Nucleolin binds to and regulates transcription of hepatitis B virus covalently closed circular DNA minichromosome.

Hepatitis B virus (HBV) remains a major public health threat with nearly 300 million people chronically infected worldwide who are at a high risk of developing hepatocellular carcinoma. Current therapies are effective in suppressing HBV replication but rarely lead to cure. Current therapies do not affect the HBV covalently closed circular DNA (cccDNA), which serves as the template for viral transcription and replication and is highly stable in infected cells to ensure viral persistence. In this study, we aim to identify and elucidate the functional role of cccDNA-associated host factors using affinity purification and protein mass spectrometry in HBV-infected cells. Nucleolin was identified as a key cccDNA-binding protein and shown to play an important role in HBV cccDNA transcription, likely via epigenetic regulation. Targeting nucleolin to silence cccDNA transcription in infected hepatocytes may be a promising therapeutic strategy for a functional cure of HBV.

Leptin receptor somatic mutations are frequent in HCV-infected cirrhotic liver and associated with hepatocellular carcinoma.

BACKGROUND & AIMS: Hepatocellular carcinoma develops in patients with chronic hepatitis or cirrhosis via a stepwise accumulation of various genetic alterations. To explore the genetic basis of development of hepatocellular carcinoma in hepatitis C virus (HCV)-associated chronic liver disease, we evaluated genetic variants that accumulate in nontumor cirrhotic liver. METHODS: We determined the whole exome sequences of 7 tumors and background cirrhotic liver tissues from 4 patients with HCV infection. We then performed additional sequencing of selected exomes of mutated genes, identified by whole exome sequencing, and of representative tumor-related genes on samples from 22 cirrhotic livers with HCV infection. We performed in vitro and in vivo functional studies for one of the mutated genes. RESULTS: Whole exome sequencing showed that somatic mutations accumulated in various genes in HCV-infected cirrhotic liver tissues. Among the identified genes, the leptin receptor gene (LEPR) was one of the most frequently mutated in tumor and nontumor cirrhotic liver tissue. Selected exome sequencing analyses detected LEPR mutations in 12 of 22 (54.5%) nontumorous cirrhotic livers. In vitro, 4 of 7 (57.1%) LEPR mutations found in cirrhotic livers reduced phosphorylation of STAT3 to inactivate LEPR-mediated signaling. Moreover, 40% of Lepr-deficient (C57BL/KsJ-db/db) mice developed liver tumors after administration of thioacetamide compared with none of the control mice. CONCLUSIONS: Based on analysis of liver tissue samples from patients, somatic mutations accumulate in LEPR in cirrhotic liver with chronic HCV infection. These mutations could disrupt LEPR signaling and increase susceptibility to hepatocarcinogenesis.

Accumulation of somatic mutations in TP53 in gastric epithelium with Helicobacter pylori infection.

BACKGROUND & AIMS: Helicobacter pylori infection is a risk factor for gastric cancer. To explore the genetic basis of gastric cancer that develops in inflamed gastric mucosa, we investigated genetic aberrations that latently accumulate in nontumorous gastric epithelium with H pylori infection. METHODS: We performed whole-exome sequencing of gastric tumors, noncancerous tissues with gastritis, and peripheral lymphocytes from 5 patients. We performed additional deep-sequencing analyses of selected tumor-related genes using 34 gastritis mucosal samples from patients with or without gastric cancer. We also performed deep sequencing analyses of gastric mucosal tissues from mice that express transgenic human TP53 and constitutively express activation-induced cytidine deaminase (AICDA or AID) (human TP53 knock-in/AID-transgenic mice). RESULTS: Whole-exome sequencing revealed that somatic mutations accumulated in various genes in inflamed gastric tissues. Additional deep-sequencing analyses of tissues from regions of gastritis confirmed nonsynonymous low-abundance mutations in TP53 in 15 cases (44.1%) and ARID1A in 5 cases (14.7%). The mutations that accumulated in gastric mucosal tissues with H pylori-induced gastritis, as well as gastric tumors, were predominantly C:G>T:A transitions in GpCpX motifs-a marker of cytidine deamination induced by AID. Constitutive expression of AID in the gastric mucosa of mice led to mutations in the human TP53, at amino acid coding positions identical to those detected in human gastric cancers. CONCLUSIONS: Studies of gastric tumors and tissues from humans and mice indicate that somatic mutations accumulate in various genes in gastric mucosal tissues with H pylori infection. Increased cytidine deaminase activity in these tissues appears to promote the accumulation of these mutations and might promote gastric carcinogenesis in patients with H pylori infection.

