Future Therapy for Hepatitis B Virus: Role of Immunomodulators

Patient Preferences and Their Influence on Chronic Hepatitis B-A Review

Chronic hepatitis B (CHB) is a common chronic viral infectious disease that requires long-term treatment to control the condition and prevent complications. To standardize treatment regimens for CHB, professional associations have established relevant guidelines, but they have often overlooked patient preferences. Historically, in the treatment process, medical decisions were predominantly made by physicians or health care administrators, with limited patient involvement, leading to the neglect of patient preferences. Patient attitudes, expectations, and needs are all influenced by their preferences, and patient preferences have a direct impact on treatment adherence. Understanding and respecting patient preferences are crucial to ensuring treatment effectiveness. This article will explore patient preferences in the treatment of CHB and elucidate the influence of patient preferences on treatment adherence, aiming to provide insights for the development of a more personalized and effective health care process.

Possibility of PD-1/PD-L1 Inhibitors for the Treatment of Patients with Chronic Hepatitis B Infection

BACKGROUND

Chronic hepatitis B (CHB) infection is still a major global public health problem, with nearly two billion patients. Although current antiviral drugs can inhibit viral replication and reduce hepatitis B virus (HBV) related complications, it is difficult to achieve clinical endpoints due to drug resistance.

SUMMARY

Immune checkpoint inhibitors (ICIs) are an important strategy to reverse T-cell exhaustion, and rebuilding an effective functional T-cell response is a promising immunomodulatory approach for CHB patients. However, ICIs may lead to viral reactivation or immune-related adverse effects. There are still many controversies in the application of ICIs in treating patients with CHB.

KEY MESSAGES

This article reviews the research progress of ICIs in CHB infection and related issues. The goal of this paper was to summarize the possible impact of new therapies for CHB with the aim of reducing potential clinical risks.

Targeting TLR9 agonists to secondary lymphoid organs induces potent immune responses against HBV infection

Despite the existence of a prophylactic vaccine against hepatitis B virus (HBV), chronic hepatitis B virus (CHB) infection remains the leading cause of cirrhosis and liver cancer in developing countries. Because HBV persistence is associated with insufficient host immune responses to the infection, development of an immunomodulator as a component of therapeutic vaccination may become an important strategy for treatment CHB. In the present study, we aimed to design a novel immunomodulator with the capacity to subvert immune tolerance to HBV. We developed a lymphoid organ-targeting immunomodulator by conjugating a naturally occurring, lipophilic molecule, α-tocopherol, to a potent CpG oligonucleotide adjuvant pharmacophore. This approach resulted in preferential trafficking of the α-tocopherol-conjugated oligonucleotide to lymphoid organs where it was internalized by antigen-presenting cells (APCs). Moreover, we show that conjugation of the oligonucleotides to α-tocopherol results in micelle-like structure formation, which improved cellular internalization and enhanced immunomodulatory properties of the conjugates. In a mouse model of chronic HBV infection, targeting CpG oligonucleotide to lymphoid organs induced strong cellular and humoral immune responses that resulted in sustained control of the virus. Given the potency and tolerability of an α-tocopherol-conjugated CpG oligonucleotide, this modality could potentially be broadly applied for therapeutic vaccine development.

An in silico study to unveil potential drugs and vaccine chimera for HBV capsid assembly protein: combined molecular docking and dynamics simulation approach

