CI] 0.786-0.963), while HBV-LF positivity ([AUC-ROC] = 0.687, 95% confidence interval [CI] 0.592-0.779). And CD8A was able to predict CHB positivity ([AUC-ROC] = 0.960, 95% confidence interval [CI] 0.915-0.992), while HBV-LF positivity ([AUC-ROC] = 0.773, 95% confidence interval [CI] 0.680-0.856). Relationship between CCL20 gene expression and LF grades was P < 0.05, as well as CD8A.

Conclusion

CCL20 and CD8A were found to be potential biomarkers and therapeutic targets for HBV-LF. It is instructive for research on the progression of LF in HBV patients, suppression of chronic inflammation, and development of molecularly targeted-therapy for HBV-LF.

Antiviral Therapy of Chronic Hepatitis B Virus between Present and Future

Background/Objectives: The objective of this study was to analyze the results of clinical trials regarding long-term antiviral therapies in chronic hepatitis with HBV to compare current therapeutic protocols and to analyze the results of preliminary studies with new antiviral therapies for HBV. Methods: Clinical studies and meta-analyses from PubMed, Google Scholar, and Research Gate from 2011 to 2024 were analyzed on patients undergoing chronic antiviral therapy for HBV, and a retrospective observational study performed in our clinic on a group of 76 patients undergoing chronic therapy with entecavir was presented. Also, a summary of the results of preliminary studies with various innovative antiviral molecules for HBV was performed. Results: The results of extensive clinical trials reveal that current therapies for chronic HBV are well tolerated and maintain good viral suppression if the patient is adherent to therapy. Innovative therapies aim to eliminate HBsAg and, thus, significantly shorten the duration of treatment, and the preliminary results of the studies are promising. Conclusions: Being an asymptomatic condition that requires life-long therapy, adherence to therapy is a real problem. Also, the risk of decompensation of liver cirrhosis and adenocarcinoma remains important in these patients. Future research is needed to perfect some antiviral therapy schemes that shorten the treatment period but also decrease the rate of progression towards decompensated cirrhosis and liver adenocarcinoma.

"PROTAC" modified dihydroquinolizinones (DHQs) that cause degradation of PAPD-5 and inhibition of hepatitis A virus and hepatitis B virus, in vitro

Dihydroquinolizinones (DHQs) that inhibit cellular polyadenylating polymerases 5 and 7 (PAPD5 & 7), such as RG7834, have been shown to inhibit both hepatitis A (HAV) and hepatitis B virus (HBV) in vitro and in vivo. In this report, we describe RG7834-based proteolysis-targeting chimeras (PROTACs), such as compound 12b, (6S)-9-((1-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)-21-oxo-3,6,9,12,15,18-hexaoxa-22-azapentacosan-25-yl)oxy)-6-isopropyl-10-methoxy-2-oxo-6,7-dihydro-2H-pyrido[2,1-a]isoquinoline-3-carboxylic acid. The PROTAC DHQs described here inhibited an HAV reporter virus in vitro with an IC50 of 277 nM. Although the PROTAC DHQs were also inhibitory to HBV, their activities were substantially less potent against HBV in vitro, being in the 10 to 20 µM range, based on the reduction of HBsAg and HBV mRNA levels. Importantly, unlike RG7834, the incubation of cells in vitro with PROTAC DHQ 12b resulted in the degradation of PAPD5, as expected for a PROTAC compound, but curiously not PAPD7. PAPD5 polypeptide degradation was prevented when a proteasome inhibitor, epoxomicin, was used, indicating that proteasome mediated proteolysis was associated with the observed activities of 12b. Taken together, these data show that 12b is the first example of a PROTAC that suppresses both HAV and HBV that is based on a small molecule warhead. The possibility that it has mechanisms that differ from its parent compound, RG7834, and has clinical value, is discussed.

Hepatitis B surface antigen expression impairs endoplasmic reticulum stress-related autophagic flux by decreasing LAMP2

Background & Aims

Hepatitis B surface antigen (HBsAg) drives hepatocarcinogenesis. Factors and mechanisms involved in this progression remain poorly defined, hindering the development of effective therapeutic strategies. Therefore, the mechanisms involved in the HBsAg-induced transformation of normal liver into hepatocellular carcinoma (HCC) were investigated.

Methods

Hemizygous Tg(Alb1HBV)44Bri/J mice were examined for HBsAg-induced carcinogenic events. Gene set-enrichment analysis identified significant signatures in HBsAg-transgenic mice that correlated with endoplasmic reticulum (ER) stress, unfolded protein response, autophagy and proliferation. These events were investigated by western blotting, immunohistochemical and immunocytochemical staining in 2-, 8- and 12-month-old HBsAg-transgenic mice. The results were verified in HBsAg-overexpressing Hepa1-6 cells and validated in human HBV-related HCC samples.

