Bad Liver and a Broken Heart: Hepatitis B in the Newborn.

Hepatitis B viral infection is a significant source of morbidity and mortality worldwide. The United States has experienced a precipitous drop in acute hepatitis B infection after the introduction and widespread adoption of recombinant vaccines. Neonates experience significant risk from both vertical and horizontal hepatitis B exposure during a period of immaturity of the innate and adaptive immune systems. Acquisition of hepatitis B virus at or near birth confers the highest lifetime risk of chronic infection and subsequent complications including liver cirrhosis and hepatocellular carcinoma. Pregnant women should be screened for the presence of hepatitis B surface antigen, indicating acute or chronic infection, and, if positive, hepatitis B viral deoxyribonucleic acid, allowing for quantification of viral load. The development of highly effective and safe recombinant vaccines allows partial protection of late preterm and term neonates immediately after birth. Additionally, administration of hepatitis B immune globulin in the setting of suspected or confirmed exposure supplements the immune response and decreases the risk of chronic infection. The optimal timing of vaccination is later in low-birth-weight neonates due to the aforementioned immune system immaturity. Health care providers serving neonates must familiarize themselves with national guidelines regarding hepatitis B vaccination and hepatitis B immune globulin therapy. Understanding the risks of infection and the evidence basis supporting vaccination and immunotherapy will allow providers to educate families and support decision-making, with the potential to eradicate this vaccine-preventable illness in our lifetime.

LncRNA XIST upregulates TRIM25 via negatively regulating miR-192 in hepatitis B virus-related hepatocellular carcinoma.

BACKGROUND: Long non-coding RNA (lncRNA) XIST has been implicated in the progression of a variety of tumor diseases. The purpose of this study was to explore the molecular role of lncRNA XIST in human hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). METHODS: The expression levels of lncRNA XIST, miR-192 and TRIM25 in HBV-related HCC tissues and HepG2.2.15 cells were detected by qRT-PCR. Biological information and luciferin gene reporter assay were performed to detect the interaction among lncRNA XIST, miR-192 and TRIM25. CCk-8 assay, wound healing assay and colony formation assay were conducted to detect the proliferation and migration ability of HepG2.2.15 cells. RESULTS: qRT-PCR results showed that the expression levels of lncRNA XIST were remarkably increased in HBV-related HCC tissues and HepG2.2.15 cells. In addition, miR-192 was a direct target gene of lncRNA XIST, and the expression of miR-192 and lncRNA XIST were negatively correlated. Moreover, overexpression of miR-192 observably inhibited the proliferation and migration of HCC cells, while overexpression of lncRNA XIST showed an opposite effect. Furthermore, TRIM25 was a direct target of miR-192, and lncRNA XIST could up-regulate the expression of TRIM25 by targeting miR-192. CONCLUSION: LncRNA XIST could up-regulate the expression of TRIM25 by targeting and binding to miR-192, thus accelerating the occurrence and development of HCC.

Hepatitis B immunoglobulin inhibits the secretion of HBV via antigen-antibody precipitation in the multivesicular body.

BACKGROUND AND AIMS: Although the main action of human hepatitis B immunoglobulin (HBIG) is to neutralize hepatitis B virus surface antigen (HBsAg) in serum, HBIG is known to be localized in the cell. However, the effect of intracellularly located HBIG is poorly understood because of the low purity of conventional plasma-derived HBIG (cHBIG). We attempted to elucidate the mechanism of action of internalized HBIG using recombinant HBIG (lenvervimab). METHODS: We used HBsAg producing cell lines, non-HBsAg cell lines and human HBsAg-producing hepatocytes. The autophagosome lysis pathway-related proteins Rab5, calnexin, giantin, and Rab7 were used to localize HBsAg and anti-HBs-IgG in the cytoplasm using Western blotting and confocal microscopy. RESULTS: Intracellular anti-HBs-IgG (lenvervimab and cHBIG) transported via Fc receptor-mediated endocytosis increased the number of autophagosomes. However, there was no change in autolysis. HBsAg and anti-HBs-IgG co-localized in the multivesicular body and precipitated in the cytoplasm. HBsAg secretion into culture medium decreased after lenvervimab treatment. Simultaneously, the amount of cellular HBsAg increased in the cell lines but decreased in human hepatocytes. Furthermore, intracellular lenvervimab is not easily removed from HBsAg cell lines. CONCLUSIONS: Lenvervimab decreases HBsAg secretion, and HBsAg antibody precipitation in the multivesicular body may play an important role.