Humans are a major reservoir of the hepatitis B virus (HBV), therefore promising treatment and control vaccination strategies are needed to eradicate the virus. Though promising drugs and vaccines are available against HBV, still efforts are required to enrich the therapy options. Herein, the HBV assembly protein was explored to identify novel targets for future use against HBV. Computer-aided drug designing and immune-informatics techniques were employed for the identification of putative inhibitors and vaccine ensemble against HBV using capsid assembly protein. The identified drug molecule binds with high affinity to the active pocket of the protein, and several epitopes are scanned in the protein sequence. The drug molecule, besides being a good putative inhibitor, has acceptable drug-like properties. A multi-epitope vaccine is also constructed to overcome the limitations of weakly immunogenic epitopes. In contrast to the MHC II level, the set of predicted epitopes has been recognized to interact with significant numbers of HLA alleles of MHC I. Selected epitopes are extremely virulent, antigenic, nontoxic, nonallergic, have suitable affinity to bind with the prevailing DRB*0101 allele, and also spectacle 86% mediocre population coverage. A multi-epitope peptide-based vaccine chimera having 73 amino acids was designed. It emerged as substantially immunogenic, thermally stable, robust in producing cellular as well as humoral immune responses, and had competent physicochemical properties to analyze in vitro and in vivo studies. The capsid assembly protein is a in more stable nature in the presence of the drug molecule compared to the TLR3 receptor in the vaccine presence. These particulars were confirmed by exposing the docked molecules to absolute and relative binding free energy approaches of MMGBSA/PBSA. The purpose to investigate the interactions between the vaccine and a representative TLR3 immune receptor can reveal the intermolecular affinity and possible presentation mechanism of the vaccine by TLR3 to the host immune system. It was revealed that the vaccine is showing a very good affinity of binding for the TLR3 and forming a network of hydrophobic and hydrophilic interactions. Overall, the findings of this study are promising and might be useful for further experimental validations.

Toll-Like Receptor Response to Hepatitis B Virus Infection and Potential of TLR Agonists as Immunomodulators for Treating Chronic Hepatitis B: An Overview

Chronic hepatitis B virus (HBV) infection remains a major global health problem. The immunopathology of the disease, especially the interplay between HBV and host innate immunity, is poorly understood. Moreover, inconsistent literature on HBV and host innate immunity has led to controversies. However, recently, there has been an increase in the number of studies that have highlighted the link between innate immune responses, including Toll-like receptors (TLRs), and chronic HBV infection. TLRs are the key sensing molecules that detect pathogen-associated molecular patterns and regulate the induction of pro- and anti-inflammatory cytokines, thereby shaping the adaptive immunity. The suppression of TLR response has been reported in patients with chronic hepatitis B (CHB), as well as in other models, including tree shrews, suggesting an association of TLR response in HBV chronicity. Additionally, TLR agonists have been reported to improve the host innate immune response against HBV infection, highlighting the potential of these agonists as immunomodulators for enhancing CHB treatment. In this study, we discuss the current understanding of host innate immune responses during HBV infection, particularly focusing on the TLR response and TLR agonists as immunomodulators.

Preferences of Patients with Chronic Hepatitis B - A Discrete Choice Experiment on the Acceptability of Functional Cure

BACKGROUND

Current antiviral therapies for chronic hepatitis B (CHB) rarely achieve functional cure, thus often requiring lifelong therapy. A therapy achieving functional cure in a significant percentage of patients could change the treatment landscape substantially. However, the acceptability of functional cure by patients is unknown, especially if associated with additional treatment burden.

METHODS

A Discrete Choice Experiment (DCE) including patients with CHB was performed between 2018 and 2019 in Germany. Patient inclusion criteria were confirmed CHB; age of at least 18 years; no history of hepatocellular carcinoma; no HIV or HCV/HDV co-infection. The final DCE included the following attributes: route of administration (oral administration by tablets; subcutaneous injection + tablets; intramuscular electroporation + tablets), side effect frequency (0/1/3 days per month), functional cure (1%/30%/50% of patients), frequency of physician visits (monthly, half-yearly) and travel time to treating physician (15/45 min).

RESULTS

The main analysis sample consisted of 108 patients with CHB (mean age: 49.1 years, female: 37.0%, average time since CHB diagnosis: 14.0 years, 52.8% with Hepatitis B surface antigen (HBsAg) chronic HBV infection). High efficacy was found to be the main driver of decisions for/against the presented treatment options (impacted 57% of patients' decisions), followed by therapy regimen (17%), safety profile (12%) and number of physician visits (11%). Latent class analysis revealed first insights into different decision patterns, with age, gender and previous side-effect experience affecting patients' decisions.

