Despite the small size of its genome (3.2 kb) and having only four genes that are encoded within it, the hepatitis B virus (HBV) is one of the most successful viral pathogens in human history. It is estimated that there are about 350-400 million people worldwide who are chronically infected with HBV, and even with the extensive efforts that are being done with preventive vaccination, this malady still remains a clear and present danger to the public health. How is it possible that this small double-stranded DNA virus can escape and outfox the surveillance of the complex human immune system? One explanation is that HBV gene products play multiple roles in infections and throughout the viral life cycle so that the virus can effectively survive under various hostile circumstances. Indeed, the HBV DNA polymerase, for example, exerts several functions such as reverse transcription and RNA degradation, and the HBV X protein not only acts as a transcriptional activator, but it also interferes with the host cells' DNA repair mechanism as well as inducing apoptosis and controlling signal transduction. The HBV surface protein, which is encoded in the env gene, is another intriguing example of such multifunctionality. Thus, our present article overviews and summarizes the multifaceted role of this membrane protein as shown in 1) its role as a structural protein of the virus envelope; 2) its function as the viral ligand for interacting with the viral receptors on host cells; 3) its characteristics as an energy-independent transporter molecule that can mediate the nuclear accumulation of itself and other tagged molecules; 4) its role as a viral transactivator protein that can cause hepatocellular carcinoma; 5) its hypothetical function in viral apoptotic mimicry that results in host anti-inflammatory responses; and last 6) its immunostimulatory property by providing for strong and well-defined B- and T-cell epitopes. Understanding these various functions and the versatility of this single protein will help us decipher and understand the viral- and immuno-pathogenesis of HBV itself.
Animals ; English Abstract ; Hepatitis B Surface Antigens/*physiology ; Humans

<b>OBJECTIVEb>To explore the clinical significance of HBV large protein (HBV-LP) in diagnosing viral replication, we detected the HBV-LP, HBV DNA and the hepatitis B viral markers (HBV M) in the serum of the patients infected with HBV.

<b>METHODSb>HBV-LP and HBV M were analyzed by using ELISA. HBV-DNA was quantitatively detected using real-time fluorescent polymerase chain reaction.

<b>RESULTSb>(1) No significant difference between the detectable rate of HBV DNA and HBV-LP was found in the same HBV M (P 0.05). (2) No significant difference between the positive rate of HBV DNA and HBV-LP was found in HBeAg negative patients. (3) The contents of serum HBV-LP was positively correlated with the number of HBV DNA copies.

<b>CONCLUSIONb>There was a close correlation between the positive rate of HBV-LP and HBV DNA, and HBV-LP is a reliable serological marker that can reflect the replication of HBV.

Adolescent ; Adult ; Aged ; DNA, Viral ; blood ; Female ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; physiology ; Humans ; Male ; Middle Aged ; Virus Replication

<b>OBJECTIVEb>To clarify the relationship between fatal severe form hepatitis occurred during chronic hepatitis B and superinfections of hepatitis A, C, D or E virus as well as hepatitis B e system status and to adopt corresponding measures to reduce the mortality of chronic hepatitis B.

<b>METHODSb>This study detected the superinfections with hepatitis A, C, D or E virus and hepatitis B e system status in 219 patients with fatal severe form hepatitis occurred during chronic hepatitis B by enzyme linked immunosorbent assay.

<b>RESULTSb>The superinfections with hepatitis A, C, D or E virus were found in 1.4% (3/219), 9.6% (21/219), 1.8% (4/219) and 30.1% (66/219) of the patients, respectively, altogether 42.9% (94/219); hepatitis E was prominent and steady in superinfection rate in recent ten years. The causes of 57.1% (125/219) patients were not clear. The positive rate of HBeAg and anti-HBe were 17.0% (16/94) and 54.2% (51/94) in the group of superinfections with hepatitis A, C, D or E virus; and were 27.2% (34/125) and 47.2% (59/125) in the group with unknown causes, respectively.

<b>CONCLUSIONb>These results suggested that the patients with superinfections reached 42.9% (94/219), and the superinfections may be a part of causes of fatal severe form hepatitis, and the mortality of chronic hepatitis B may be decreased by strict food sanitation and use of safe blood products. There were no significant relation between hepatitis B e antigen seroconversion and the fatal severe form hepatitis occurred during chronic hepatitis B.