In silico Analysis of Genetic Diversity of Human Hepatitis B Virus in Southeast Asia, Australia and New Zealand.

The extent of whole genome diversity amongst hepatitis B virus (HBV) genotypes is not well described. This study aimed to update the current distribution of HBV types and to investigate mutation rates and nucleotide diversity between genotypes in Southeast Asia, Australia and New Zealand. We retrieved 930 human HBV complete genomes from these regions from the NCBI nucleotide database for genotyping, detection of potential recombination, serotype prediction, mutation identification and comparative genome analyses. Overall, HBV genotypes B (44.1%) and C (46.2%) together with predicted serotypes adr (36%), adw2 (29%) and ayw1 (19.9%) were the most commonly circulating HBV types in the studied region. The three HBV variants identified most frequently were p.V5L, c.1896G>A and double mutation c.1762A>T/c.1764G>A, while genotypes B and C had the widest range of mutation types. The study also highlighted the distinct nucleotide diversity of HBV genotypes for whole genome and along the genome length. Therefore, this study provided a robust update to HBV currently circulating in Southeast Asia, Australia and New Zealand as well as an insight into the association of HBV genetic hypervariability and prevalence of well reported mutations.

Human Hepatitis B Virus Core Protein Inhibits IFNα-Induced IFITM1 Expression by Interacting with BAF200.

Human hepatitis B virus core protein (HBc) is a structural protein of the hepatitis B virus (HBV) and contributes to HBV regulation of host-cell transcription. However, the mechanisms of transcriptional regulation remain poorly characterized. To dissect the function of HBc, a yeast two-hybrid was performed to identify HBc-binding proteins, and the C-terminal of BRG1/hBRM-associated factors 200 (BAF200C) was identified. Then, the existence of HBc interactions with BAF200C and full-length BAF200 was confirmed via co-immunoprecipitation assays in 293T, HepG2 and HepG2-NTCP cells. Furthermore, we show that the binding between HBc and BAF200 was of vital importance to HBc mediated downregulation of interferon-induced transmembrane protein 1 (IFITM1) expression, and the mechanisms for the downregulation were disclosed as follows. Basal level of IFITM1 expression depends on BAF200, rather than the JAK-STAT1 pathway. The interaction of HBc with BAF200 disturbs the stability of the polybromo-associated BAF (PBAF) complex and results in the suppression of IFTM1 transcription. Finally, the antiviral effects of IFITM1 on cell proliferation and HBV replication were found to be partially restored when HBc was co-transfected with BAF200. Collectively, our findings indicate that HBc plays a role in HBV resistance against the antiviral activities of IFNα, providing details about HBV evasion of host innate immunity.

Differential effects of anti-cancer and anti-hepatitis drugs on liver cystatin.

The drug-protein interaction has been the subject of increasing interest over the decades. In the present communication, the interaction of liver cystatin with anti-cancer (adriamycin) and anti-hepatitis (adevofir dipivoxil) drugs was studied by thiol-protease inhibitory assay, UV absorption, fluorescence spectroscopy and circular dichroism (CD). A static type of quenching was observed between the protein and the drug molecules. Binding constant (Ka) of adriamycin to liver cystatin (LC) was found to be 1.08 × 10(6) M(-1). Moreover, binding site number was found to be 2. Importantly, cystatin loses its activity in the presence of adriamycin. However, intrinsic fluorescence studies in the presence of adevofir dipivoxil showed enhancement in the fluorescence intensity suggesting that binding of adevofir to LC caused unfolding of the protein. The unfolding of the test protein was also accompanied by significant loss of inhibitory activity. CD spectroscopy result showed, both adriamycin and adevofir dipivoxil caused perturbation in the secondary structure of liver cystatin. The possible implications of these results will help in combating drug induced off target effects.

Liver cell-specific peptides derived from the preS1 domain of human hepatitis B virus.

The envelope of human hepatitis B virus (HBV) consists of the large (L), middle (M), and small (S) surface proteins. The preS1 domain at the N terminus of the L-protein is essential for recognizing a target cell and for viral infectivity. In the present study, peptides derived from the preS1 domain (amino acid residues 2-19) were synthesized, and their binding affinities for human hepatocellular carcinoma (HCC) cells were determined. Non-myristoylated peptides showed much lower affinity for HepG2 cells than myristoylated peptides. Although all peptides showed significantly higher affinities for two human HCC cell lines (HepG2 and HuH-7) compared with other cell lines (HeLa, B16, NMuLi, and NIH 3T3), a modified peptide exhibited the highest affinity for HCC cell lines. These results suggest that the modified peptide can target liver cells.