CONCLUSION

In comparison to all other treatment-related attributes such as therapy regimen or safety profile, patients with CHB showed a strong preference towards a scenario where a substantial number of patients benefit from sustained disease remission, which mimics functional cure.

Differential Expression of Immune Inhibitory Checkpoint Signatures on Antiviral and Inflammatory T Cell Populations in Chronic Hepatitis B

Virus-specific T cells are critical in mediating the pathogenesis of hepatitis B virus (HBV) infection. Interferon gamma (IFNγ)-producing T cells are associated with resolution; in contrast, interleukin-17 (IL-17)-producing T cells are linked to exacerbation of liver inflammation and injury. Checkpoint receptors stringently regulate T cell functions, with their expression profiles varying on different T cell subsets. Blockade of checkpoint receptors may be an effective therapeutic strategy for chronic hepatitis B (CHB); however, blockade may also inadvertently exacerbate proinflammatory responses. In this study, we sought to determine the balance of inflammatory and antiviral T cells and determine their inhibitory receptor profile. The frequency of total and HBV antigen-specific Th17 and Tc17 cells was higher in CHB patients compared with healthy controls (HCs). Th17 and Tc17 cells in CHB patients had significantly lower expression of T cell immunoglobulin and mucin domain protein-3 (TIM-3) compared with HCs, with no difference in programmed death-1 (PD-1) or CD244 expression. Conversely, Th1 and Tc1 cells in CHB patients hyperexpressed PD-1 and CD244, while TIM-3 expression was comparable in both cohorts. During CHB, antiviral IFNγ T cells hyperexpress multiple immune inhibitory receptors driving their functional impairment. In contrast, inflammatory Th17/Tc17 cells hypoexpress TIM-3, but not PD-1 or CD244. Checkpoint inhibitors for CHB should target PD-1 or CD244 to allow restoration of IFNγ responses without affecting inflammatory IL-17 production.

Screening for hepatitis D and PEG-Interferon over Tenofovir enhance general hepatitis control efforts in Brazil

Background

Hepatitis D virus (HDV), which requires the presence of hepatitis B virus (HBV), is a deadly yet neglected disease that rapidly leads to liver cancer and disease-induced mortality. This co-dependence creates complex transmission dynamics that make it difficult to predict the efficacy of interventions aimed at HBV and/or HDV control in endemic regions, such as certain municipalities of Brazil, where up to 65% of HBV-infected persons are co-infected.

Methodology

We created a mathematical model that captures the joint transmission dynamics of HBV and HDV, incorporating mother-to-child, sexual and household transmission. With an aim to minimize the number of total infections and disease-induced mortality in 2027, we then determined optimal strategies for Brazil and its sub-regions under a constrained budget, which was dynamically allocated among HBV and HDV screening, HBV and HDV treatment, HBV newborn and adult vaccination, and awareness programs. Three treatment options were considered, namely: Tenofovir, PEGylated-Interferon, and nucleic acid polymers (NAP).

Results

The additional cost of HDV screening and the use of a more expensive PEGylated-Interferon are offset by not wasting resources on treating co-infected persons with Tenofovir. The introductory price of NAP treatment must be less than $16,000 per course to become competitive with Tenofovir and PEGylated-Interferon in Brazil.

Conclusion

Additional screening for HDV is beneficial, even in a low HBV and HDV endemic regions of Brazil. We recommend PEGylated-Interferon, wherever possible, for both HBV and HDV. If PEGylated-Interferon is not available in abundance, PEGylated-Interferon for co-infections and 4-year Tenofovir treatment for mono-infections is recommended.

Modulators of innate immunity as novel therapeutics for treatment of chronic hepatitis B

The first line defense mechanisms against viral infection are mediated by the innate immune system. Viral components are detected by infected cells and/or innate immune cells that express different sensory receptors. They in turn mediate induction of direct antiviral mechanisms and further modulation of innate and adaptive immune responses. For evading the innate system, most viruses have evolved efficient mechanisms to block sensing and/or antiviral functions of the innate response. Interestingly, hepatitis B virus (HBV) seems to act like a stealth virus that escapes cell intrinsic antiviral mechanisms through avoiding recognition by the innate system rather than blocking its effector functions. In line with this concept, agonistic activation of innate immunity has emerged as a promising novel anti-HBV therapy approach with several compounds having advanced to the clinical stage.