Adult ; DNA, Viral ; blood ; genetics ; Female ; Hepacivirus ; genetics ; physiology ; Hepatitis A virus ; genetics ; physiology ; Hepatitis B Core Antigens ; blood ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; immunology ; physiology ; Hepatitis B, Chronic ; blood ; mortality ; virology ; Hepatitis Delta Virus ; genetics ; physiology ; Hepatitis E virus ; genetics ; physiology ; Host-Pathogen Interactions ; Humans ; Male ; Middle Aged ; Superinfection ; virology ; Survival Rate

<b>OBJECTIVEb>To investigate the effect of apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G) mediated antiviral activity against hepatitis B virus (HBV) and duck hepatitis B virus (DHBV).

<b>METHODSb>Total RNA was extracted from peripheral blood mononuclear cells (PBMCs), RT-PCR product was cloned into the EcoR I/Hind III restriction sites of the CMV-driven expression vector fused with a hemagglutinin fusion epitope tag at its carboxyl terminal. Replication competent 1.3 fold over-length HBV was constructed with full-length HBV of ayw subtype. The mammalian hepatoma cell HepG2 was cotransfected with the replication competent 1.3 fold over-length HBV and various amounts of CMV-driven expression vector encoding APOBEC3G-HA. Levels of HBsAg and HBeAg in the media of the transfected cells were determined by ELISA, HBV DNA. RNA from intracellular core particles was examined using Northern and Southern blot analyses. Chicken hepatoma cell LMH was cotransfected with head-to-tail dimer of an EcoR I monomer of DHBV and various amounts of CMV-driven expression vector encoding APOBEC3G-HA. DHBV DNA from intracellular core particles was examined using Southern blot analysis.

<b>RESULTSb>CMV-driven expression vector encoding APOBEC3G-HA and replication competent 1.3 fold over-length HBV were constructed. There was a dose dependent decrease in the levels of intracellular core-associated viral (HBV and DHBV) DNA and extracellular production of HBsAg and HBeAg. Levels of intracellular core-associated viral RNA were also decreased, but the expression of HBcAg remained almost unchanged.

<b>CONCLUSIONb>APOBEC3G suppresses HBV and DHBV replication and also suppresses HBsAg and HBeAg expression.

APOBEC-3G Deaminase ; Cytidine Deaminase ; genetics ; Hep G2 Cells ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B Virus, Duck ; physiology ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; physiology ; Humans ; RNA, Messenger ; genetics ; Virus Replication

<b>OBJECTIVEb>To screen and clone the genes of proteins in hepatocytes interacting with hepatitis B virus (HBV) PreS2 by yeast-two hybridization technique.

<b>METHODSb>The HBV PreS2 gene was amplified by polymerase chain reaction (PCR) and HBV PreS2 bait plasmid was constructed by using yeast-two hybridization system 3, then transformed into yeast AH109, followed by mating with yeast Y187 containing liver cDNA library plasmid in 2 YPDA medium. Diploid yeast was plated on synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) and synthetic dropout nutrient medium (SD/-Trp-Leu-Ade-His) containing X-alpha-gal for selecting positive blue clones, then amplified by PCR, sequenced, and performed bioinformatics analysis.

<b>RESULTSb>HBV PreS2 gene was cloned successfully and expressed in yeast AH109.Twenty-six positive colonies were selected, among them, twelve containing metallothionein 2A, one cytochrome C oxidase II, two cytochrome P450 subfamily IV4F, two cytochrome c oxidase subunit 4 isoform 1, three albumin (ALB), one Na(+)K(+) transporting ATPase beta-1 polypeptide, two prealbumin, one lectin galactoside-binding subunit, and Two new genes with unknown function.

<b>CONCLUSIONb>Genes of HBV PreS2 interacting proteins have been successfully cloned, which brings some new clues for studying the biological functions of HBV PreS2 and related proteins.