Results

Increased BiP expression in HBsAg-transgenic mice indicated induction of the unfolded protein response. In addition, early-phase autophagy was enhanced (increased BECN1 and LC3B) and late-phase autophagy blocked (increased p62) in HBsAg-transgenic mice. Finally, HBsAg altered lysosomal acidification via ATF4- and ATF6-mediated downregulation of lysosome-associated membrane protein 2 (LAMP2) expression. In patients, HBV-related HCC and adjacent tissues showed increased BiP, p62 and downregulated LAMP2 compared to uninfected controls. In vitro, the use of ER stress inhibitors reversed the HBsAg-related suppression of LAMP2. Furthermore, HBsAg promoted hepatocellular proliferation as indicated by Ki67, cleaved caspase-3 and AFP staining in paraffin-embedded liver sections from HBsAg-transgenic mice. These results were further verified by colony formation assays in HBsAg-expressing Hepa1-6 cells. Interestingly, inhibition of ER stress in HBsAg-overexpressing Hepa1-6 cells suppressed HBsAg-mediated cell proliferation.

Conclusions

These data showed that HBsAg directly induces ER stress, impairs autophagy and promotes proliferation, thereby driving hepatocarcinogenesis. In addition, this study expanded the understanding of HBsAg-mediated intracellular events in carcinogenesis.

Impact and implications

Factors and mechanisms involved in hepatocarcinogenesis driven by hepatitis B surface antigen (HBsAg) are poorly defined, hindering the development of effective therapeutic strategies. This study showed that HBsAg-induced endoplasmic reticulum stress suppressed LAMP2, thereby mediating autophagic injury. The present data suggest that restoring LAMP2 function in chronic HBV infection may have both antiviral and anti-cancer effects. This study has provided insights into the role of HBsAg-mediated intracellular events in carcinogenesis and thereby has relevance for future drug development.

A Dual-domain Engineered Antibody for Efficient HBV Suppression and Immune Responses Restoration

Chronic hepatitis B (CHB) remains a major public health concern because of the inefficiency of currently approved therapies in clearing the hepatitis B surface antigen (HBsAg). Antibody-based regimens have demonstrated potency regarding virus neutralization and HBsAg clearance. However, high dosages or frequent dosing are required for virologic control. In this study, a dual-domain-engineered anti-hepatitis B virus (HBV) therapeutic antibody 73-DY is developed that exhibits significantly improved efficacy regarding both serum and intrahepatic viral clearance. In HBV-tolerant mice, administration of a single dose of 73-DY at 2 mg kg-1 is sufficient to reduce serum HBsAg by over 3 log10 IU mL-1 and suppress HBsAg to < 100 IU mL-1 for two weeks, demonstrating a dose-lowering advantage of at least tenfold. Furthermore, 10 mg kg-1 of 73-DY sustainably suppressed serum viral levels to undetectable levels for ≈ 2 weeks. Molecular analyses indicate that the improved efficacy exhibited by 73-DY is attributable to the synergy between fragment antigen binding (Fab) and fragment crystallizable (Fc) engineering, which conferred sustained viral suppression and robust viral eradication, respectively. Long-term immunotherapy with reverse chimeric 73-DY facilitated the restoration of anti-HBV immune responses. This study provides a foundation for the development of next-generation antibody-based CHB therapies.

Leveraging stem cells to combat hepatitis: a comprehensive review of recent studies

Hepatitis is a significant global public health concern, with viral infections being the most common cause of liver inflammation. Antiviral medications are the primary treatments used to suppress the virus and prevent liver damage. However, the high cost of these drugs and the lack of awareness and stigma surrounding the disease create challenges in managing hepatitis. Stem cell therapy has arisen as a promising therapeutic strategy for hepatitis by virtue of its regenerative and immunomodulatory characteristics. Stem cells have the exceptional capacity to develop into numerous cell types and facilitate tissue regeneration, rendering them a highly promising therapeutic avenue for hepatitis. In animal models, stem cell therapy has demonstrated worthy results by reducing liver inflammation and improving liver function. Furthermore, clinical trials have been undertaken to assess the safety and effectiveness of stem cell therapy in individuals with hepatitis. This review aims to explore the involvement of stem cells in treating hepatitis and highlight the findings from studies conducted on both animals and humans. The objective of this review is to primarily concentrate on the ongoing and future clinical trials that assess the application of stem cell therapy in the context of hepatitis, including the transplantation of autologous bone marrow-derived stem cells, human induced pluripotent stem cells, and other mesenchymal stem cells. In addition, this review will explore the potential merits and constraints linked to stem cell therapy for hepatitis, as well as its prospective implications in the management of this disease.

