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Viruses May 2024HBV infection is challenging to cure due to the persistence of viral covalently closed circular viral DNA (cccDNA). The dedicator of cytokinesis 11 (DOCK11) is... (Review)
Review
HBV infection is challenging to cure due to the persistence of viral covalently closed circular viral DNA (cccDNA). The dedicator of cytokinesis 11 (DOCK11) is recognized as a guanine nucleotide exchange factor (GEF) for CDC42 that has been reported to be required for HBV persistence. DOCK11 is expressed in both the cytoplasm and nucleus of human hepatocytes and is functionally associated with retrograde trafficking proteins Arf-GAP with GTPase domain, ankyrin repeat, and pleckstrin homology domain-containing protein 2 (AGAP2), and ADP-ribosylation factor 1 (ARF1), together with the HBV capsid, in the trans-Golgi network (TGN). This opens an alternative retrograde trafficking route for HBV from early endosomes (EEs) to the TGN and then to the endoplasmic reticulum (ER), thereby avoiding lysosomal degradation. DOCK11 also facilitates the association of cccDNA with H3K4me3 and RNA Pol II for activating cccDNA transcription. In addition, DOCK11 plays a crucial role in the host DNA repair system, being essential for cccDNA synthesis. This function can be inhibited by 10M-D42AN, a novel DOCK11-binding peptide, leading to the suppression of HBV replication both in vitro and in vivo. Treatment with a combination of 10M-D42AN and entecavir may represent a promising therapeutic strategy for patients with chronic hepatitis B (CHB). Consequently, DOCK11 may be seen as a potential candidate molecule in the development of molecularly targeted drugs against CHB.
Topics: Humans; Hepatitis B virus; Guanine Nucleotide Exchange Factors; Hepatocytes; Virus Internalization; Virus Replication; Hepatitis B; DNA, Viral; Animals
PubMed: 38793626
DOI: 10.3390/v16050745 -
Viruses May 2024Hepatitis B virus (HBV) is a major driver of chronic hepatic inflammation, which regularly leads to liver cirrhosis or hepatocellular carcinoma. Immediate innate immune...
Hepatitis B virus (HBV) is a major driver of chronic hepatic inflammation, which regularly leads to liver cirrhosis or hepatocellular carcinoma. Immediate innate immune cell response is crucial for the rapid clearance of the infection. Here, natural killer (NK) cells play a pivotal role in direct cytotoxicity and the secretion of antiviral cytokines as well as regulatory function. The aim of this study was to further elucidate NK cell responses triggered by an HBV infection. Therefore, we optimized HBV in vitro models that reliably stimulate NK cells using hepatocyte-like HepG2 cells expressing the Na-taurocholate co-transporting polypeptide (NTCP) and HepaRG cells. Immune cells were acquired from healthy platelet donors. Initially, HepG2-NTCP cells demonstrated higher viral replication compared to HepaRG cells. Co-cultures with immune cells revealed increased production of interferon-γ and tumor necrosis factor-α by NK cells, which was no longer evident in isolated NK cells. Likewise, the depletion of monocytes and spatial separation from target cells led to the absence of the antiviral cytokine production of NK cells. Eventually, the combined co-culture of isolated NK cells and monocytes led to a sufficient cytokine response of NK cells, which was also apparent when communication between the two immune cell subpopulations was restricted to soluble factors. In summary, our study demonstrates antiviral cytokine production by NK cells in response to HBV HepG2-NTCP cells, which is dependent on monocyte bystander activation.
Topics: Humans; Killer Cells, Natural; Monocytes; Hepatitis B virus; Cytokines; Coculture Techniques; Hep G2 Cells; Hepatitis B; Virus Replication; Interferon-gamma; Tumor Necrosis Factor-alpha; Hepatocytes
PubMed: 38793623
DOI: 10.3390/v16050741 -
Viruses May 2024The outcomes of HBV infections are related to complex immune imbalances; however, the precise mechanisms by which HBV induces immune dysfunction are not well understood.
Galectin-3-ITGB1 Signaling Mediates Interleukin 10 Production of Hepatic Conventional Natural Killer Cells in Hepatitis B Virus Transgenic Mice and Correlates with Hepatocellular Carcinoma Progression in Patients.