Cloning, Molecular ; Hepatitis B Surface Antigens ; genetics ; physiology ; Plasmids ; Protein Precursors ; genetics ; physiology ; Two-Hybrid System Techniques ; Yeasts ; genetics

Hepatitis B virus MHBst and HBx fragments were amplified to construct eukaryotic expression vector pCDNA3.1-MHBst and pCDNA3.1-HBx. ST3GalI promoter region was obtained by the method of PCR and GFP report plasmid pEGFP-N1-Psial was constructed. pCDNA3.1-MHBst or pCDNA3.1-HBx with pEGFP-N1-Psial were transiently co-transfected into QGY-7701 cells using calcium phosphate-DNA co-precipitation, respectively. The expressions of Psial-directed GFP were analyzed by FAC-Scalibur. It was found that MHBst/HBx could upregulate ST3GalI promoter activity by 35.2% and 43.8%, respectively. We report the regulation of ST3GalI by MHBst and HBx transactivators. It would be helpful to further investigate the relation between hepatitis B virus infection and sialyltransferase expression.
Gene Expression Regulation, Enzymologic ; Hepatitis B Surface Antigens ; genetics ; physiology ; Hepatitis B virus ; Promoter Regions, Genetic ; Sialyltransferases ; genetics ; Trans-Activators ; genetics ; physiology ; Transfection

<b>OBJECTIVEb>To generate a mouse model of chronic hepatitis B (CHB) infection by performing in vivo transduction of hepatitis B virus (HBV) covalently closed circular (ccc)DNA.

<b>METHODSb>Nude mice were injected with HBV cccDNA at doses of 1.5, 1.0 or 0.5 mug/ml. A control group was generated by giving equal injection volumes of physiological saline. The serum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) on post-injection days 1 and 3, weeks 1-6, 8 and 10 were assayed by reflection immunoassay. At post-injection week 10, all animals were sacrificed and liver tissues were collected. Copies of HBV DNA in serum and liver tissue were detected by real-time PCR. HBV antigens in liver tissue were detected of by immunohistochemistry. Pathological analysis of liver tissue carried out with hematoxylin-eosin staining. Linear correlation of data was determined by statistical analysis.

<b>RESULTSb>HBsAg and HBeAg were detected in sera from all three groups of cccDNA-injected mice staring at post-injection day 1 and lasting through week 10. The levels of HBsAg over the 10-week period showed two patterns of increase-decrease;the lowest level was detected at week 4 and the highest level was detected at week 8. In contrast, the levels of HBeAg over the 10-week period showed three patterns of increase-decrease; the lower levels were detected at weeks 2 and 4 and the higher levels at weeks 3 and 6. HBV DNA copies in liver tissues showed a cccDNA dose-dependent descending trend over the 10-week study period (1.5 mug/ml:1.14E+07 ± 6.51E+06 copies/g, 1.0 mug/ml:9.81E+06 ± 9.32E+06 copies/g, and 0.5 mug/ml:3.72E+06 ± 2.35E+06 copies/g; Pearson's r =0.979). HBV DNA copies in sera showed the pattern of 1.0 mug/ml cccDNA more than 1.5 mug/ml cccDNA more than 0.5 mug/ml cccDNA, and in general were higher than those detected in the liver tissues. Liver tissues from all cccDNA-injected mice showed positive immunohistochemistry staining for both HBsAg and HBeAg. HE staining showed that the liver tissues of all cccDNA-injected mice had severe fatty and vacuolar degeneration and less obvious structure of liver lobules (compared to the liver tissues from control mice).

<b>CONCLUSIONb>The CHB mouse model successfully established in this study by in vivo transduction of HBV cccDNA may represent a useful tool to study the pathogenic mechanisms and potential antiviral treatments of human CHB.

Animals ; DNA, Circular ; administration & dosage ; DNA, Viral ; administration & dosage ; Disease Models, Animal ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; physiology ; Hepatitis B, Chronic ; virology ; Male ; Mice ; Mice, Nude ; Transduction, Genetic ; Virus Replication

<b>OBJECTIVEb>To determine the role of Pre-S1 protein in diagnosing viral replication in patients with chronic hepatitis B.

<b>METHODSb>104 consecutive patients with chronic hepatitis B were included in the study, liver biopsy were performed in all patients. Serial serum samples were studied with the quantitative determination of HBV-DNA by a quantitative PCR assay, determination of Pre-S1 protein by ELISA.

