Hepatitis B Virus DNA Integration and Clonal Expansion of Hepatocytes in the Chronically Infected Liver

Epidemiological, diagnostic, therapeutic and prognostic impact of hepatitis B and D virus infection on hepatocellular carcinoma: A review of the literature

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for >90% of primary liver cancer cases, and chronic infections with hepatitis B virus (HBV) and hepatitis D virus (HDV) are major contributors.

METHODS

A comprehensive literature review was conducted using the MEDLINE (PubMed) database, focusing on studies related to HBV, HDV, and HCC.

RESULTS

HBV contributes to HCC through mechanisms like viral integration into the host genome, chronic inflammation, and immune modulation, leading to genomic instability and altered cell signaling. HDV exacerbates HBV-induced liver damage, accelerating fibrosis and cirrhosis, and significantly increasing HCC risk. Antiviral therapies and vaccinations have majorly reduced the burden of HBV-related HCC, but HDV remains challenging to treat due to limited therapeutic options. Emerging treatments like Bulevirtide showed promising results.

CONCLUSION

This review highlights the critical impact of HBV and HDV co-infections on HCC development, emphasizing the need for more effective therapeutic strategies. While advances in antiviral therapies have reduced the incidence of HBV-related HCC, the high burden of HDV-related complications persists. Future research should focus on improving treatments for HDV and understanding its unique contribution to HCC pathogenesis.

Tumor-associated macrophages and CD8+ T cells: dual players in the pathogenesis of HBV-related HCC

HBV infection is a key risk factor for the development and progression of hepatocellular carcinoma (HCC), a highly invasive tumor, and is characterized by its persistent immunosuppressive microenvironment. This review provides an in-depth analysis of HBV-related HCC and explores the interactions between neutrophils, natural killer cells, and dendritic cells, examining their roles in regulating tumor-associated macrophages and CD8+ T cells and shaping the tumor microenvironment. Two critical players in the immunosuppressive milieu of HBV-related HCC are CD8+ T cells and tumor-associated macrophages (TAMs). The study explores how TAMs, initially recruited to combat infection, transform, adopting a tumor-promoting phenotype, turning against the body, promoting tumor cell proliferation, suppressing anti-tumor immunity, and assisting in the spread of cancer. Meanwhile, CD8+ T cells, crucial for controlling HBV infection, become dysfunctional and exhausted in response to persistent chronic viral inflammation. The review then dissects how TAMs manipulate this immune response, further depleting CD8+ T cell functions through mechanisms like arginine deprivation and creating hypoxic environments that lead to exhaustion. Finally, it explores the challenges and promising therapeutic avenues that target TAMs and CD8+ T cells, either separately or in combination with antiviral therapy and personalized medicine approaches, offering hope for improved outcomes in HBV-related HCC.

Genetically-modified, redirected T cells target hepatitis B surface antigen-positive hepatocytes and hepatocellular carcinoma lesions in a clinical setting

BACKGROUND/AIMS

Hepatitis B virus (HBV)-DNA integration in HBV-related hepatocellular carcinoma (HBV-HCC) can be targeted by HBV-specific T cells. SCG101 is an autologous, HBV-specific T-cell product expressing a T-cell receptor (TCR) after lentiviral transduction recognizing the envelope-derived peptide (S20-28) on HLA-A2. We here validated its safety and efficacy preclinically and applied it to an HBV-related HCC patient (NCT05339321).

METHODS

Good Manufacturing Practice-grade manufactured cells were assessed for off-target reactivity and functionality against hepatoma cells. Subsequently, a patient with advanced HBV-HCC (Child-Pugh class A, Barcelona Clinic Liver Cancer stage B, Eastern Cooperative Oncology Group performance status 0, hepatitis B e antigen-, serum hepatitis B surface antigen [HBsAg]+, HBsAg+ hepatocytes 10%) received 7.9×107 cells/kg after lymphodepletion. Safety, T-cell persistence, and antiviral and antitumor efficacy were evaluated.