Reactivation from occult HBV carrier status is characterized by low genetic heterogeneity with the wild-type or G1896A variant prevalence.

BACKGROUND & AIMS: Individuals negative for hepatitis B surface antigen (HBsAg) but positive for antibodies to hepatitis B core antigen (anti-HBc) are at risk of hepatitis B virus (HBV) reactivation under immunosuppressive conditions. We investigated clinical features and viral genetics in patients with reactivation from occult HBV infection triggered by chemotherapy or immunosuppressive therapy. METHODS: Clinical courses of 14 individuals originally HBsAg-negative but anti-HBc-positive that experienced HBV reactivation were examined. Ultra-deep sequencing analysis of the entire HBV genome in serum was conducted. Prevalence of the G1896A variant in latently infected livers was determined among 44 healthy individuals that were HBsAg-negative but anti-HBc-positive. RESULTS: In 14 cases, HBV reactivation occurred during (n=7) and after (n=7) termination of immunosuppressive therapy. Ultra-deep sequencing revealed that the genetic heterogeneity of reactivated HBV was significantly lower in patients with reactivation from occult HBV carrier status compared with that in patients from HBsAg carrier status. The reactivated viruses in each case were almost exclusively the wild-type G1896 or G1896A variant. The G1896A variant was detected in 42.9% (6/14) of cases, including two cases with fatal liver failure. The G1896A variant was observed in the liver tissue of 11.4% (5/44) of individuals with occult HBV infection. CONCLUSIONS: Reactivation from occult HBV infection is characterized by low genetic heterogeneity, with the wild-type G1896 or G1896A variant prevalent.

Effect of nucleoside analog use in patients with hepatitis B virus-related hepatocellular carcinoma.

AIM: To examine the effect of nucleoside analog (NA) therapy on clinical outcome in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) who underwent curative therapy. METHODS: A total of 131 patients with HBV-related HCC who underwent curative therapy were analyzed. They were divided into an NA group who received NA therapy (n = 99, group A) and a control group (n = 32, group B). Group A was further classified into two groups of patients who either received NA therapy before HCC therapy (n = 34, group Aa) or who received NA therapy with initial HCC therapy (n = 65, group Ab). Overall survival (OS) and recurrence-free survival (RFS) were compared in the three groups. RESULTS: The 1- and 3-year cumulative OS rates were both in group Aa, 100% and 88.0% in group Ab, and 100% and 75.7% in group B (overall significance, P = 0.002), respectively. The corresponding RFS rates were 93.1% and 36.0% in group Aa, 78.3% and 45.7% in group Ab, and 78.0% and 38.0% in group B (overall significance, P = 0.734), respectively. Multivariate analysis revealed that being part of group Aa (P < 0.001) or group Ab (P < 0.001) and having albumin levels of 4.0 g/dL or more (P = 0.040) were significantly associated with OS, while HCC stage (P = 0.001) and hepatitis B e-antigen positivity (P < 0.001) were independent predictors linked to RFS. CONCLUSION: NA therapy in patients with HBV-related HCC may improve survival after curative therapy.

Dynamics of defective hepatitis C virus clones in reinfected liver grafts in liver transplant recipients: ultradeep sequencing analysis.

Hepatitis C virus (HCV) reinfects liver allografts in transplant recipients by replicating immediately after transplantation, causing a rapid increase in blood serum HCV RNA levels. We evaluated dynamic changes in the viral genetic complexity after HCV reinfection of the graft liver; we also identified the characteristics of replicating HCV clones using a massively parallel ultradeep sequencing technique to determine the full-genome HCV sequences in the liver and serum specimens of five transplant recipients with genotype 1b HCV infection before and after liver transplantation. The recipients showed extremely high genetic heterogeneity before transplantation, and the HCV population makeup was not significantly different between the liver and blood serum specimens of the individuals. Viral quasispecies complexity in serum was significantly lower after liver transplantation than before it, suggesting that certain HCV clones selectively proliferated after transplantation. Defective HCV clones lacking the structural region of the HCV genome did not increase in number, and full-genome HCV clones selectively increased in number immediately after liver transplantation. A re-increase in the same defective clone existing before transplantation was detected 22 months after transplantation in one patient. Ultradeep sequencing technology revealed that the genetic heterogeneity of HCV was reduced after liver transplantation. Dynamic changes in defective HCV clones after liver transplantation indicate that these clones have important roles in the HCV life cycle.