<b>RESULTSb>The positive rates of HBV-DNA and Pre-S1 protein in patients with HBsAg HBeAg anti-HBc (+) both were 96.5%. The positive rates of HBV-DNA and Pre-S1 protein in patients with HBsAg anti-HBe anti-HBc (+) were 81.5%, 72.3%, respectively. The positive rates of HBV-DNA and Pre-S1 protein in patients with HBsAg anti-HBc (+) were 87.5%, 75.0%, respectively. It represented some patients with HBeAg (-) anti-HBe (+/-) still had viral replication. HBV-DNA>10(3) copy/ml as positive criteria for diagnosing viral replication, the positive rate of HBeAg, Pre-S1 were 31.5% (28/89), 80.9% (72/89) in patients with HBV-DNA>10(3) copy/ml, respectively. The concordance rates of HBeAg, Pre-S1 with HBV-DNA were 40.0% (42/104), 82.0% (85/104), respectively.

<b>CONCLUSIONb>It showed that Pre-S1 was more sensitive than HBeAg in diagnosing viral replication in patients with chronic hepatitis B.

Adult ; DNA, Viral ; blood ; Female ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; physiology ; Hepatitis B, Chronic ; virology ; Humans ; Male ; Middle Aged ; Protein Precursors ; blood ; Virus Replication

<b>OBJECTIVEb>To establish a highly expressing and replicating hepatitis B virus (HBV) genome transgenic mouse models for screening anti-HBV drugs and investigating the pathogenesis of hepatitis B.

<b>METHODSb>Elongated HBV genome as the investigated gene was transducted into the pronuclei of the fertilized eggs of mice by the technique of microinjection, then the eggs were transplanted into the oviducts of the pseudopregnant mice. All the newborn mice were screened and identified by PCR and Southern blot detecting genomic DNA in tail tissue, then the positive mice were examined plasma HBsAg, HBeAg by ELISA and plasma HBV DNA by Southern blot.

<b>RESULTSb>Among the 61 offsprings, 18 were positive for tail tissue HBV DNA examination, 7 of which were positive for replication and expression detection.

<b>CONCLUSIONb>Transgenic mice with elongated HBV genome possess high efficiency of replication and expression, which can be used for further investigation.

Animals ; DNA Replication ; DNA, Viral ; genetics ; Disease Models, Animal ; Genome, Viral ; Hepatitis B ; virology ; Hepatitis B Surface Antigens ; genetics ; Hepatitis B e Antigens ; genetics ; Hepatitis B virus ; genetics ; physiology ; Mice ; Mice, Transgenic ; genetics ; Virus Replication

<b>OBJECTIVEb>By studying the possibility of obtaining expression of human hepatitis B virus (HBV) genes and production in normal liver cells from heterologous species like normal primary duck hepatocytes (PDH), to investigate the species-specificity of HBV infection and replication.

<b>METHODSb>Two days after transfecting the complete HBV genome into PDH by electroporation (transfected group), HBsAg and HBeAg in the supernatants and lysates of PDH were measured by the IMX system. Meanwhile, replication of HBV in PDH was analyzed by Southern blotting and dot blotting procedures. PDH was electroporated as control.

<b>RESULTSb>HBsAg in the lysate of transfected group was 9.10 (P/N values, positive?2.1), HBeAg was 1.0 (negative?2.1), both were negative in the supernatants of transfected group. dot blotting revealed that transfected group was strongly positive, whereas the control group was negative. Southern blot analysis of intracellular total DNA indicated that there were relaxed circular (RC), covalently closed circular (CCC) and single-stranded (SS) HBV DNA replicative intermediates in the transfected group, and there was no integrated HBV DNA in the cellular genome. Control groups were negative.

<b>CONCLUSIONSb>Replication of HBV can occur in hepatocytes from nonmammalian species, which strongly supports the idea that replication of HBV has no critical species-specificity, and yet it depends on the endoenvironment of hepatocyte.

Animals ; Cells, Cultured ; DNA Replication ; physiology ; DNA, Viral ; biosynthesis ; Disease Models, Animal ; Ducks ; Electroporation ; Hepatitis B Surface Antigens ; analysis ; Hepatitis B e Antigens ; analysis ; Hepatitis B virus ; genetics ; physiology ; Hepatocytes ; metabolism ; virology ; Humans ; Species Specificity ; Transfection ; Virus Replication