Advances in discovery of novel investigational agents for functional cure of chronic hepatitis B: A comprehensive review of phases II and III therapeutic agents

Chronic hepatitis B virus (HBV) infection affects over 295 million people globally and an estimated 1.6 million people in the United States. It is associated with significant morbidity and mortality due to cirrhosis, liver failure, and liver cancer. Antiviral therapy with oral nucleos(t)ide analogues is associated with high rates of virologic suppression, which in turn has been associated with a decreased risk of liver complications. However, current antiviral regimens are limited by concerns with adverse effects, adherence, resistance, long-term treatment, and ongoing risk for liver events. Novel investigational agents are currently in development and are targeted at achieving functional cure with sustained hepatitis B surface antigen (HBsAg) loss and suppression of HBV DNA. Herein we review key evidence from phases II and III trials defining the efficacy and safety profiles for key investigational agents for functional cure of chronic hepatitis B, including core/capsid inhibitors, entry inhibitors, RNA interference (siRNA/ASO), HBsAg inhibitors, Toll-like receptor agonists, checkpoint inhibitors, and therapeutic vaccines.

Innovative pharmacotherapy for hepatic metabolic and chronic inflammatory diseases in China

Liver disease constitutes a significant global health concern, particularly in China where it has distinctive characteristics. China grapples with a staggering 300 million cases, predominantly due to hepatitis B and metabolic non-alcoholic fatty liver disease. Additionally, hepatocellular carcinoma has become a prevalent which is a lethal type of cancer. Despite the scarcity of innovative treatment options, Chinese hepatologists and researchers have achieved notable breakthroughs in the prevention, diagnosis, management and treatment of liver diseases. Traditional Chinese medicines have found widespread application in the treatment of various liver ailments owing to their commendable pharmacological efficacy and minimal side effects. Furthermore, there is a growing body of research in extracellular vesicles, cell therapy and gene therapy, offering new hope in the fight against liver diseases. This paper provides a comprehensive overview of the epidemiological characteristics of liver diseases and the diverse array of treatments that Chinese scholars and scientists have pursued in critical field.

HBsAg level defines different clinical phenotypes of HBeAg(-) chronic HBV infection related to HBV polymerase-specific CD8+ cell response quality

Background

HBe-antigen(Ag)-negative chronic hepatitis B virus (HBV) infection is characterized by little liver fibrosis progression and vigorous HBV-multispecific CD8+ T-cell response.

Aims

To assess whether HBsAg level could discriminate different HBeAg-negative chronic HBV infection subtypes with dissimilar quality of HBV-specific CD8+ T-cell response.

Methods

We recruited 63 HBeAg-negative chronic HBV infection patients in which indirect markers of liver inflammation/fibrosis, portal pressure, viral load (VL), and HBV-specific CD8+ cell effector function were correlated with HBsAg level.

Results

A positive linear trend between HBsAg level and APRI, liver stiffness (LS), liver transaminases, and HBV VL, and a negative correlation with platelet count were observed. Frequency of cases with HBV-specific CD8+ T-cell proliferation against at least two HBV epitopes was higher in HBsAg < 1,000 IU/ml group. CD8+ T-cell expansion after HBVpolymerase456-63-specific stimulation was impaired in HBsAg > 1,000 IU/ml group, while the response against HBVcore18-27 was preserved and response against envelope183-91 was nearly abolished, regardless of HBsAg level. Cases with preserved HBVpolymerase456-63 CD8+ cell response had lower LS/duration of infection and APRI/duration of infection rates. HBV-polymerase456-63-specific CD8+ T-cell proliferation intensity was negatively correlated with LS/years of infection ratio.

Conclusion

HBsAg > 1,000 IU/ml HBeAg-negative chronic HBV infection group shows indirect data of higher degree of inflammation, liver stiffness, and fibrosis progression speed, which are related to an impaired HBV-polymerase-specific CD8+ T-cell response.

Cytosine base editing inhibits hepatitis B virus replication and reduces HBsAg expression in vitro and in vivo

Chronic hepatitis B virus (HBV) infection remains a global health problem due to the lack of treatments that prevent viral rebound from HBV covalently closed circular (ccc)DNA. In addition, HBV DNA integrates in the human genome, serving as a source of hepatitis B surface antigen (HBsAg) expression, which impairs anti-HBV immune responses. Cytosine base editors (CBEs) enable precise conversion of a cytosine into a thymine within DNA. In this study, CBEs were used to introduce stop codons in HBV genes, HBs and Precore. Transfection with mRNA encoding a CBE and a combination of two guide RNAs led to robust cccDNA editing and sustained reduction of the viral markers in HBV-infected HepG2-NTCP cells and primary human hepatocytes. Furthermore, base editing efficiently reduced HBsAg expression from HBV sequences integrated within the genome of the PLC/PRF/5 and HepG2.2.15 cell lines. Finally, in the HBV minicircle mouse model, using lipid nanoparticulate delivery, we demonstrated antiviral efficacy of the base editing approach with a >3log10 reduction in serum HBV DNA and >2log10 reduction in HBsAg, and 4/5 mice showing HBsAg loss. Combined, these data indicate that base editing can introduce mutations in both cccDNA and integrated HBV DNA, abrogating HBV replication and silencing viral protein expression.