RESULTS

SCG101, produced at high numbers in a closed-bag system, showed HBV-specific functionality against HBV-HCC cells in vitro and in vivo. Clinically, treatment was well tolerated, and all adverse events, including transient hepatic damage, were reversible. On day 3, ALT levels increased to 1,404 U/L, and concurrently, serum HBsAg started decreasing by 3.84 log10 and remained <1 IU/mL for over six months. HBsAg-expressing hepatocytes in liver biopsies were undetectable after 73 days. The patient achieved a partial response according to modified RECIST with a >70% reduction in target lesion size. Transferred T cells expanded, developed a stem cell-like memory phenotype, and were still detectable after six months in the patient's blood.

CONCLUSION

SCG101 T-cell therapy showed encouraging efficacy and safety in preclinical models and in a patient with primary HBV-HCC and concomitant chronic hepatitis B with the capability to eliminate HBsAg+ cells and achieve sustained tumor control after single dosing.

Are There More Human Cancer Viruses Left to Be Found?

Of the thousands of viruses infecting humans, only seven cause cancer in the general population. Tumor sequencing is now a common cancer medicine procedure, and so it seems likely that more human cancer viruses already would have been found if they exist. Here, we review cancer characteristics that can inform a dedicated search for new cancer viruses, focusing on Kaposi sarcoma herpesvirus and Merkel cell polyomavirus as the most recent examples of successful genomic and transcriptomic searches. We emphasize the importance of epidemiology in determining which cancers to examine and describe approaches to virus discovery. Barriers to virus discovery, such as novel genomes and viral suppression of messenger RNA expression, may exist that prevent virus discovery using existing approaches. Optimally virus hunting should be performed in such a way that if no virus is found, the tumor can be reasonably excluded from having an infectious etiology and new information about the biology of the tumor can be found.

Detection of HBV DNA integration in plasma cell-free DNA of different HBV diseases utilizing DNA capture strategy

The landscape of hepatitis B virus (HBV) integration in the plasma cell-free DNA (cfDNA) of HBV-infected patients with different stages of liver diseases [chronic hepatitis B (CHB), liver cirrhosis (LC), and hepatocellular carcinoma (HCC)] remains unclear. In this study, we developed an improved strategy for detecting HBV DNA integration in plasma cfDNA, based on DNA probe capture and next-generation sequencing. Using this optimized strategy, we successfully detected HBV integration events in chimeric artificial DNA samples and HBV-infected HepG2-NTCP cells at day one post infection, with high sensitivity and accuracy. The characteristics of HBV integration events in the HBV-infected HepG2-NTCP cells and plasma cfDNA from HBV-infected individuals (CHB, LC, and HCC) were further investigated. A total of 112 and 333 integration breakpoints were detected in the HepG2-NTCP cells and 22 out of 25 (88%) clinical HBV-infected samples, respectively. In vivo analysis showed that the normalized number of support unique sequences (nnsus) in HCC was significantly higher than in CHB or LC patients (P values ​< ​0.05). All integration breakpoints are randomly distributed on human chromosomes and are enriched in the HBV genome around nt 1800. The majority of integration breakpoints (61.86%) are located in the gene-coding region. Both non-homologous end-joining (NHEJ) and microhomology-mediated end-joining (MMEJ) interactions occurred during HBV integration across the three different stages of liver diseases. Our study provides evidence that HBV DNA integration can be detected in the plasma cfDNA of HBV-infected patients, including those with CHB, LC, or HCC, using this optimized strategy.