BACKGROUND AND AIMS
The outcomes of HBV infections are related to complex immune imbalances; however, the precise mechanisms by which HBV induces immune dysfunction are not well understood.
METHODS
HBV transgenic (HBs-Tg) mice were used to investigate intrahepatic NK cells in two distinct subsets: conventional NK (cNK) and liver-resident NK (LrNK) cells during a chronic HBV infection.
RESULTS
The cNK cells, but not the LrNK cells, were primarily responsible for the increase in the number of bulk NK cells in the livers of ageing HBs-Tg mice. The hepatic cNK cells showed a stronger ability to produce IL-10, coupled with a higher expression of CD69, TIGIT and PD-L1, and lower NKG2D expression in ageing HBs-Tg mice. A lower mitochondrial mass and membrane potential, and less polarized localization were observed in the hepatic cNK cells compared with the splenic cNK cells in the HBs-Tg mice. The enhanced galectin-3 (Gal-3) secreted from HBsAg hepatocytes accounted for the IL-10 production of hepatic cNK cells via ITGB1 signaling. For humans, and expression is positively correlated with expression, and negatively correlated with the poor clinical progression of HCC.
CONCLUSIONS
Gal-3-ITGB1 signaling shapes hepatic cNK cells but not LrNK cells during a chronic HBV infection, which may correlate with HCC progression.
Topics: Animals; Mice, Transgenic; Mice; Killer Cells, Natural; Humans; Hepatitis B virus; Interleukin-10; Carcinoma, Hepatocellular; Liver Neoplasms; Signal Transduction; Liver; Galectin 3; Hepatitis B, Chronic; Disease Progression; Male; Female; Hepatocytes; Mice, Inbred C57BL; Galectins
PubMed: 38793619
DOI: 10.3390/v16050737 -
Viruses May 2024Hepatitis B and C viruses (HBV and HCV) are the leading causes of end-stage liver disease worldwide. Although there is a potent vaccine against HBV, many new infections... (Review)
Review
Hepatitis B and C viruses (HBV and HCV) are the leading causes of end-stage liver disease worldwide. Although there is a potent vaccine against HBV, many new infections are recorded annually, especially in poorly resourced places which have lax vaccination policies. Again, as HBV has no cure and chronic infection is lifelong, vaccines cannot help those already infected. Studies to thoroughly understand the HBV biology and pathogenesis are limited, leaving much yet to be understood about the genomic features and their role in establishing and maintaining infection. The current knowledge of the impact on disease progression and response to treatment, especially in hyperendemic regions, is inadequate. This calls for in-depth studies on viral biology, mainly for the purposes of coming up with better management strategies for infected people and more effective preventative measures for others. This information could also point us in the direction of a cure. Here, we discuss the progress made in understanding the genomic basis of viral activities leading to the complex interplay of the virus and the host, which determines the outcome of HBV infection as well as the impact of coinfections.
Topics: Humans; Hepatitis B virus; Hepatitis B; Coinfection; Genome, Viral; Animals
PubMed: 38793606
DOI: 10.3390/v16050724 -
Viruses Apr 2024Chronic Hepatitis B and D Virus (HBV and HDV) co-infection is responsible for the most severe form of viral Hepatitis, the Hepatitis Delta. Despite an efficient vaccine... (Review)
Review
Chronic Hepatitis B and D Virus (HBV and HDV) co-infection is responsible for the most severe form of viral Hepatitis, the Hepatitis Delta. Despite an efficient vaccine against HBV, the HBV/HDV infection remains a global health burden. Notably, no efficient curative treatment exists against any of these viruses. While physiologically distinct, HBV and HDV life cycles are closely linked. HDV is a deficient virus that relies on HBV to fulfil is viral cycle. As a result, the cellular response to HDV also influences HBV replication. In vitro studying of HBV and HDV infection and co-infection rely on various cell culture models that differ greatly in terms of biological relevance and amenability to classical virology experiments. Here, we review the various cell culture models available to scientists to decipher HBV and HDV virology and host-pathogen interactions. We discuss their relevance and how they may help address the remaining questions, with one objective in mind: the development of new therapeutic approaches allowing viral clearance in patients.