Quantification of circulating HBV RNA expressed from intrahepatic cccDNA in untreated and NUC treated patients with chronic hepatitis B

OBJECTIVE

A convenient, reproducible biomarker of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) transcriptional activity is lacking. We measured circulating HBV RNA (cirB-RNA) in untreated and nucleos(t)ide analogues (NUC) treated chronic hepatitis B (CHB) patients to define its correlation with intrahepatic viral markers and HBV core-related antigen (HBcrAg).

DESIGN

Paired liver biopsy and serum samples were collected from 122 untreated and 30 NUC-treated CHB patients. We measured cirB-RNA, HBV DNA, hepatitis B surface antigen (HBsAg), HBcrAg and alanine aminotransferase levels. cirB-RNA was quantified using an investigational HBV RNA assay for use on the cobas 6800 system. The test detects a region spanning the HBV canonical polyadenylation site. cccDNA and 3.5 kb RNA in liver tissue were assessed by quantitative PCR and droplet digital PCR.

RESULTS

cirB-RNA was detectable in 100% of HBeAg(+) chronic hepatitis (CH), 57% and 14% of HBeAg(-) CH and chronic infection untreated patients and 47% of NUC-treated patients. cirB-RNA undetectability was associated with lower intrahepatic cccDNA transcriptional activity, as well as serum HBcrAg, but no significant differences in HBsAg, in both untreated and treated patients. In untreated HBeAg(-) patients, cirB-RNA correlated with intrahepatic 3.5 kb RNA and cccDNA transcriptional activity, serum HBV DNA and HBcrAg, but not with HBsAg or total cccDNA levels. Combined undetectability of both cirB-RNA and HBcrAg detection in untreated HBeAg(-) patients identified a subgroup with the lowest levels of intrahepatic transcriptionally active cccDNA.

CONCLUSION

Our results support the usefulness of quantification of circulating HBV RNA expressed from cccDNA as an indicator of intrahepatic active viral reservoir in both untreated and NUC-treated CHB patients.

TRIAL REGISTRATION NUMBER

NCT02602847.

Antiviral effect of peptoids on hepatitis B virus infection in cell culture

Although antimicrobial peptides have been shown to inactivate viruses through disruption of their viral envelopes, clinical use of such peptides has been hampered by a number of factors, especially their enzymatically unstable structures. To overcome the shortcomings of antimicrobial peptides, peptoids (sequence-specific N-substituted glycine oligomers) mimicking antimicrobial peptides have been developed. We aimed to demonstrate the antiviral effects of antimicrobial peptoids against hepatitis B virus (HBV) in cell culture. The anti-HBV activity of antimicrobial peptoids was screened and evaluated in an infection system involving the HBV reporter virus and HepG2.2.15-derived HBV. By screening with the HBV reporter virus infection system, three (TM1, TM4, and TM19) of 12 peptoids were identified as reducing the infectivity of HBV, though they did not alter the production levels of HBs antigen in cell culture. These peptoids were not cytotoxic at the evaluated concentrations. Among these peptoids, TM19 was confirmed to reduce HBV infection most potently in a HepG2.2.15-derived HBV infection system that closely demonstrates authentic HBV infection. In cell culture, the most effective administration of TM19 was virus treatment at the infection step, but the reduction in HBV infectivity by pre-treatment or post-treatment of cells with TM19 was minimal. The disrupting effect of TM19 targeting infectious viral particles was clarified in iodixanol density gradient analysis. In conclusion, the peptoid TM19 was identified as a potent inhibitor of HBV. This peptoid prevents HBV infection by disrupting viral particles and is a candidate for a new class of anti-HBV reagents.

The Microbiome Matters: Its Impact on Cancer Development and Therapeutic Responses

In the evolving landscape of cancer research, the human microbiome emerges as a pivotal determinant reshaping our understanding of tumorigenesis and therapeutic responses. Advanced sequencing technologies have uncovered a vibrant microbial community not confined to the gut but thriving within tumor tissues. Comprising bacteria, viruses, and fungi, this diverse microbiota displays distinct signatures across various cancers, with most research primarily focusing on bacteria. The correlations between specific microbial taxa within different cancer types underscore their pivotal roles in driving tumorigenesis and influencing therapeutic responses, particularly in chemotherapy and immunotherapy. This review amalgamates recent discoveries, emphasizing the translocation of the oral microbiome to the gut as a potential marker for microbiome dysbiosis across diverse cancer types and delves into potential mechanisms contributing to cancer promotion. Furthermore, it highlights the adverse effects of the microbiome on cancer development while exploring its potential in fortifying strategies for cancer prevention and treatment.