Hepatitis B virus DNA integration: Implications for diagnostics, therapy, and outcome

Hepatitis B virus (HBV) DNA integration - originally recognised as a non-functional byproduct of the HBV life cycle - has now been accepted as a significant contributor to HBV pathogenesis and hepatitis D virus (HDV) persistence. Integrated HBV DNA is derived from linear genomic DNA present in viral particles or produced from aberrantly processed relaxed circular genomic DNA following an infection, and can drive expression of hepatitis B surface antigen (HBsAg) and HBx. DNA integration events accumulate over the course of viral infection, ranging from a few percent during early phases to nearly 100 percent of infected cells after prolonged chronic infections. HBV DNA integration events have primarily been investigated in the context of hepatocellular carcinoma development as they can activate known oncogenes and other growth promoting genes, cause chromosomal instability and, presumably, induce epigenetic alterations, promoting tumour growth. More recent evidence suggests that HBsAg expression from integrated DNA might contribute to HBV pathogenesis by attenuating the immune response. Integrated DNA provides a source for envelope proteins required for HDV replication and hence represents a means for HDV persistence. Because integrated DNA is responsible for persistence of HBsAg in the absence of viral replication it impacts established criteria for the resolution of HBV infection, which rely on HBsAg as a diagnostic marker. Integrated HBV DNA has been useful in assessing the turnover of infected hepatocytes which occurs during all phases of chronic hepatitis B including the initial phase of infection historically termed immune tolerant. HBV DNA integration has also been shown to impact the development of novel therapies targeting viral RNAs.

Long-term antiviral therapy is associated with changes in the profile of transcriptionally active HBV integration in the livers of patients with CHB

Hepatitis B virus (HBV) integration exists throughout the clinical course of chronic hepatitis B (CHB). This study investigated the effects of long-term antiviral therapy on the level and profiles of transcriptionally active HBV integration. Serial liver biopsies and paired blood samples were obtained from 16, 16, and 22 patients with CHB at baseline, 78, and 260 weeks of entecavir monotherapy or combined with pegylated interferon alfa, respectively. Serum HBV biomarkers were longitudinally assessed. RNA-seq and HIVID2 program was used to identify HBV-host chimeric RNAs transcribed from integrated DNA. The counts of HBV integration reads were positively related to both serum HBV DNA levels (r = 0.695, p = 0.004) and HBeAg titers (r = 0.724, p = 0.021) at baseline, but the positive correlation exited only to the serum HBsAg levels after 260 weeks of antiviral therapy (r = 0.662, p = 0.001). After 78 weeks of antiviral therapy, the levels of HBV integration expression decreased by 12.25 folds from baseline. The viral junction points were enriched at the S and HBx genes after the long-term antiviral therapy. HBs-FN1 became one of the main transcripts, with the mean proportion of HBs-FN1 in all integrated expression increased from 2.79% at baseline to 10.54% at Week 260 of antiviral treatment. Antiviral therapy may reduce but not eliminate the HBV integration events and integration expression. Certain integration events, such as HBs-FN1 can persist in long-term antiviral treatment.

Expression and purification of Hepatitis B virus core antigen using Escherichia coli and its utilization for the diagnosis of Hepatitis B virus infections

Hepatitis B virus (HBV) is responsible for most of the viral hepatitis worldwide. HBV is a partially double stranded DNA virus that is composed of four main open reading frames (ORFs) encoding its important antigens, namely hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg), HBV polymerase and hepatitis B X antigen (HBxAg). In this study, we report a successful method for the cloning and expression of HBcAg. The ORF of HBcAg was successfully amplified using polymerase chain reaction (PCR), cloned into the expression vector pRSET-B and transformed to Escherichia coli (E. coli) BL-21 (DE3) pLysS strain for protein expression. Successful expression of HBcAg was accomplished, in which an induced protein with a molecular weight of 24 kDa was obtained and confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. The produced HBcAg was successfully used for the diagnosis of HBV infected patient through detection of antibodies against HBcAg (anti-HBcAg) in the serum of the patient utilizing Western blotting. Overall, this study provides a simple, convenient and efficient protocol for the production of HBcAg that can be used as an important candidate to study the diagnosis and prognosis of HBV disease, as well as for understanding the epidemiological prevalence of HBV cases and production of anti-HBcAg.