Topics: Humans; Hepatitis Delta Virus; Hepatitis B virus; Hepatitis D; Virus Replication; Animals; Host-Pathogen Interactions; Coinfection; Cell Culture Techniques; Hepatitis B
PubMed: 38793598
DOI: 10.3390/v16050716 -
Viruses Apr 2024The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene...
The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.
Topics: Humans; Hepatitis B Surface Antigens; Female; Male; Middle Aged; Hepatitis B virus; Mutation; Adult; Hepatitis B Antibodies; Hepatitis B, Chronic; Tertiary Care Centers; United States; Immune Evasion; Aged; Prevalence; Young Adult
PubMed: 38793596
DOI: 10.3390/v16050713 -
Viruses Apr 2024This systematic review investigates the immunosuppressive environment in HBV-associated hepatocellular carcinoma (HCC), characterized by dysfunctional and exhausted... (Review)
Review
This systematic review investigates the immunosuppressive environment in HBV-associated hepatocellular carcinoma (HCC), characterized by dysfunctional and exhausted HBV-specific T cells alongside an increased infiltration of HBV-specific CD4+ T cells, particularly regulatory T cells (Tregs). Heightened expression of checkpoint inhibitors, notably PD-1, is linked with disease progression and recurrence, indicating its potential as both a prognostic indicator and a target for immunotherapy. Nevertheless, using PD-1 inhibitors has shown limited effectiveness. In a future perspective, understanding the intricate interplay between innate and adaptive immune responses holds promise for pinpointing predictive biomarkers and crafting novel treatment approaches for HBV-associated HCC.
Topics: Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Hepatitis B virus; Adaptive Immunity; T-Lymphocytes, Regulatory; Programmed Cell Death 1 Receptor; Immune Checkpoint Inhibitors; Hepatitis B; Hepatitis B, Chronic; CD4-Positive T-Lymphocytes; T-Lymphocytes; Immunotherapy
PubMed: 38793588
DOI: 10.3390/v16050707 -
International Journal of Molecular... May 2024Our aim was to develop an accurate, highly sensitive method for HBV genotype determination and detection of genotype mixtures. We examined the preS and 5' end of the HBV...
Our aim was to develop an accurate, highly sensitive method for HBV genotype determination and detection of genotype mixtures. We examined the preS and 5' end of the HBV X gene (5X) regions of the HBV genome using next-generation sequencing (NGS). The 1852 haplotypes obtained were subjected to genotyping via the Distance-Based discrimination method (DB Rule) using two sets of 95 reference sequences of genotypes A-H. In clinical samples from 125 patients, the main genotypes were A, D, F and H in Caucasian, B and C in Asian and A and E in Sub-Saharan patients. Genotype mixtures were identified in 28 (22.40%) cases, and potential intergenotypic recombination was observed in 29 (23.20%) cases. Furthermore, we evaluated sequence conservation among haplotypes classified into genotypes A, C, D, and E by computing the information content. The preS haplotypes exhibited limited shared conserved regions, whereas the 5X haplotypes revealed two groups of conserved regions across the genotypes assessed. In conclusion, we developed an NGS-based HBV genotyping method utilizing the DB Rule for genotype classification. We identified two regions conserved across different genotypes at 5X, offering promising targets for RNA interference-based antiviral therapies.
Topics: Hepatitis B virus; Humans; High-Throughput Nucleotide Sequencing; Genotype; Haplotypes; Hepatitis B; Genotyping Techniques; Conserved Sequence; Coinfection; Genome, Viral; Male; Female; Phylogeny; DNA, Viral; Adult
PubMed: 38791519
DOI: 10.3390/ijms25105481 -
Biochemistry Jun 2024Hepatitis B virus (HBV) displays remarkable self-assembly capabilities that interest the scientific community and biotechnological industries as HBV is leading to an...