An Overview of the Unfolded Protein Response (UPR) and Autophagy Pathways in Human Viral Oncogenesis

Autophagy and Unfolded Protein Response (UPR) can be regarded as the safe keepers of cells exposed to intense stress. Autophagy maintains cellular homeostasis, ensuring the removal of foreign particles and misfolded macromolecules from the cytoplasm and facilitating the return of the building blocks into the system. On the other hand, UPR serves as a shock response to prolonged stress, especially Endoplasmic Reticulum Stress (ERS), which also includes the accumulation of misfolded proteins in the ER. Since one of the many effects of viral infection on the host cell machinery is the hijacking of the host translational system, which leaves in its wake a plethora of misfolded proteins in the ER, it is perhaps not surprising that UPR and autophagy are common occurrences in infected cells, tissues, and patient samples. In this book chapter, we try to emphasize how UPR, and autophagy are significant in infections caused by six major oncolytic viruses-Epstein-Barr (EBV), Human Papilloma Virus (HPV), Human Immunodeficiency Virus (HIV), Human Herpesvirus-8 (HHV-8), Human T-cell Lymphotropic Virus (HTLV-1), and Hepatitis B Virus (HBV). Here, we document how whole-virus infection or overexpression of individual viral proteins in vitro and in vivo models can regulate the different branches of UPR and the various stages of macro autophagy. As is true with other viral infections, the relationship is complicated because the same virus (or the viral protein) exerts different effects on UPR and Autophagy. The nature of this response is determined by the cell types, or in some cases, the presence of diverse extracellular stimuli. The vice versa is equally valid, i.e., UPR and autophagy exhibit both anti-tumor and pro-tumor properties based on the cell type and other factors like concentrations of different metabolites. Thus, we have tried to coherently summarize the existing knowledge, the crux of which can hopefully be harnessed to design vaccines and therapies targeted at viral carcinogenesis.

Drug Nanocrystals: A Delivery Channel for Antiviral Therapies

Viral infections represent a significant threat to global health due to their highly communicable and potentially lethal nature. Conventional antiviral interventions encounter challenges such as drug resistance, tolerability issues, specificity concerns, high costs, side effects, and the constant mutation of viral proteins. Consequently, the exploration of alternative approaches is imperative. Therefore, nanotechnology-embedded drugs excelled as a novel approach purporting severe life-threatening viral disease. Integrating nanomaterials and nanoparticles enables ensuring precise drug targeting, improved drug delivery, and fostered pharmacokinetic properties. Notably, nanocrystals (NCs) stand out as one of the most promising nanoformulations, offering remarkable characteristics in terms of physicochemical properties (higher drug loading, improved solubility, and drug retention), pharmacokinetics (enhanced bioavailability, dose reduction), and optical properties (light absorptivity, photoluminescence). These attributes make NCs effective in diagnosing and ameliorating viral infections. This review comprises the prevalence, pathophysiology, and resistance of viral infections along with emphasizing on failure of current antivirals in the management of the diseases. Moreover, the review also highlights the role of NCs in various viral infections in mitigating, diagnosing, and other NC-based strategies combating viral infections. In vitro, in vivo, and clinical studies evident for the effectiveness of NCs against viral pathogens are also discussed.

Classifying hepatitis B therapies with insights from covalently closed circular DNA dynamics

The achievement of a functional cure for chronic hepatitis B (CHB) remains limited to a minority of patients treated with currently approved drugs. The primary objective in developing new anti-HBV drugs is to enhance the functional cure rates for CHB. A critical prerequisite for the functional cure of CHB is a substantial reduction, or even eradication of covalently closed circular DNA (cccDNA). Within this context, the changes in cccDNA levels during treatment become as a pivotal concern. We have previously analyzed the factors influencing cccDNA dynamics and introduced a preliminary classification of hepatitis B treatment strategies based on these dynamics. In this review, we employ a systems thinking perspective to elucidate the fundamental aspects of the HBV replication cycle and to rationalize the classification of treatment strategies according to their impact on the dynamic equilibrium of cccDNA. Building upon this foundation, we categorize current anti-HBV strategies into two distinct groups and advocate for their combined use to significantly reduce cccDNA levels within a well-defined timeframe.

IL-15 boosts activated HBV core-specific CD8+ progenitor cells via metabolic rebalancing in persistent HBV infection

A rebalance between energy supply and demand in HBV-specific-CD8+ activated progenitor (AP) cells could restore the functionality of proliferative progeny (PP) in e-antigen(Ag)-negative chronic hepatitis B (CHBe(-)). We observed that quiescent progenitor (QP [TCF1+/FSClow]) HBVcore-specific-CD8+ cells displayed a memory-like phenotype. Following Ag-encounter, the generated AP [TCF1+/FSChigh] subset maintained the PD1+/CD127+ phenotype and gave rise to proliferative progeny (PP [ TCF1-/FSChigh]). In AP cells, IL-15 compared to IL2 decreased the initial mTORC1 boost, but maintained its activation longer linked to a catabolic profile that correlated with enhanced PP effector abilities. In nucleos(t)ide analogue (NUC)-treated CHBe(-), AP subset showed an anabolic phenotype associated with a dysfunctional PP pool. In CHBe(-) cases with low probability of HBVcore-specific-CD8+ cell on-NUC-treatment restoration, according to a clinical predictive model, IL-15/anti-PD-L1 treatment re-established their reactivity. Therefore, IL-15 could improve AP pool energy balance by decreasing intensity but extending T cell activation and by inducing a more catabolic metabolism.