The Initial Hepatitis B Virus-Hepatocyte Genomic Integrations and Their Role in Hepatocellular Oncogenesis

Hepatitis B virus (HBV) remains a dominant cause of hepatocellular carcinoma (HCC). Recently, it was shown that HBV and woodchuck hepatitis virus (WHV) integrate into the hepatocyte genome minutes after invasion. Retrotransposons and transposable sequences were frequent sites of the initial insertions, suggesting a mechanism for spontaneous HBV DNA dispersal throughout the hepatocyte genome. Several somatic genes were also identified as early insertional targets in infected hepatocytes and woodchuck livers. Head-to-tail joints (HTJs) dominated amongst fusions, indicating their creation by non-homologous end-joining (NHEJ). Their formation coincided with the robust oxidative damage of hepatocyte DNA. This was associated with the activation of poly(ADP-ribose) polymerase 1 (PARP1)-mediated dsDNA repair, as reflected by the augmented transcription of PARP1 and XRCC1; the PARP1 binding partner OGG1, a responder to oxidative DNA damage; and increased activity of NAD+, a marker of PARP1 activation, and HO1, an indicator of cell oxidative stress. The engagement of the PARP1-mediated NHEJ repair pathway explains the HTJ format of the initial merges. The findings show that HBV and WHV are immediate inducers of oxidative DNA damage and hijack dsDNA repair to integrate into the hepatocyte genome, and through this mechanism, they may initiate pro-oncogenic processes. Tracking initial integrations may uncover early markers of HCC and help to explain HBV-associated oncogenesis.

Novel fully automated prototype assays for specific detection of phosphorylated and non-phosphorylated Hepatitis B core antigens

BACKGROUND

Hepatitis B core antigen (HBcAg) has been proposed as a surrogate marker to reflect transcriptional activity of HBV covalently closed circular DNA (cccDNA) during active infections and may be a valuable tool to monitor the efficacy of antiviral therapies. However, HBcAg-specific immunoassays are unavailable, and current assays that measure hepatitis B core-related antigen (HBcrAg) cannot distinguish between HBcAg, HBeAg, and precore (PreC) proteins.

OBJECTIVE

Two fully automated assays were developed to specifically detect phosphorylated HBcAg (P-HBcAg, representing non-HBV DNA-containing particles) and non-phosphorylated HBcAg (representing HBV DNA-containing particles) circulating in HBV infected patients.

STUDY DESIGN

P-HBcAg and HBcAg levels were analyzed in 124 single timepoint patients with active infections, in three longitudinal specimens from patients with acute HBV infections, and in four chronic hepatitis B (CHB) patients on-therapy (TDF - tenofovir disoproxil fumarate, pegIFN - pegylated interferon, NAPs - nucleic acids polymers).

RESULTS

Analyzing acute infections revealed that P-HBcAg and HBcAg levels correlate more closely than HBcrAg to HBV DNA. During antiviral treatment of CHB patients, HBcAg correlates well with HBV DNA and indicates a therapeutic response to the treatment at the beginning of the therapy. In contrast, P-HBcAg tracks more closely to HBV RNA. Importantly, P-HBcAg is detectable several months after HBcAg became undetectable indicating that cccDNA is still transcriptionally active in hepatocytes.

CONCLUSIONS

Overall, the ability to specifically distinguish between the various states of HBcAg (phosphorylated and non-phosphorylated) can provide additional insights for disease staging, drug development, and management of HBV therapies.

Clinical Distribution Characteristics and Identification for Significant Liver Inflammation of Patients in Chronic Hepatitis B with Indeterminate Phase

Aim

In clinical practice, a considerable proportion of patients with chronic hepatitis B (CHB) who do not conform to any immune status are considered to be in the "indeterminate phase". In this study, we aim to study the clinical distribution characteristics and identification of significant liver inflammation in patients in indeterminate phase.

Methods

This study retrospectively analyze clinical data of 1226 patients with CHB at two medical centers in Zhejiang province. According to American Association for the Study of Liver Diseases (AASLD) 2018 hepatitis B guidance, CHB can be divided into four phases: immune-tolerant phase, HBeAg-positive immune active phase, inactive phase, and HBeAg-negative immune active phase. Liver inflammation grade was evaluated using the Scheuer scoring system, and significant liver inflammation was defined as G ≥ 2.

