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>Screening and characterizing high affinity completely humanized single-chain antibody (ScFv) against PreS1 of hepatitis B virus.

<b>METHODSb>A combinatorial library of phage-displayed human ScFv, genes of which were derived from peripheral blood lymphocytes immunized by PreS1 of Hepatitis B Virus in vitro, was constructed. The library contained 7 10(8) clones.

<b>RESULTSb>After 3 rounds panning, a high affinity (K=10(7) to 10(8) mol/L) ScFv specific to PreS1 was obtained. The V(H) belonged to human V(H4) family, and V(1) to V(4) by sequence analysis.

<b>CONCLUSIONb>This study suggests that the method of antigen stimulation in vitro is an expeditious way for the source of human immune antibody. And the ScFv may provide a more satisfactory therapy.

Antibodies, Monoclonal ; biosynthesis ; Antibody Affinity ; Hepatitis B Antibodies ; biosynthesis ; Hepatitis B Surface Antigens ; immunology ; Humans ; Peptide Library ; Protein Precursors ; immunology

Hepatitis B virus (HBV) infection can cause the severe threat to the health of the people around the world. It depends upon the development of efficient diagnostic reagent and vaccine to prevent the prevalence of HB. In this study, we constructed the high expression recombinant Pichia pastoris and performed the screening tests in shake flasks to obtain the optimal values of several key fermentation parameters. Based on their effects on the growth and expression level of recombinant strains, FBS was the optimal industrial medium. The optimal values for the dissolve oxygen (DO), the final concentrations of methanol and the pH values were 50 mL, 1% (V/V) and 5.4-6.0, respectively. The optimal values of the parameters simulated in shake flasks were successfully scaled up to 10 L bioreactors to achieve high-throughput production: 310 OD600 in biomass and 27 mg/L in recombinant HBsAg. The expressed recombinant HBsAg in P. Pastoris was confirmed by SDS-PAGE and Western blotting. Electron microscopy examination showed that the purified protein could be self-assembled to 22 nm virus-like particles. The results provided a basis for industrial scale-up production of diagnostic reagent and vaccine of next generation against HB.
Bioreactors ; Fermentation ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics

<b>BACKGROUNDb>To establish a new assay for detecting the quantity of HBV DNA with PCR and enzyme-linked immunosorbent assay(ELISA).

<b>METHODSb>The products of PCR using primers pre-labeled with biotin were hybridized with the capture probes that were immobilized on the microtiter strips and then bond with Sav-Ap. The quantity of DNA was detected by measuring the yellow color at 405 nm wave length.

<b>RESULTSb>Totally 125 sera from patients with hepatitis B were tested for HBV DNA by this method,the sera were also tested for HBV immunological markers by solid phase radio immuno-assay (SPRIA). The HBV positive rate with PCR-ELISA was 64.9% (24/37) in samples which were positive for HBsAg, HBeAg and HBcAb; and 34.2% (13/38) in sera which were positive for HBsAg, HBeAb and HBcAb; in sera positive for HBsAg and HBcAb or only HBcAb, the positive rate was 6.7% (1/15) and 5.9% (2/34) respectively.

<b>CONCLUSIONSb>The PCR ELISA assay is simple and suitable for clinical laboratory in quantitative determination of HBV DNA.

DNA Probes ; DNA, Viral ; analysis ; biosynthesis ; genetics ; Enzyme-Linked Immunosorbent Assay ; Hepatitis B ; virology ; Hepatitis B Antibodies ; blood ; Hepatitis B Surface Antigens ; blood ; Hepatitis B e Antigens ; blood ; Hepatitis B virus ; genetics ; isolation & purification ; Humans ; Polymerase Chain Reaction ; Sensitivity and Specificity

