Adenine ; analogs & derivatives ; therapeutic use ; Drug Combinations ; Hepatitis B e Antigens ; blood ; Hepatitis B, Chronic ; drug therapy ; Humans ; Nucleic Acid Synthesis Inhibitors ; therapeutic use ; Nucleosides ; antagonists & inhibitors ; biosynthesis ; Organophosphonates ; therapeutic use ; Thymidine ; analogs & derivatives ; therapeutic use

<b>OBJECTIVEb>To study the role of tumor necrosis factor-alpha (TNFalpha) in the anti-replication effects of tetracycline (Tet) on hepatitis B virus (HBV).

<b>METHODSb>The Tet-dependent regulatory fragment (TO) was PCR amplified from the pcDNA4TM/TO vector, inserted into the pUC118 cloning vector, and verified by sequencing. The counterpart fragment in the pVITRO3 expression vector, which contains two multiple cloning sites (MCSs), was replaced with the confirmed TO to generate a pVITRO3-TO vector. The Tet repressor (TR) gene from the pcDNA6/TR regulatory vector was incorporated into one MCS of pVITRO3-TO and the TNFalpha gene was subsequently incorporated into the other MCS. The resultant vector, pVITRO3-TOTR-TNFalpha, was transiently transfected into HepG2 cells. TNFalpha expression from the vector was induced by exposure to various concentrations of Tet and measured by enzyme-linked immunosorbent assay to determine the appropriate Tet concentration for experimentation. To investigate whether Tet inhibits TNFalpha expression as a mechanism of its anti-replication activity against HBV, the HepG2.2.15 cell line stably transfected with pVITRO3-TOTR-TNFalpha was used as an HBV replication model. Levels of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) were detected by immunoassay. HBV DNA level was detected by fluorescence quantitative PCR.

<b>RESULTSb>The TNFalpha expression from the newly constructed pVITRO3-TOTR-TNFalpha vector was Tet-controllable in the eukaryotic cells examined. The optimal concentration of Tet for the experimental system was 1.0 mug/ml. HBsAg and HBeAg expression was down-regulated in the HepG2.2.15 cells stably transfected with the pVITRO3-TO-TR-TNFalpha vector. After incubation with Tet for 1, 3 and 5 days, the inhibition rate of HBsAg was 2%, 1.1% and 0, compared to 14.8%, 11.5% and 28.4% in the non-Tet control group. The corresponding inhibition rates of HBeAg were 50.0%, 26.7% and 47.9%, compared to 0.3%, 1.6% and 0.0%, in the control group. HBV DNA levels in the cells and the cell culture supernatants exposed to Tet were decreased by 70.3% and 79.9%, respectively. TNFalpha inhibited production of HBsAg mRNA.

<b>CONCLUSIONb>A Tet-dependent regulatory fragment double-expressing TNFalpha single vector system was constructed successfully, achieving controllable TNFalpha expression in both transiently transfected eukaryotic cells and stable cell lines. In this HBV cell model system, Tet-induced overexpression of human TNFalpha inhibited HBV DNA replication and reduced HBsAg and HBeAg expression. Inhibition of HBV transcription may be a key role of TNFalpha against HBV replication.

DNA, Viral ; biosynthesis ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B Surface Antigens ; metabolism ; Hepatitis B e Antigens ; metabolism ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Tetracycline ; pharmacology ; Transfection ; Tumor Necrosis Factor-alpha ; genetics ; Virus Replication

This study sought to investigate the in vivo antiviral effect of amantadine (AM) and biphenyl dimethyl dicarboxylate (DDB) on hepatitis B virus (HBV) in HBV replication mice. HBV replication-competent plasmid was transferred into male BALB/c mice by using hydrodynamics-based in vivo transfection procedure to develop HBV replication mouse model. The model mice were matched by body weigh, age and serum levels of hepatitis B e antigen (HBeAg) and were divided into four groups: AM group, DDB group, AM+DDB group and NS group, with the last one as control, and the mice of each group were administered corresponding agent orally twice a day, in a medication course lasting 3 d. On the third day, the mice were sacrificed 4-6 h after the last oral intake. HBV DNA replication intermediates in liver were analyzed by Southern blot hybridization. The serum hepatitis B surface antigen (HBsAg) and HBeAg were detected by enzyme linked immunosorbent assay (ELISA). Compared to the animals in the control group, HBV DNA replication intermediates in liver and HBsAg and HBeAg in serum from the AM and AM plus DDB group of mice decreased, and there was no difference between these two groups of mice. The levels of HBV DNA intermediate from liver and the serum HBsAg and HBeAg between the control and DDB group, however, were not obviously different. In conclusion, the inhibition effect of AM on HBV was detected, but treatment with DDB for 3 days did not influence the viral replication and expression of HBV in the HBV replication mice.
Amantadine ; pharmacology ; Animals ; Antiviral Agents ; pharmacology ; DNA Replication ; DNA, Viral ; biosynthesis ; Dioxoles ; pharmacology ; Disease Models, Animal ; Hepatitis B ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; drug effects ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; Transfection ; Virus Replication ; drug effects