Drugs in Development for Hepatitis B

With high morbidity and mortality worldwide, there is great interest in effective therapies for chronic hepatitis B (CHB) virus. There are currently several dozen investigational agents being developed for treatment of CHB. They can be broadly divided into two categories: (1) direct-acting antivirals (DAAs) that interfere with a specific step in viral replication; and (2) host-targeting agents that inhibit viral replication by modifying host cell function, with the latter group further divided into the subcategories of immune modulators and agents that target other host functions. Included among the DAAs being developed are RNA interference therapies, covalently closed circular DNA (cccDNA) formation and transcription inhibitors, core/capsid inhibitors, reverse transcriptase inhibitors, hepatitis B surface antigen (HBsAg) release inhibitors, antisense oligonucleotides, and helioxanthin analogues. Included among the host-targeting agents are entry inhibitors, cyclophilin inhibitors, and multiple immunomodulatory agents, including Toll-like receptor agonists, immune checkpoint inhibitors, therapeutic vaccines, engineered T cells, and several cytokine agents, including recombinant human interleukin-7 (CYT107) and SB 9200, a novel therapy that is believed to both have direct antiviral properties and to induce endogenous interferon. In this review we discuss agents that are currently in the clinical stage of development for CHB treatment as well as strategies and agents currently at the evaluation and discovery phase and potential future targets. Effective approaches to CHB may require suppression of viral replication combined with one or more host-targeting agents. Some of the recent research advances have led to the hope that with such a combined approach we may have a functional cure for CHB in the not distant future.

Application of viromics: a new approach to the understanding of viral infections in humans

This review is focused at exploring the strengths of modern technology driven data compiled in the areas of virus gene sequencing, virus protein structures and their implication to viral diagnosis and therapy. The information for virome analysis (viromics) is generated by the study of viral genomes (entire nucleotide sequence) and viral genes (coding for protein). Presently, the study of viral infectious diseases in terms of etiopathogenesis and development of newer therapeutics is undergoing rapid changes. Currently, viromics relies on deep sequencing, next generation sequencing (NGS) data and public domain databases like GenBank and unique virus specific databases. Two commonly used NGS platforms: Illumina and Ion Torrent, recommend maximum fragment lengths of about 300 and 400 nucleotides for analysis respectively. Direct detection of viruses in clinical samples is now evolving using these methods. Presently, there are a considerable number of good treatment options for HBV/HIV/HCV. These viruses however show development of drug resistance. The drug susceptibility regions of the genomes are sequenced and the prediction of drug resistance is now possible from 3 public domains available on the web. This has been made possible through advances in the technology with the advent of high throughput sequencing and meta-analysis through sophisticated and easy to use software and the use of high speed computers for bioinformatics. More recently NGS technology has been improved with single-molecule real-time sequencing. Here complete long reads can be obtained with less error overcoming a limitation of the NGS which is inherently prone to software anomalies that arise in the hands of personnel without adequate training. The development in understanding the viruses in terms of their genome, pathobiology, transcriptomics and molecular epidemiology constitutes viromics. It could be stated that these developments will bring about radical changes and advancement especially in the field of antiviral therapy and diagnostic virology.

Interleukin-34 inhibits hepatitis B virus replication in vitro and in vivo

Background

The hepatitis B virus (HBV) infection could activate the immune system and induce extensive inflammatory response. As the most important inflammatory factor, interleukins are critical for anti-viral immunity. Here we investigated whether interleukin-34 (IL-34) play a role in HBV infection.