The novel mechanism facilitating chronic hepatitis B infection: immunometabolism and epigenetic modification reprogramming

Hepatitis B Virus (HBV) infections pose a global public health challenge. Despite extensive research on this disease, the intricate mechanisms underlying persistent HBV infection require further in-depth elucidation. Recent studies have revealed the pivotal roles of immunometabolism and epigenetic reprogramming in chronic HBV infection. Immunometabolism have identified as the process, which link cell metabolic status with innate immunity functions in response to HBV infection, ultimately contributing to the immune system's inability to resolve Chronic Hepatitis B (CHB). Within hepatocytes, HBV replication leads to a stable viral covalently closed circular DNA (cccDNA) minichromosome located in the nucleus, and epigenetic modifications in cccDNA enable persistence of infection. Additionally, the accumulation or depletion of metabolites not only directly affects the function and homeostasis of immune cells but also serves as a substrate for regulating epigenetic modifications, subsequently influencing the expression of antiviral immune genes and facilitating the occurrence of sustained HBV infection. The interaction between immunometabolism and epigenetic modifications has led to a new research field, known as metabolic epigenomics, which may form a mutually reinforcing relationship with CHB. Herein, we review the recent studies on immunometabolism and epigenetic reprogramming in CHB infection and discuss the potential mechanisms of persistent HBV infection. A deeper understanding of these mechanisms will offer novel insights and targets for intervention strategies against chronic HBV infection, thereby providing new hope for the treatment of related diseases.

Detection of serum large and middle hepatitis B virus surface proteins: A novel potential diagnostic and prognostic biomarker for chronic hepatitis B

BACKGROUND

The significance of large (LHB) and middle (MHB) HBV surface proteins in chronic hepatitis B (CHB) remains uncertain. This study investigates the role of LHB and MHB in different infection phases and liver diseases.

METHODS

Serum samples from 217 patients with HBV chronic infection, CHB, liver cirrhosis (LC), and hepatocellular carcinoma (HCC) were subjected to quantification of LHB and MHB using ELISA.

RESULTS

Positive correlations were observed among LHB, MHB, and LHB/HBsAg, with HBV serum markers including HBsAg, HBeAg, and HBV DNA. (P < 0.0001). In HBeAg-positive chronic infection, LHB and MHB were higher than in HBeAg-positive CHB (P < 0.01). In HBeAg-negative chronic infection, LHB and MHB were lower than in HBeAg-negative CHB (P < 0.01). ROC analysis identified LHB and MHB as potential discriminators of CHB and chronic infection. LC and HCC exhibited lower LHB, MHB, and MHB/HBsAg than CHB (P < 0.05). Multivariate analysis found that age and the MHB/HBsAg serve as independent factors for the progression of CHB to end stage of liver disease.

CONCLUSIONS

LHB and MHB emerge as novel biomarkers distinguishing chronic infection and CHB. MHB/HBsAg shows promise as a predictor for CHB progression.

Novel function of MOTS-c in mitochondrial remodelling contributes to its antiviral role during HBV infection

OBJECTIVE

Hepatitis B virus (HBV) infection causes substantial harm to mitochondrial activity, which hinders the development of effective treatments for chronic hepatitis B (CHB). The discovery of the mitochondrial-derived short peptide MOTS-c, which possesses multiple bioactivities, offers a promising new approach in treating HBV infection. This study aims to explore the diagnostic and therapeutic potential of MOTS-c in HBV-related diseases and its molecular mechanism.

DESIGN

In total, 85 healthy subjects and 404 patients with HBV infection, including 20 clinical treatment cohorts, were recruited for this study. MOTS-c levels were measured by ELISA and its diagnostic value was evaluated by receiving operating characteristic curve analysis. The therapeutic effect of MOTS-c was observed in multiple HBV-infected mice and cells through various techniques, including transcriptomic sequencing, flow cytometry, immunofluorescence and electron microscopy. Additionally, MOTS-c's potential interaction with myosin-9 (MYH9) and actin was predicted using immunoprecipitation, proteomics and target prediction software.

RESULTS

MOTS-c negatively correlates with HBV DNA expression (R=-0.71), and its AUC (the area under the curve) for distinguishing CHB from healthy controls is 0.9530, and IA (immune reactive) from IC (inactive HBV carrier) is 0.8689. Inhibition of HBV replication (with a 50-70% inhibition rate) was observed alongside improved liver function without notable toxicity in vitro or in vivo. MOTS-c was found to promote mitochondrial biogenesis and enhance the MAVS (mitochondrial antiviral signalling protein) signalling pathway. The impact is dependent on MOTS-c's ability to regulate MYH9-actin-mediated mitochondrial homeostasis.