Results

The distribution of different immune status was as follows: 259 (21.1%) patients in immune-tolerant phase, 365 (29.8%) patients in HBeAg-positive immune active phase, 128 (10.4%) patients in inactive phase, and 33 (2.7%) patients in HBeAg-negative immune active phase. However, 441 (36.0%) patients did not meet any of the above immune phases, which were defined as indeterminate phase. Significant liver inflammation (54.1%) was common in CHB patients with indeterminate phase. Prothrombin time (PT), platelet count (PLT), alanine aminotransferase (ALT), and hepatitis B virus (HBV)-DNA were associated with significant inflammation.

Conclusions

The results of this study showed that about 36.0% of patients were divided into indeterminate phase. The proportion of patients with significant inflammation in indeterminate phase and liver inflammation becomes more severe with aggravation of fibrosis stage. PT, PLT, ALT, and HBV-DNA may have a significant correlation with severe inflammation and prognosis of CHB.

A nomogram based on HBeAg, AST, and age to predict non-minimal liver inflammation in CHB patients with ALT <80 U/L

Objective

Precise assessment of liver inflammation in untreated hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B virus (HBV) infection can determine when to initiate antiviral therapy. The aim of this study was to develop and validate a nomogram model for the prediction of non-minimal liver inflammation based on liver pathological injuries combined with age and alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatitis B surface antigen (HBsAg), HBeAg, and HBV DNA quantification.

Methods

We retrospectively included 735 HBeAg-positive chronic hepatitis B (CHB) patients with ALT < 80 U/L as the primary cohort and prospectively enrolled 196 patients as the validation cohort. Multivariate logistic regression analysis identified independent impact factors. A nomogram to predict significant liver inflammation was developed and validated.

Results

Multivariate logistic regression analysis showed that HBeAg, AST, and age were independent risk factors for predicting non-minimal liver inflammation in untreated CHB patients. The final formula for predicting non-minimal liver inflammation was Logit(P) = -1.99 - 0.68 × Log₁₀HBeAg + 0.04 × Age + 0.06 × AST. A nomogram for the prediction of non-minimal liver inflammation was established based on the results from the multivariate analysis. The predicted probability of the model being consistent with the actual probability was validated by the calibration curves, showing the best agreement in both the primary and validation cohorts. The C-index was 0.767 (95%CI = 0.734-0.802) in the primary cohort and 0.749 (95%CI = 0.681-0.817) in the prospective validation cohort.

Conclusions

The nomogram based on HBeAg, AST, and age might help predict non-minimal liver inflammation in HBeAg-positive CHB patients with ALT < 80 U/L, which is practical and easy to use for clinicians.

Hepatitis B Virus DNA Integration Drives Carcinogenesis and Provides a New Biomarker for HBV-related HCC

Hepatitis B virus (HBV) DNA integration is an incidental event in the virus replication cycle and occurs in less than 1% of infected hepatocytes during viral infection. However, HBV DNA is present in the genome of approximately 90% of HBV-related HCCs and is the most common somatic mutation. Whole genome sequencing of liver tissues from chronic hepatitis B patients showed integration occurring at random positions in human chromosomes; however, in the genomes of HBV-related HCC patients, there are integration hotspots. Both the enrichment of the HBV-integration proportion in HCC and the emergence of integration hotspots suggested a strong positive selection of HBV-integrated hepatocytes to progress to HCC. The activation of HBV integration hotspot genes, such as telomerase (TERT) or histone methyltransferase (MLL4/KMT2B), resembles insertional mutagenesis by oncogenic animal retroviruses. These candidate oncogenic genes might shed new light on HBV-related HCC biology and become targets for new cancer therapies. Finally, the HBV integrations in individual HCC contain unique sequences at the junctions, such as virus-host chimera DNA (vh-DNA) presumably being a signature molecule for individual HCC. HBV integration may thus provide a new cell-free tumor DNA biomarker to monitor residual HCC after curative therapies or to track the development of de novo HCC.