Impact of peginterferon alpha-2b and entecavir hydrate combination therapy on persistent viral suppression in patients with chronic hepatitis B.

The ideal approach to treat chronic hepatitis B remains controversial. This pilot study aimed to evaluate the effectiveness of peginterferon (PEG-IFN) α-2b and entecavir hydrate (ETV) as a combination therapy for patients with chronic hepatitis B, particularly in the context of virological response and the reduction of intrahepatic covalently closed circular DNA (cccDNA). A total of 17 patients with hepatitis B virus (HBV) genotype C were enrolled in this study. All subjects were treated with this combination therapy for 48 weeks and observed for an additional 24 weeks. All patients underwent liver biopsy before and after the therapy period. Changes in cccDNA levels and liver histology were monitored between biopsies. Among the 11 patients who exhibited pre-therapy hepatitis B e antigen (HBeAg), 8 (73%) showed evidence of HBeAg seroconversion by the end of the follow-up period. Serum HBV DNA levels decreased by 5.2 and 3.3 log copies/ml (mean) by the end of the therapy and follow-up periods, respectively. In addition, intrahepatic cccDNA decreased significantly to 1.4 log copies/µg (mean) by the end of the therapy period. Among the 11 patients who did not experience viral relapse, only 2 (18%) exhibited high levels of cccDNA (>4.5 log copies/µg) by the end of the treatment period. In contrast, all relapsed subjects exhibited significantly higher levels of cccDNA than subjects who did not relapse (P = 0.027). The combination regimen is a promising approach to treat chronic hepatitis B and may achieve significant reduction in serum HBV DNA and intrahepatic cccDNA. Wiley Periodicals, Inc.

The effect of long-term supplementation with branched-chain amino acid granules in patients with hepatitis C virus-related hepatocellular carcinoma after radiofrequency thermal ablation.

GOALS: To elucidate whether long-term supplementation with branched-chain amino acid (BCAA) granules improves overall survival (OS) and recurrence-free survival (RFS) after radiofrequency thermal ablation (RFA) in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC)≤3 cm in diameter with up to 3 nodules and a serum albumin level before RFA of ≤3.5 g/dL. BACKGROUND: Whether BCAA treatment after curative RFA for patients with HCV-related HCC improves OS and RFS remains unclear. STUDY: We compared the OS rate and the RFS rate between the BCAA group (n=115) and the control group (n=141). We also examined factors contributing to OS and RFS. RESULTS: The 1 and 3 years OS rates after RFA were 94.0% and 70.0%, respectively, in the BCAA group, and 94.0% and 49.8%, respectively, in the control group (P=0.001). The corresponding RFS rates 1 and 3 years after RFA were 61.8% and 28.0%, respectively, in the BCAA group, and 52.0% and 12.0%, respectively, in the control group (P=0.013). In the multivariate analysis, in terms of OS, BCAA treatment, and serum albumin level of ≥3.4 g/dL, and in terms of RFS, age 70 years or older, BCAA treatment, and a serum albumin level of ≥3.4 g/dL were significant independent factors, respectively. CONCLUSIONS: BCAA treatment may improve OS and RFS after RFA in patients with HCV-related HCC≤3 cm in diameter with up to 3 nodules and a serum albumin level before RFA of 3.5 g/dL.

Complete response of advanced hepatocellular carcinoma with multiple lung metastases treated with sorafenib: a case report.

Sorafenib, an oral multikinase inhibitor, has demonstrated clinical efficacy in patients with advanced hepatocellular carcinoma (HCC). However, in the SHARP trial (Sorafenib HCC Assessment Randomized Protocol trial) and the Asia-Pacific trial (conducted in the Asia-Pacific region), no cases of complete response (CR) were reported. Thereafter, only a relatively small number of CR cases were reported worldwide for sorafenib therapy. We herein report a case of CR in a patient treated with sorafenib for 4 months. The patient had advanced HCC with multiple lung metastases, and there has been no recurrence after 8 months following cessation of administration. To our knowledge, this is the first time a female treated with sorafenib alone for HCC has had a CR.

Comparison of percutaneous radiofrequency thermal ablation and surgical resection for small hepatocellular carcinoma.