CONCLUSION

MOTS-c has the potential to serve as a biomarker for the progression of HBV infection while also enhancing antiviral efficacy. These findings present a promising innovative approach for effectively treating patients with CHB. Furthermore, our research uncovers a novel role for MOTS-c in regulating MYH9-actin-mediated mitochondrial dynamics and contributing to mitochondrial biogenesis.

Chromatin binding protein HMGN1 promotes HBV cccDNA transcription and replication by regulating the phosphorylation of histone 3

BACKGROUND AND AIMS

Direct elimination of cccDNA remains a formidable obstacle due to the persistent and stable presence of cccDNA in hepatocyte nuclei. The silencing of cccDNA transcription enduringly is one of alternative strategies in the treatment of hepatitis B. Protein binding to cccDNA plays an important role in its transcriptional regulation; thus, the identification of key factors involved in this process is of great importance.

APPROACHES AND RESULTS

In the present study, high mobility group nucleosome binding domain 1 (HMGN1) was screened out based on our biotin-avidin enrichment system. First, chromatin immunoprecipitation and fluorescent in situ hybridization assays confirmed the binding of HMGN1 with cccDNA in the nucleus. Second, functional experiments in HBV-infected cells showed that the promoting effect of HMGN1 on HBV transcription and replication depended on the functional region of the nucleosomal binding domain, while transfection of the HMGN1 mutant showed no influence on HBV compared with the vector. Third, further mechanistic exploration revealed that the silencing of HMGN1 increased the level of phosphorylase CLK2 and promoted H3 phosphorylation causing the reduced accessibility of cccDNA. Moreover, silenced HMGN1 was mimicked in HBV (r) cccDNA mouse model of HBV infection in vivo. The results showed that silencing HMGN1 inhibited HBV replication in vivo.

CONCLUSIONS

In summary, our study identified that a host protein can bind to cccDNA and promote its transcription, providing a candidate strategy for anti-HBV targeting to interfere with the transcriptional activity of cccDNA microchromosomes.

Serum vitamin D deficiency is associated with increased risk of γδ T cell exhaustion in HBV-infected patients

Previous studies have demonstrated that T cell exhaustion is associated with poor clearance of Hepatitis B virus (HBV). However, whether the expression of exhaustion markers on innate-like circulating γδ T cells derived from patients with HBV infection correlates with the serum level of vitamin D is not completely understood. In this study, we found that the frequency of circulating Vδ2+ T cell and serum levels of vitamin 25(OH)D3 were significantly decreased in patients with HBV. And serum 25(OH)D3 levels in HBV-infected patients were negatively correlated with HBV DNA load and PD-1 expression on γδ T cells. Interestingly, 1α,25(OH)2 D3 alleviated the exhaustion phenotype of Vδ2 T cells in HBV-infected patients and promoted IFN-β expression in human cytotoxic Vδ2 T cells in vitro. Collectively, these findings demonstrate that vitamin D plays a pivotal role in reversing γδ T-cell exhaustion and is highly promising target for ameliorating HBV infection.

A glycoengineered therapeutic anti-HBV antibody that allows increased HBsAg immunoclearance improves HBV suppression in vivo

Introduction: The effective and persistent suppression of hepatitis B surface antigen (HBsAg) in patients with chronic HBV infection (CHB) is considered to be a promising approach to achieve a functional cure of hepatitis B. In our previous study, we found that the antibody E6F6 can clear HBsAg through FcγR-mediated phagocytosis, and its humanized form (huE6F6 antibody) is expected to be a new tool for the treatment of CHB. Previous studies have shown that the glycosylation of Fc segments affects the binding of antibodies to FcγR and thus affects the biological activity of antibodies in vivo. Methods: To further improve the therapeutic potential of huE6F6, in this study, we defucosylated huE6F6 (huE6F6-fuc-), preliminarily explored the developability of this molecule, and studied the therapeutic potential of this molecule and its underlying mechanism in vitro and in vivo models. Results: huE6F6-fuc- has desirable physicochemical properties. Compared with huE6F6-wt, huE6F6-fuc- administration resulted in a stronger viral clearance in vivo. Meanwhile, huE6F6-fuc- keep a similar neutralization activity and binding activity to huE6F6-wt in vitro. Immunological analyses suggested that huE6F6-fuc- exhibited enhanced binding to hCD32b and hCD16b, which mainly contributed to its enhanced therapeutic activity in vivo. Conclusions: In summary, the huE6F6-fuc- molecule that was developed in this study, which has desirable developability, can clear HBsAg more efficiently in vivo, providing a promising treatment for CHB patients. Our study provides new guidance for antibody engineering in other disease fields.