Perspectives on current controversial issues in the management of chronic HBV infection

Clinical and basic research in the past decades has achieved consensus in the understanding of chronic hepatitis B virus (HBV) infection and the management of chronic hepatitis B and HBV-cirrhosis. However, debatable challenges to the existing consensus in the concept and/or definitions have emerged. These include (1). alanine aminotransferase upper limit of normal: traditional laboratory-defined vs fixed; (2). nomenclature for phases of chronic HBV infection: classical vs EASL proposal; (3). indication of antiviral therapy: to treat patients vs to treat HBV; (4). finite vs indefinite long-term antiviral therapy: A. finite therapy in HBV-cirrhosis; B. retreatment decision: biochemical markers vs HBsAg/ALT kinetics. The pros and cons of these controversial issues were reviewed, assessed, and discussed in depth based on relevant lines of scientific evidence, intended to clarify or solve these controversial issues.

Analysis of S gene characteristic sequences and changes in properties of protein expression in HBV ASCs with low-level HBsAg

Objective

We detected the serum HBsAg immune complex (HBsAg-CIC) and sequenced the HBV S gene in these patients to reveal the association between sustained low-level expression of HBsAg and mutated S gene sequence characteristics, protein function changes, and HBsAg immune complex formation.

Methods

A total of 204 samples were collected and divided into high-level (n = 60, HBsAg level >10 IU/ml) and low-level (n = 144, HBsAg level ≤ 10 IU/ml) HBsAg groups. The clinical and epidemiological data of the two groups were statistically compared. According to different serological patterns and genotypes, the HBsAg-CIC results of the high-level and low-level HBsAg groups were divided into different subgroups, and then the HBsAg-CIC positive rates among different subgroups were compared. We sequenced the S gene of HBV from the two groups and identified the relevant mutations in the MHR of the S gene. In addition, we compared the changes in HBsAg protein properties and functions after hot spot mutation in the MHR of the S gene.

Results

Comparing the positive rates of HBsAg-CIC under different serological patterns and genotypes in the two groups, the HBsAg-CIC positive rate was higher in the low-level HBsAg group. Moreover, there was weak correlation between HBsAg-CIC and HBsAg or HBV DNA in both groups (r = 0.32, 0.27, 0.41, 0.48; P < 0.05). Sequencing of S gene in the two groups, showed that the hot-spot mutations were T126A, M133L/T/S, and F134L/T/I in MHR of S gene of genotype B, and hot-spot mutations were Q101R and I126S/T in MHR of S gene of genotype C. Additionally, the positive rate of MHR mutation in the S gene from HBsAg-CIC positive patients was higher in the low-level HBsAg group.

Conclusion

The host immune process of clearing HBV seems to have multiple site mutations in MHR, which changes the physicochemical properties and functions of HBsAg and intensifies the formation of HBsAg-CIC, thus avoiding the effective recognition of HBsAg by the host and resulting in immune tolerance between the host and HBV, which may be one of the formation mechanisms of sustained low-level expression of HBsAg in the serum of HBV-infected persons.

Hepatitis B x (HBx) as a Component of a Functional Cure for Chronic Hepatitis B

Patients who are carriers of the hepatitis B virus (HBV) are at high risk of chronic liver disease (CLD) which proceeds from hepatitis, to fibrosis, cirrhosis and to hepatocellular carcinoma (HCC). The hepatitis B-encoded X antigen, HBx, promotes virus gene expression and replication, protects infected hepatocytes from immunological destruction, and promotes the development of CLD and HCC. For virus replication, HBx regulates covalently closed circular (ccc) HBV DNA transcription, while for CLD, HBx triggers cellular oxidative stress, in part, by triggering mitochondrial damage that stimulates innate immunity. Constitutive activation of NF-κB by HBx transcriptionally activates pro-inflammatory genes, resulting in hepatocellular destruction, regeneration, and increased integration of the HBx gene into the host genome. NF-κB is also hepatoprotective, which sustains the survival of infected cells. Multiple therapeutic approaches include direct-acting anti-viral compounds and immune-stimulating drugs, but functional cures were not achieved, in part, because none were yet devised to target HBx. In addition, many patients with cirrhosis or HCC have little or no virus replication, but continue to express HBx from integrated templates, suggesting that HBx contributes to the pathogenesis of CLD. Blocking HBx activity will, therefore, impact multiple aspects of the host–virus relationship that are relevant to achieving a functional cure.