BACKGROUND: The purpose of this investigation was to compare the outcome of percutaneous radiofrequency thermal ablation therapy (PRFA) with surgical resection (SR) in the treatment of single and small hepatocellular carcinoma (HCC). METHODS: We conducted a retrospective cohort study on 231 treatment naive patients with a single HCC ≤ 3 cm who had received either curative PRFA (162 patients) or curative SR (69 patients). All patients were regularly followed up after treatment at our department with blood and radiologic tests. RESULTS: The 1-, 3- and 5-year overall survival rates after PRFA and SR were 95.4%, 79.6% and 63.1%, respectively in the PRFA group and 100%, 81.4% and 74.6%, respectively in the SR group. The corresponding recurrence free survival rates at 1, 3 and 5 years after PRFA and SR were 82.0%, 38.3% and 18.0%, respectively in the PRFA group and 86.0%, 47.2% and 26.0%, respectively in the SR group. In terms of overall survival and recurrence free survival, there were no significant differences between these two groups. In comparison of PRFA group patients with liver cirrhosis (LC) (n = 127) and SR group patients with LC (n = 50) and in comparison of PRFA group patients without LC (n = 35) and SR group patients without LC (n = 19), there were also no significant differences between two groups in terms of overall survival and recurrence free survival. In the multivariate analysis of the risk factors contributing to overall survival, serum albumin level was the sole significant factor. In the multivariate analysis of the risk factors contributing to recurrence free survival, presence of LC was the sole significant factor. The rate of serious adverse events in the SR group was significantly higher than that in the PRFA group (P = 0.023). Hospitalization length in the SR group was significantly longer than in the PRFA group (P = 0.013). CONCLUSIONS: PRFA is as effective as SR in the treatment of single and small HCC, and is less invasive than SR. Therefore, PRFA could be a first choice for the treatment of single and small HCC.

Genetically edited hepatic cells expressing the NTCP-S267F variant are resistant to hepatitis B virus infection.

The sodium-dependent taurocholate co-transporting polypeptide (NTCP)-S267F variant is known to be associated with a reduced risk of hepatitis B virus (HBV) infection and disease progression. The NTCP-S267F variant displays diminished function in mediating HBV entry, but its function in HBV infection has not been fully established in more biologically relevant models. We introduced the NTCP-S267F variant and tested infectivity by HBV in genetically edited hepatic cells. HepG2-NTCP clones with both homozygous and heterozygous variants were identified after CRISPR base editing. NTCP-S267F homozygous clones did not support HBV infection. The heterozygote clones behaved similarly to wild-type clones. We generated genetically edited human stem cells with the NTCP-S267F variant, which differentiated equally well as wild-type into hepatocyte-like cells (HLCs) expressing high levels of hepatocyte differentiation markers. We confirmed that HLCs with homozygous variant did not support HBV infection, and heterozygous variant clones were infected with HBV equally as well as the wild-type cells. In conclusion, we successfully introduced the S267F variant by CRISPR base editing into the NTCP/SLC10A gene of hepatocytes, and showed that the variant is a loss-of-function mutation. This technology of studying genetic variants and their pathogenesis in a natural context is potentially valuable for therapeutic intervention against HBV.

Advances in Oncology in US and Japan: Focusing on Cancer and Infectious Diseases.

This is a review article based on the international symposium report of the "US-Japan Conference on Advances in Oncology: Cancer and Infectious Diseases" held online on June 25, 2021, which provided an update on the association between oncology and infectious disease research from cutting-edge basic science to high-impact clinical trials.

Expansion of viral variants associated with immune escape and impaired virion secretion in patients with HBV reactivation after resolved infection.

HBV reactivation could be induced under immunosuppressive conditions in patients with resolved infection. This study aimed to clarify the viral factors associated with the pathogenesis of HBV reactivation in association with the immunosuppressive status. Whole HBV genome sequences were determined from the sera of 24 patients with HBV reactivation, including 8 cases under strong immunosuppression mediated by hematopoietic stem cell transplantation (HSCT) and 16 cases without HSCT. Ultra-deep sequencing revealed that the prevalence of genotype B and the ratio of non-synonymous to synonymous evolutionary changes in the surface (S) gene were significantly higher in non-HSCT cases than in patients with HSCT. Those non-synonymous variants included immune escape (6/16 cases) and MHC class II-restricted T-cell epitope variants (6/16 cases). Furthermore, reactivated HBV in 11 of 16 (69%) non-HSCT cases possessed substitutions associated with impaired virion secretion, including E2G, L77R, L98V, T118K, and Q129H in the S region, and M1I/V in the PreS2 region. In conclusion, virologic features of reactivated HBV clones differed depending on the intensity of the immunosuppressive condition. HBV reactivation triggered by immunosuppressive conditions, especially those without HSCT, was characterized by the expansion of variants associated with immune escape, MHC class II-restricted T-cell epitope alterations, and/or impaired virion secretion.