Methodology/Principal findings

In this study, we first found that both serum IL-34 and IL-34 mRNA in PBMCs in chronic HBV patients was significantly decreased compared to the healthy controls. Furthermore, both IL-34 protein and mRNA levels were declined hepatoma cells expressing HBV. In addition, the clinical parameters analysis found that serum IL-34 was significantly associated with HBV DNA (P = 0.0066), ALT (P = 0.0327), AST (P = 0.0435), TB (P = 0.0406), DB (P = 0.0368) and AFP (P = 0.0225). Correlation analysis also found that serum IL-34 negatively correlated with HBV DNA copies, ALT and AST. In vitro studies found that IL-34 treatment in HepAD38 and HepG2.2.15 cells markedly inhibited HBV DNA, total RNA, 3.5kb mRNA and HBc protein. In vivo studies further demonstrated IL-34 treatment in HBV transgenic mice exhibited greater inhibition on HBV DNA, total RNA, 3.5kb mRNA and HBc protein, suggesting the effect to IL-34 on HBV is likely due to host innate or adaptive immune response.

Conclusions/Significance

Our study identified a novel interleukin, IL-34, which has anti-viral activity in HBV replication in hepatocytes in vitro and in vivo. These data suggest a rationale for the use of IL-34 in the HBV treatment.

Treatment of hepatitis B virus with combination therapy now and in the future

Chronic Hepatitis B continues as a significant public health problem despite the availability of safe and effective antivirals and a highly effective protective vaccine. Current therapy, however rarely leads to cure and lifelong therapy is often required, contributing to poor uptake and ongoing morbidity. New insights into the hepatitis B viral life cycle and the host immune response have expanded the potential targets for drug therapies with interesting antiviral candidates and novel immunotherapeutic approaches in early stage development. Yet, HBV persistence is multifactorial - due to an intrahepatic reservoir and ongoing HBV-mediated immune dysregulation, making "cure" unlikely to be realized through even the most efficacious monotherapy. Building on the success seen in the treatment of hepatitis C (HCV) and human immunodeficiency virus (HIV), combination therapy may be an essential strategy to improve efficacy and decrease viral breakthrough. Combinations acting on immune and viral targets are particularly attractive. However, creating synergy while balancing efficacy and safety remains a clear challenge. Various approaches to combination therapy are reviewed, highlighting strengths and challenges of each potential strategy. Overall, combination therapies are attractive as the next step towards cure and are a key strategy for achieving treatment with finite durations and durable endpoints.

Tenofovir alafenamide for the treatment of chronic hepatitis B virus infection

INTRODUCTION

In April 2017 tenofovir alafenamide (TAF) was added to the list of first-line therapies recommended for chronic hepatitis B (CHB). TAF has pharmacology similar to tenofovir disoproxil fumarate (TDF) with higher cell delivery to the hepatocytes but less systemic exposure. Areas covered: We review here studies leading to TAF's approval and comparing it to TDF. In two major clinical trials, TAF was non-inferior to TDF in achieving HBV DNA levels below 29 IU/ml. TAF-treated patients had significantly smaller decreases in bone mineral density (BMD) at the hip and spine in both HBeAg-positive and HBeAg-negative patients, and smaller mean increases in serum creatinine, although the difference was only statistically significant in HBeAg-positive patients. Patients treated with TDF for 96 weeks and then switched to TAF had improvements in renal and BMD measures only 24 weeks after switching. Expert commentary: With clear evidence from major studies showing that TAF is safe, tolerable, and non-inferior to TDF, its recommendation as a first-line therapy is appropriate. Longer term follow up will be required to determine if the differences in adverse bone and kidney effects seen with TAF in comparison to TDF will be clinically relevant.

Review. Development, Applications, Benefits, Challenges and Limitations of the New Genome Engineering Technique. An Update Study

We assume that the CRISPR Cas9 theory must be delimited by applicability, because the consequences of long term DNA manipulation remain unknown. Moreover, the irreversibility of this procedure should instigate researchers to reserved opinions.

Usefulness as well as benefits of CRISPR Cas9 made it one of the most popular and used genome editing technique. But with its huge potential, ethical and safety concerns emerge. Therefore, before continuing research in this direction we should have a well organized system that is able to make that differentiation between research and reproduction. However we truly believe in the future of genetic engineering and with the CRISPR-Cas9 system we expect that the opportunity of treating now so called incurable diseases arises. Time is all we need.