Identification of Warning Transition Points from Hepatitis B to Hepatocellular Carcinoma Based on Mutation Accumulation for the Early Diagnosis and Potential Drug Treatment of HBV-HCC

The accumulation of multiple genetic mutations is essential during the occurrence and development of hepatocellular carcinoma induced by hepatitis B (HBV-HCC), but understanding their cooperative effects and identifying the warning transition point from hepatitis B to HCC are challenges. In the genomic analysis of somatic mutations of the patient with HBV-HCC in a patient-specific protein-protein interaction (ps-PPI) network, we find mutation influence can propagate along the ps-PPI network. Therefore, in the article, we got the mutation cluster as a new research unit using the Random Walks with Restarts algorithm that is used to describe the efficient boundary of mutation influences. The connection of mutation cluster leads to dysregulation of signaling pathways corresponding to HCC, while dysregulated signaling pathways accumulate gradually and experience a process from quantitative to qualitative changes including a critical mutation cluster called transition point (TP) from hepatitis B to HCC. Moreover, two subtypes of HCC patients with different prognosis and their corresponding biological and clinical characteristics were identified according to TP. The poor prognosis HCC subtype was associated with significant metabolic pathway dysregulation and lower immune cell infiltration, while we also identified several preventive drugs to block the transformation of hepatitis B to hepatocellular carcinoma. The network-level study integrated multiomics data not only showed the sequence of multiple somatic mutations and their cooperative effect but also identified the warning transition point in HCC tumorigenesis for each patient. Our study provides new insight into exploring the cooperative molecular mechanism of chronic inflammatory malignancy in the liver and lays the foundation for the development of new approaches for early prediction and diagnosis of hepatocellular carcinoma and personalized targeted therapy.

Assessing immunological and virological responses in the liver: implications for the cure of chronic hepatitis B virus infection

Cure from chronic HBV infection is rare with current therapies. Basic research has helped to fundamentally improve our knowledge of the viral life cycle and virus-host interactions, and provided the basis for several novel drug classes that are currently being developed or are being tested in clinical trials. While these novel compounds targeting the viral life cycle or antiviral immune responses hold great promise, we are still lacking a comprehensive understanding of the immunological and virological processes that occur at the site of infection, the liver. At the International Liver Congress 2021 (ILC 2021), a research think tank on chronic HBV infection focused on mechanisms within the liver that facilitate persistent infection and looked at the research questions that need to be addressed to fill knowledge gaps and identify novel therapeutic strategies. Herein, we summarise the discussion by the think tank and identify the key basic research questions that must be addressed in order to develop more effective strategies for the functional cure of HBV infection.

Targeted long-read sequencing reveals clonally expanded HBV-associated chromosomal translocations in patients with chronic hepatitis B

Background & Aims

Methods

Results

Conclusions

Lay summary

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Fresh frozen liver biopsies from patients with CHB were subjected to targeted long-read RNA and DNA sequencing.

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Inter-chromosomal translocations associated with HBV integration events detected in one-third of patients.

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Chromosomal translocations were unique to each biopsy sample, suggesting that each originated randomly.

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A larger fraction of the HBV transcriptome originates from cccDNA in patients who are HBeAg-positive.