Betulinic acid is a naturally occurring pentacyclic triterpenoid, which has antiretroviral, antimalarial, and anti-inflammatory properties. The purpose of this study is to investigate the HBV DNA replication inhibition in the mouse model with betulinic acid. Hydrodynamic injection method via the tail vein with the Paywl. 3 plasmid was used to establish the animal mode (n = 15), and the mice were randomly divided into the PBS control group (n = 5), Betulinic acid treatment group (n = 5) and lamivudine control group (n = 5). The day after successful modeling , the mice would have taken Betulinic acid (100 mg x kg(-1)), lamivudine (50 mg x kg(-1)), PBS drugs orally, once daily for 7 days, blood samples were acquired from the orbital venous blood at 3, 5, 7 days after the administering, HBsAg and HBeAg in serum concentration were measured by ELISA and the mice were sacrificed after 7 days, HBV DNA southern detections were used with part of mice livers. The results showed that betulinic acid significantly inhibited the expression of HbsAg in the mice model at the fifth day compared with the control group, and there was no significant differences between the effects of lamivudine and the PBS control group; both the betulinic acid and lamivudine groups had no significant inhibition for the HBeAg expression; the HBV DNA expressions of the liver tissue from the betulinic acid and lamivudine groups were inhibited compared with the control group. Taken together, these results reveal betulinic acid can inhibit the HBsAg expression and replication of the liver HBV DNA in the mouse model.
Acute Disease ; Animals ; Antiviral Agents ; pharmacology ; DNA Replication ; drug effects ; DNA, Viral ; biosynthesis ; Hepatitis B ; blood ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B virus ; drug effects ; genetics ; immunology ; physiology ; Male ; Mice ; Plasmids ; genetics ; Triterpenes ; pharmacology ; Virus Replication ; drug effects

Hepatitis B virus (HBV) DNA replication takes place in the viral capsid that consists of 180 or 240 copies of HBV capsid (HBc or core) protein. The monomeric core protein contains an apical loop region that forms the spikes on the surface of viral capsid upon core dimerization and capsid assembly. To investigate the impact on HBV DNA replication through gene engineering at the spike of HBV capsid. plasmids expressing engineered HBc with linker-fused enhanced green fluorescent protein (EGFP) or shortened EGFP insertion at the spike region were constructed by Restriction Digestion and Ligation-independent Cloning (RLIC). The wildtype or mutant HBc construct was cotransfected with HBV1.1c(-), a plasmid containing 1.1 unit-length HBV genome with deficiency in HBc expression, into HEK293 cells, respectively. GFP signal was observed through a fluorescence microscope and HBV DNA replicative intermediates were assayed by Southern blotting to determine the expression and functions of different recombinants. Our results demonstrated that the RLIC method was effective to generate deletion or insertion in the apical loop region of HBc. Both HBc-EGFP recombinants with different linkers produced green fluorescence but with different subcellular distribution pattern. However, HBV DNA replication was not detected with the trans-complementation of these two HBc recombinants. In addition, other recombinants including the one only with the deletion of aa79-80 failed to support HBV replication. Taken together, our results suggest that RLIC is a robust method which can be broadly applied in gene engineering; different peptide linkers may have different influences on the functions of an engineered fusion protein; and HBc aa79-80 play a critical role for HBc to support HBV DNA replication.
Capsid Proteins ; genetics ; Cloning, Molecular ; Genetic Engineering ; methods ; Green Fluorescent Proteins ; biosynthesis ; genetics ; HEK293 Cells ; Hepatitis B Core Antigens ; biosynthesis ; genetics ; Hepatitis B virus ; genetics ; physiology ; Humans ; Mutation ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transfection ; Virus Replication

Hepatitis B surface antigen (HBsAg) carrying preS sequences could be an ideal candidate for a new hepatitis B virus (HBV) vaccine with higher efficacy. Here we report the success in achieving efficient and stable expression of hepatitis B virus S antigen and preS1 epitope fusion protein (S/preS1) in CHO cells. The HMRCHEF53u/Neo-S/preS1 expression vector carrying S/preS1 gene was constructed and transfected into CHO-S cells. A stable and high-expression CHO cell line, named 10G6, was selected by ELISA and limiting dilution analysis. Western blotting analysis showed S/preS1 expressed from 10G6 cells possessed both S and preS1 antigenicity. 10G6 cells displayed characters of favorable growth and stable S/preS1 expression in repeated batch cultures as evaluated by viable cell density, viability and S/preS1 concentration. And cultivation of 10G6 cells in fed-batch mode resulted in S/preS1 production at 17-20 mg/L with viable cell density at 7 x 10(6)-10 x 10(6) cells/mL.
Animals ; CHO Cells ; Cricetulus ; Epitopes ; biosynthesis ; genetics ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; immunology ; Hepatitis B Vaccines ; biosynthesis ; genetics ; Hepatitis B virus ; Protein Precursors ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transfection