Genetic basis of hepatitis virus-associated hepatocellular carcinoma: linkage between infection, inflammation, and tumorigenesis.

Hepatitis virus infection is a leading cause of chronic liver disease, including cirrhosis and hepatocellular carcinoma (HCC). Although anti-viral therapies against hepatitis B virus (HBV) and hepatitis C virus (HCV) have dramatically progressed during the past decade, the estimated number of people chronically infected with HBV and/or HCV is ~370 million, and hepatitis virus-associated hepatocarcinogenesis is a serious health concern worldwide. Understanding the mechanism of virus-associated carcinogenesis is crucial toward both treatment and prevention, and the recently developed whole genome/exome sequencing analysis using next-generation sequencing technologies has contributed to unveiling the landscape of genetic and epigenetic aberrations in not only tumor tissues but also the background liver tissues underlying chronic liver damage caused by hepatitis virus infection. Several major mechanisms underlie the genetic and epigenetic aberrations in the hepatitis virus-infected liver, such as the generation of reactive oxidative stress, ectopic expression of DNA mutator enzymes, and dysfunction of the DNA repair system. In addition, direct oncogenic effects of hepatitis virus, represented by the integration of HBV-DNA, are observed in infected hepatocytes. Elucidating the whole picture of genetic and epigenetic alterations, as well as the mechanisms of tumorigenesis, will facilitate the development of efficient treatment and prevention strategies for hepatitis virus-associated HCC.

Activation of TNF-α-AID axis and co-inhibitory signals in coordination with Th1-type immunity in a mouse model recapitulating hepatitis B.

Hepatitis B virus (HBV) infection evokes host immune responses that primarily determine the outcome of HBV infection and the clinical features of HBV-associated liver disease. The precise mechanisms by which host factors restrict HBV replication, however, are poorly understood due to the lack of useful animal models that recapitulate immune responses to HBV. Here, we performed comprehensive immunologic gene expression profiling of the liver of a mouse model recapitulating anti-HBV immune response using a high sensitivity direct digital counting system. Anti-HBV cellular immunity with liver inflammation was elicited in mice hydrodynamically injected with a CpG-depleted plasmid encoding hepatitis B surface antigen (HBsAg) gene after preimmunization with HBsAg vaccine. Comprehensive expression analyses revealed the upregulation of Th1-associated genes including tumor necrosis factor (Tnf) and negative regulators of T cell function in the inflamed liver. Interestingly, activation-induced cytidine deaminase (Aicda, termed AID in humans), which reportedly suppresses HBV infection in vitro, was upregulated in hepatocytes in the course of anti-HBV immunity. Hepatocytic expression of Aicda in a Tnf-dependent manner was confirmed by the administration of Tnf antagonist into Aicda-tdTomato mice with anti-HBV immunity. Our findings suggest that activation of Tnf-Aicda axis and co-inhibitory signals to T cells in coordination with Th1-type immunity has critical roles in the immune response against HBV infection.

Evolution of multi-drug resistant HCV clones from pre-existing resistant-associated variants during direct-acting antiviral therapy determined by third-generation sequencing.

Resistance-associated variant (RAV) is one of the most significant clinical challenges in treating HCV-infected patients with direct-acting antivirals (DAAs). We investigated the viral dynamics in patients receiving DAAs using third-generation sequencing technology. Among 283 patients with genotype-1b HCV receiving daclatasvir + asunaprevir (DCV/ASV), 32 (11.3%) failed to achieve sustained virological response (SVR). Conventional ultra-deep sequencing of HCV genome was performed in 104 patients (32 non-SVR, 72 SVR), and detected representative RAVs in all non-SVR patients at baseline, including Y93H in 28 (87.5%). Long contiguous sequences spanning NS3 to NS5A regions of each viral clone in 12 sera from 6 representative non-SVR patients were determined by third-generation sequencing, and showed the concurrent presence of several synonymous mutations linked to resistance-associated substitutions in a subpopulation of pre-existing RAVs and dominant isolates at treatment failure. Phylogenetic analyses revealed close genetic distances between pre-existing RAVs and dominant RAVs at treatment failure. In addition, multiple drug-resistant mutations developed on pre-existing RAVs after DCV/ASV in all non-SVR cases. In conclusion, multi-drug resistant viral clones at treatment failure certainly originated from a subpopulation of pre-existing RAVs in HCV-infected patients. Those RAVs were selected for and became dominant with the acquisition of multiple resistance-associated substitutions under DAA treatment pressure.