Significant metabolic alterations in patients with hepatitis B virus replication observed via serum untargeted metabolomics shed new light on hepatitis B virus infection

Until now, the metabolic effects of hepatitis B virus (HBV) replication on the progression of hepatic diseases (hepatitis, cirrhosis, and liver cancer) and liver functions have remained unexplored. Thus, a total of 199 hepatic disease patients with active and inactive HBV were enrolled in this study to explore serum metabolic characteristics using untargeted metabolomics. Multiple analyses, including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), volcano plot and pathway analysis, were used for metabolic data analysis. Additionally, differential metabolites were analysed by commercial databases. A decrease of approximately 0.8-fold in amino acids (L-glutamic acid, D-glutamine and L-tyrosine) and an increase of 2-fold in phosphatidylcholines (PCs) and lysophosphatidylcholines (LPCs) were observed in hepatic disease patients with HBV replication. Moreover, downregulation of arachidonic acid, PC 34:2, sn-glycerol-3-phosphocholine, 1-palmitoylglycerophosphoinositol, and 1-oleoylglycerophosphoinositol by 0.6-fold was also found in the serum of patients with HBV replication. In addition, liver function was significantly different between cirrhosis patients with or without HBV replication (p < .05). In summary, this is the first study to focus on the metabolic changes induced by HBV replication in patients and to compare metabolic alterations in the progression of hepatic disease induced by HBV infection. High levels of amino acid depletion and PC and LPC biosynthesis were primarily observed, which may shed new light on the pathogenesis and treatment of HBV infection.

Huge solitary necrotic nodule of the liver: a rare case report with review of literature

Solitary necrotic nodule of the liver (SNNL) is an uncommon disease in clinical practice, and its pathogenesis is still unclear. Here, we report the case of a 35-year-old woman. After physical examination, the patient was found to have a liver neoplasm, and there were no other physical complaints. Abdominal contrast-enhanced computed tomography (CT) showed the presence of a hypodense lesion. The patient opted for surgery to eliminate the lesion. Pathologic examination revealed an isolated necrotic nodular lesion with a size of 12 cm×10 cm×10 cm. The patient had a history of hepatitis B infection. To our knowledge, this is the largest SNNL ever reported and the first case with a history of hepatitis B infection.

Current Perspectives on B Lymphocytes in the Immunobiology of Hepatocellular Carcinoma

Immune cells infiltrating tumors are capable of significantly impacting carcinogenesis through cancer promotion and anticancer responses. There are many aspects of hepatocellular carcinoma (HCC) related T lymphocytes that are undergoing extensive studies, whereas the effect exerted by B lymphocytes remains a less researched area. In this study, the latest research on the effect of B lymphocytes as they infiltrate tumors in relation to HCC is presented. Their prognosis-related importance is analyzed, along with their function in the tumor microenvironment (TME), as well as the way that B cell biology can be employed to help create a B cell therapy strategy for HCC.

Modeling reveals no direct role of the extent of HBV DNA integrations on the outcome of infection

Hepatitis B virus (HBV) with its high prevalence and death toll is one of the most important infectious diseases to study. Yet, there is very little progress in the development of within-host models for HBV, which has subsequently hindered our understanding of this virus. The uncertainty around the proliferation of infected hepatocytes has been studied but never in association with other important biological continuous events such as integrations and superinfections. This is despite the fact that these processes affect the diversity and composition of infected cell population in the liver and an improved understanding of the cellular composition will undoubtedly assist in strategizing against this viral infection. Here, we developed novel mathematical models that incorporate these key biological processes and analyzed them both analytically and numerically. Unaffected by the extent of integrated DNA (IDNA), the outcome of HBV infection was primarily dictated by the balance between processes generating and killing infected hepatocytes containing covalent closed circular DNA (cccDNA). The superinfection was found to be a key process in the spread of HBV infection as its exclusion could not reproduce experimentally observed composition of infected hepatocytes at peak of acute HBV infection, a stage where our model predicts that infected hepatocytes most likely carry both cccDNA and IDNA. Our analysis further suggested the existence of some form of selective advantage of infected hepatocytes containing only IDNA to explain the viral dynamics observed during antiviral treatment and the transition from peak to acute infection. Finally, the fine line between liver destruction and resolution of acute HBV infection was found to be highly influenced by the fate of cccDNA during cellular proliferation.

Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.