OBJECTIVE: To investigate the effect of extracts with water and alcohol from Radix Trichosanthis on the cell survival and the expression of hepatitis B surface antigen (HBsAg) and hepatitis B e-antigen (HBeAg) in HepG2.2.15 cell supernatant. METHODS: The cell survival rate of HepG2.2.15 cells was detected by MTT assay. The HBsAg and HBeAg in HepG 2.2.15 cell supernatant were evaluated by enzyme linked immunosorbent assay. RESULTS: The water and alcohol soluble extracts from Radix Trichosanthis significantly inhibited the levels of HBsAg and HBeAg in HepG2.2.15 cells in a time-and-concentration-dependent manner. However, the therapeutic index of extracts with water from Radix Trichosanthis was better than that in the alcohol group. CONCLUSION The activity of water-soluble extract from Radix Trichosanthis is stronger on anti-hepatitis B virus than that of the alcohol-soluble extract.
Antiviral Agents ; pharmacology ; Drugs, Chinese Herbal ; classification ; pharmacology ; Hep G2 Cells ; Hepatitis B Surface Antigens ; biosynthesis ; Hepatitis B e Antigens ; biosynthesis ; Hepatitis B virus ; drug effects ; Humans

<b>OBJECTIVEb>To study the effects of immunization with the fusion protein CAC (a product of prokaryotic expression of recombinant HBcAg and β-amyloid peptide fusion gene) against the toxicity induced by intrahippocampal injection of aggregated β-amyloid peptide (Aβ) in rats.

<b>METHODSb>SD rats were immunized intraperitoneally with the fusion protein CAC, and the titer of anti-Aβ antibody was evaluated by ELISA. When the titers of the anti-Aβ antibody reached 1:3 000, aggregated Aβ was injected into the CA1 region of the rat hippocampus. Two weeks after Aβ injection, the rats underwent morris water maze test before sacrificed to prepare the brain slices with Congo red and haematoxylin staining.

<b>RESULTSb>The titer of anti-Aβ antibody reached 1:3 000 after 5 immunizations with the fusion protein. After Aβ injection, the saline-immunized rats showed a reduced cognitive behavior in the Morris water maze test compared to the CAC-immunized rats. In the saline-immunized rats, the neurons around the site of Aβ injection exhibited obvious cell damages with Aβ deposits and glial infiltration, whereas in CAC-immunized rats, Aβ deposits were significantly reduced or even absent.

<b>CONCLUSIONb>Immunization with the fusion protein CAC can inhibit the toxicity induced by intrahippocampal aggregated Aβ injection.

Amyloid beta-Peptides ; administration & dosage ; biosynthesis ; genetics ; immunology ; Animals ; Antibodies ; blood ; Hepatitis B Core Antigens ; biosynthesis ; genetics ; Hippocampus ; metabolism ; Immunization ; Injections ; Male ; Peptide Fragments ; administration & dosage ; immunology ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

<b>OBJECTIVEb>To construct the eukaryotic expression vector of HBEBP1 gene and express HBEBP1 recombinant protein in yeast.

<b>METHODSb>PCR was performed to amplify the gene of HBEBP1 from the cDNA template origining from HepG2, and the gene was cloned into pGEM-T vector. After sequencing, the correct DNA fragment was cut from pGEM-T-HBEBP1 and inserted into yeast expression plasmid pGBKT7. The reconstructed plasmid pGBKT7-HBEBP1 was transformed into yeast cell AH109 and screened on the synthetic dropout nutrient medium (SD/-Trp/Kana). The yeast protein was isolated and analyzed with SDS-PAGE and Western Blot.

<b>RESULTSb>The eukaryotic expressive vector was constructed successfully. The results of Western Blot showed HBEBP1 protein was existed within yeast cells and the molecular weight of it was about 33 x 10(3).

<b>CONCLUSIONSb>The successful expression of HBEBP1 protein in yeast cells lay the foundation for studying biological function of HBEBP1.

Blotting, Western ; Carrier Proteins ; genetics ; Hepatitis B e Antigens ; metabolism ; Plasmids ; Recombinant Proteins ; biosynthesis ; Saccharomyces cerevisiae ; genetics

CD8-Positive T-Lymphocytes ; metabolism ; Case-Control Studies ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B, Chronic ; immunology ; Humans ; Interferon-gamma ; biosynthesis ; Lymphocytes ; immunology ; Oligodeoxyribonucleotides ; pharmacology