Hepatitis B virus (HBV) displays remarkable self-assembly capabilities that interest the scientific community and biotechnological industries as HBV is leading to an annual mortality of up to 1 million people worldwide (especially in Africa and Southeast Asia). When the ionic strength is increased, hepatitis B virus-like particles (VLPs) can assemble from dimers of the first 149 residues of the HBV capsid protein core assembly domain (Cp149). Using solution small-angle X-ray scattering, we investigated the disassembly of the VLPs by titrating guanidine hydrochloride (GuHCl). Measurements were performed with and without 1 M NaCl, added either before or after titrating GuHCl. Fitting the scattering curves to a linear combination of atomic models of Cp149 dimer (the subunit) and = 3 and = 4 icosahedral capsids revealed the mass fraction of the dimer in each structure in all the titration points. Based on the mass fractions, the variation in the dimer-dimer association standard free energy was calculated as a function of added GuHCl, showing a linear relation between the interaction strength and GuHCl concentration. Using the data, we estimated the energy barriers for assembly and disassembly and the critical nucleus size for all of the assembly reactions. Extrapolating the standard free energy to [GuHCl] = 0 showed an evident hysteresis in the assembly process, manifested by differences in the dimer-dimer association standard free energy obtained for the disassembly reactions compared with the equivalent assembly reactions. Similar hysteresis was observed in the energy barriers for assembly and disassembly and the critical nucleus size. The results suggest that above 1.5 M, GuHCl disassembled the capsids by attaching to the protein and adding steric repulsion, thereby weakening the hydrophobic attraction.
Topics: Guanidine; Hepatitis B virus; Capsid; Capsid Proteins; Scattering, Small Angle; Protein Multimerization; Models, Molecular; Virus Assembly; X-Ray Diffraction
PubMed: 38787909
DOI: 10.1021/acs.biochem.4c00077 -
Journal of Virology Jun 2024The antiviral role of the tripartite motif-containing (TRIM) protein family , a member of the E3-ubiquitin ligase family, has recently been actively studied. Hepatitis B...
The antiviral role of the tripartite motif-containing (TRIM) protein family , a member of the E3-ubiquitin ligase family, has recently been actively studied. Hepatitis B virus (HBV) infection is a major contributor to liver diseases; however, the host factors regulated by cytokine-inducible TRIM21 to suppress HBV remain unclear. In this study, we showed the antiviral efficacy of TRIM21 against HBV in hepatoma cell lines, primary human hepatocytes isolated from patient liver tissues, and mouse model. Using TRIM21 knock-out cells, we confirmed that the antiviral effects of interferon-gamma, which suppress HBV replication, are diminished when TRIM21 is deficient. Northern blot analysis confirmed a reduction of HBV RNA levels by TRIM21. Using Luciferase reporter assay, we also discovered that TRIM21 decreases the activity of HBV enhancers, which play a crucial role in covalently closed circular DNA transcription. The participation of the RING domain and PRY-SPRY domain in the anti-HBV effect of TRIM21 was demonstrated through experiments using deletion mutants. We identified a novel interaction between TRIM21 and hepatocyte nuclear factor 4α (HNF4α) through co-immunoprecipitation assay. More specifically, ubiquitination assay revealed that TRIM21 promotes ubiquitin-mediated proteasomal degradation of HNF4α. HNF1α transcription is down-regulated as a result of the degradation of HNF4α, an activator for the HNF1α promoter. Therefore, the reduction of key HBV enhancer activators, HNF4α and HNF1α, by TRIM21 resulted in a decline in HBV transcription, ultimately leading to the inhibition of HBV replication.IMPORTANCEDespite extensive research efforts, a definitive cure for chronic hepatitis B remains elusive, emphasizing the persistent importance of this viral infection as a substantial public health concern. Although the risks associated with hepatitis B virus (HBV) infection are well known, host factors capable of suppressing HBV are largely uncharacterized. This study elucidates that tripartite motif-containing protein 21 (TRIM21) suppresses HBV transcription and consequently inhibits HBV replication by downregulating the hepatocyte nuclear factors, which are host factors associated with the HBV enhancers. Our findings demonstrate a novel anti-HBV mechanism of TRIM21 in interferon-gamma-induced anti-HBV activity. These findings may contribute to new strategies to block HBV.
Topics: Humans; Hepatitis B virus; Animals; Mice; Interferon-gamma; Hepatocytes; Virus Replication; Hepatocyte Nuclear Factor 4; Ribonucleoproteins; Hepatitis B; Hep G2 Cells; Cell Line, Tumor
PubMed: 38780244
DOI: 10.1128/jvi.00468-24