Hepatitis B Virus and microRNAs: A Bioinformatics Approach

In recent decades, microRNAs (miRNAs) have emerged as key regulators of gene expression, and the identification of viral miRNAs (v-miRNAs) within some viruses, including hepatitis B virus (HBV), has attracted significant attention. HBV infections often progress to chronic states (CHB) and may induce fibrosis/cirrhosis and hepatocellular carcinoma (HCC). The presence of HBV can dysregulate host miRNA expression, influencing several biological pathways, such as apoptosis, innate and immune response, viral replication, and pathogenesis. Consequently, miRNAs are considered a promising biomarker for diagnostic, prognostic, and treatment response. The dynamics of miRNAs during HBV infection are multifaceted, influenced by host variability and miRNA interactions. Given the ability of miRNAs to target multiple messenger RNA (mRNA), understanding the viral-host (human) interplay is complex but essential to develop novel clinical applications. Therefore, bioinformatics can help to analyze, identify, and interpret a vast amount of miRNA data. This review explores the bioinformatics tools available for viral and host miRNA research. Moreover, we introduce a brief overview focusing on the role of miRNAs during HBV infection. In this way, this review aims to help the selection of the most appropriate bioinformatics tools based on requirements and research goals.

Serum HBV RNA levels among untreated adults with chronic hepatitis B in distinct immune phases and liver histopathology statuses

HBV RNA is a novel serum biomarker that reflects intrahepatic HBV covalently closed circular DNA (cccDNA) transcription activity. Serum HBV RNA levels among treatment-naïve adults during the natural history of chronic hepatitis B (CHB) and distinct liver histopathology statuses remain elusive. In our study, we include a total of 411 treatment-naïve CHB patients, among which 43 patients were HBeAg-positive immune-tolerant [IT(e+)], 84 patients were HBeAg-positive immune active [IA(e+)], 65 patients in HBeAg-negative immune active phases [IA(e-)], 149 patients were HBeAg-negative inactive phases [IC(e-)], and 70 patients were in Gray Zone (GZ). HBV RNA was measured in this cohort and its potential correlation with traditional serological markers and liver histopathology were analyzed. Our data showed that HBV RNA was strongly correlated with HBV DNA, HBeAg, HBsAg and ALT. Further subgroup analysis revealed a close correlation between HBV RNA and HBV DNA in patients in the IA (e+) and IA (e-) phases, but neither in IT(e+) nor IC(e-) phase. HBV RNA levels were consistently increased with the advanced degrees of hepatic inflammation, but not hepatic fibrosis. Of note, HBV RNA from HBeAg-positive patients negatively correlated with liver fibrosis, whereas HBV RNA from HBeAg-negative patients was weakly associated with liver inflammation. To sum up, serum HBV RNA shows a distinct profile among CHB patients in different immune statuses and hepatic histopathology stages/grades. Simultaneous testing of HBV RNA and traditional indicators might provide a comprehensive clinical assessment of CHB patients.

Overview of hepatocellular carcinoma: from molecular aspects to future therapeutic options

Hepatocellular carcinoma (HCC) is the seventh most highly prevalent malignant tumor globally and the second most common cause of mortality. HCC develops with complex pathways that occur through multistage biological processes. Non-alcoholic fatty liver disease, metabolic-associated fatty liver disease, alcoholic liver disease, autoimmune hepatitis, hepatitis B, and hepatitis C are the causative etiologies of HCC. HCC develops as a result of epigenetic changes, protein-coding gene mutations, and altered signaling pathways. Biomarkers and potential therapeutic targets for HCC open up new possibilities for treating the disease. Immune checkpoint inhibitors are included in the treatment options in combination with molecular targeted therapy.

Recent advances in understanding T cell activation and exhaustion during HBV infection

Chronic hepatitis B virus (HBV) infection remains a major public health concern globally, and T cell responses are widely believed to play a pivotal role in mediating HBV clearance. Accordingly, research on the characteristics of HBV-specific T cell responses, from activation to exhaustion, has advanced rapidly. Here, we summarize recent developments in characterizing T cell immunity in HBV infection by reviewing basic and clinical research published in the last five years. We provide a comprehensive summary of the mechanisms that induce effective anti-HBV T cell immunity, as well as the latest developments in understanding T cell dysfunction in chronic HBV infection. Furthermore, we briefly discuss current novel treatment strategies aimed at restoring anti-HBV T cell responses.

Hepatitis-B virus: replication cycle, targets, and antiviral approaches

An estimated 257 million people are chronic carriers of hepatitis-B virus (HBV) infection, which resulted in around 1 million deaths, mainly due to hepatocellular carcinoma (HCC). Long-term nucleotide analog treatment of HBV infection is associated with favorable prognosis, no disease progression, and a reduction of HCC risk, but lifelong treatments are required. A better understanding of HBV replication cycle and the host immune response will likely improve the identification of new targets for drug development. Studies are ongoing to determine if it is possible to successfully combine direct-acting antivirals (DAA) with an immunomodulatory therapy to allow increased cure rates. This review will start with summarizing the HBV replication cycle, recall current treatments, and then discuss potential targets and antiviral approaches in development to optimistically reach the HBV cure.