Sonazoid-enhanced ultrasonography guidance improves the quality of pathological diagnosis in the biopsy of focal hepatic lesions.

BACKGROUND/AIM: Contrast-enhanced ultrasonography (US) has improved the detection and characterization of focal hepatic lesions. Recently, the importance of obtaining high-quality samples in the biopsy of hepatic lesions has been increasing not only in the field of pathological diagnosis but also in molecular analysis for predicting the effectiveness of anticancer agents and molecular targeted drugs. We evaluated the utility of Sonazoid-enhanced ultrasonography (SEUS) in guiding percutaneous biopsy of focal hepatic lesions by comparing the results of histopathological diagnosis between B-mode US and SEUS guidance. METHODS AND MATERIALS: This retrospective study examined 121 focal hepatic lesions in 108 patients (mean age: 63.8 years) referred for US-guided percutaneous biopsy. The technical success rate was defined as the percentage of the lesions diagnosed clearly at the initial biopsy. RESULTS: Among 121 lesions, 56 lesions were subjected to biopsy with B-mode US guidance whereas 65 were subjected to SEUS guidance. The technical success rate was significantly higher under SEUS guidance than under B-mode US guidance (92.3 vs. 76.8%, respectively, P<0.05). When biopsies were performed to diagnose or rule out malignancy in indeterminate lesions, the technical success rate was also significantly higher under SEUS guidance than under B-mode US guidance (100 vs. 73.9%, respectively, P<0.05). SEUS guidance resulted in a significantly higher rate of successful single-puncture attempts compared with B-mode US guidance (55.4 vs. 35.7%, respectively, P<0.05). CONCLUSION: SEUS guidance is recommended for more accurate localization of suitable hepatic lesion biopsy areas as it increases conspicuity and differentiates viable areas from denaturalization or necrosis.

MSH2 Dysregulation Is Triggered by Proinflammatory Cytokine Stimulation and Is Associated with Liver Cancer Development.

Inflammation predisposes to tumorigenesis in various organs by potentiating a susceptibility to genetic aberrations. The mechanism underlying the enhanced genetic instability through chronic inflammation, however, is not clear. Here, we demonstrated that TNFα stimulation induced transcriptional downregulation of MSH2, a member of the mismatch repair family, via NF-κB-dependent miR-21 expression in hepatocytes. Liver cancers developed in ALB-MSH2(-) (/) (-)AID(+), ALB-MSH2(-) (/) (-), and ALB-AID(+) mice, in which MSH2 is deficient and/or activation-induced cytidine deaminase (AICDA) is expressed in cells with albumin-producing hepatocytes. The mutation signatures in the tumors developed in these models, especially ALB-MSH2(-) (/) (-)AID(+) mice, closely resembled those of human hepatocellular carcinoma. Our findings demonstrated that inflammation-mediated dysregulation of MSH2 may be a mechanism of genetic alterations during hepatocarcinogenesis. Cancer Res; 76(15); 4383-93. ©2016 AACR.

Mouse models of hepatitis B virus infection comprising host-virus immunologic interactions.

Hepatitis B virus (HBV) infection is one of the most prevalent infectious diseases associated with various human liver diseases, including acute, fulminant and chronic hepatitis; liver cirrhosis; and hepatocellular carcinoma. Despite the availability of an HBV vaccine and the development of antiviral therapies, there are still more than 350 million chronically infected people worldwide, approximately 5% of the world population. To understand the virus biology and pathogenesis in HBV-infected patients, several animal models have been developed to mimic hepatic HBV infection and the immune response against HBV, but the narrow host range of HBV infection and lack of a full immune response spectrum in animal models remain significant limitations. Accumulating evidence obtained from studies using a variety of mouse models that recapitulate hepatic HBV infection provides several clues for understanding host-virus immunologic interactions during HBV infection, whereas the determinants of the immune response required for HBV clearance are poorly defined. Therefore, adequate mouse models are urgently needed to elucidate the mechanism of HBV elimination and identify novel targets for antiviral therapies.