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

In order to produce recombinant human anti-HBsAg Fab antibody in Pichia pastoris, the recombinant yeast was fermented using fed-batch system in a 30 L bioreactor. The fermentation temperature was 30 degrees C, the pH was 5.0 approximately 5.3, and the DO was 20% approximately 30%. The recombinant Fab antibody was purified from crude culture supernatant by ion exchange and analyzed by SDS-PAGE and western blot and ELISA. When the absorbance (OD600) of broth reach 300 at the end of fed-batch phase, the induced phase was initiated. The results showed that recombinant human anti-HBsAg Fab antibody was high-level expressed in recombinant Pichia pastoris using a fed-batch fermentation system. Both chains of the Fab were successfully expressed upon methanol induction. After 192 h of induction, the expression level of recombinant Fab (soluble) reached 412 mg/L. The recombinant Fab antibody was purified effectively by ion-exchange chromatography from the fermentation supernatant to a purity of 95%. And the affinity activities of the purified recombinant Fab antibdy and fermentation supernatant were detected, and both of them showed high affinity activities. The results demonstrated that recombinant human anti-HBsAg Fab antibody could be high level produced by fed-batch fermentations in Pichia pastoris. Which can be efficiently used in industrial production.
Fermentation ; Hepatitis B Antibodies ; biosynthesis ; isolation & purification ; Hepatitis B Surface Antigens ; immunology ; Humans ; Immunoglobulin Fab Fragments ; biosynthesis ; isolation & purification ; Pichia ; genetics ; Recombinant Proteins ; biosynthesis ; isolation & purification

<b>OBJECTIVEb>To investigate the presentation of a neutralization epitope-containing peptide antigen of hepatitis E virus (HEV) on chimeric virus-like particles (VLPs) of hepatitis B surface antigen (HBsAg).

<b>METHODSb>The gene fragment corresponding to amino acids (aa) 551-607 (HEnAg) of HEV capsid protein, which contains the only neutralization epitope identified to date, was fused via a synthetic glycine linker in frame with the gene of HBsAg. The resulted fusion gene was then integrated through transformation into the genome of Pichia pastoris under the control of a methanol-induced alcohol oxidase 1 (AOX1) promoter and expressed intracellularly. The expression products in the soluble cell extracts were characterized by Western blot, ELISA, CsCl density gradient analysis, and electron microscopic visualization.

<b>RESULTSb>The novel fusion protein incorporating HBsAg and the neutralization epitope-containing HEnAg was expressed successfully in Pichia pastoris with an expected molecular weight of approximately 32 kD. It was found to possess the ability to assemble into chimeric HBV/HEV VLPs with immunological physical and morphological characteristics akin to HBsAg particles. Not only did the chimeric VLPs show high activity levels in a HBsAg particle-specific ELISA but they were also strongly immunoreactive with hepatitis E (HE) positive human serum in a HEV specific ELISA, indicating that HEnAg peptide fragments were exposed on VLP surfaces and would be expected to be readily accessible by cells and molecules of the immune system. Similarity between chimeric VLPs to highly immunogenic HBsAg particles may confer good immunogenicity on surface-displayed HEnAg.

<b>CONCLUSIONb>The chimeric HBV/HEV VLPs produced in this study may have potential to be a recombinant HBV/HEV bivalent vaccine candidate.

Epitopes ; Genetic Engineering ; Hepatitis Antigens ; biosynthesis ; genetics ; immunology ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; immunology ; Hepatitis B virus ; genetics ; immunology ; Hepatitis E virus ; genetics ; immunology ; Pichia ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; Vaccines, Synthetic

<b>OBJECTIVEb>To explore use of retroviral vector in gene therapy of hepatitis B.

<b>METHODSb>The recombinant vector Plxsn-HBs was constructed by inserting HBV S gene into pLXSN. The pseudovirus, which was produced from PA317 after transferring with pLXSN-HBs by electroporation, were frozen at different temperature. The activities of the pseudovirus to infect eukaryotic cells and express antigen were determined by comparing the numbers of G418-resistant clones and assaying HBsAg in the supernatant of the cells with ELISA after infection HepG2, NIH3T3 and 293 cells.

<b>RESULTSb>It was hard to find changes in HBsAg amount at different intervals and different temperatures. G418 resistant clones, however, were variable. When frozen at -20 degrees C, the numbers of clones were half less than that of the beginning after 6 months, few clones were formed after 12 months, and no clone was found after 24 months. When frozen at -40 degrees C, the numbers of clones were 121, 332 and 89 42, 137 and 43 for HepG2, NIH3T3 and 293 cell lines at 12 and 24 months, respectively. When frozen at -70 degrees C, the numbers of clones were 159 463 and 112 for HepG2, NIH3T3 and 293 cell lines at 24 months, respectively. There was no statistical difference compared to that of zero months.

<b>CONCLUSIONSb>The activity of the peseudovirus to infect eukaryotic cells and expressed antigen was not changed after 2 years frozen at -70 degrees C.

Cell Line ; Genetic Vectors ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Retroviridae ; genetics ; Temperature ; Transfection

<b>OBJECTIVEb>To evoke more effective humoral and cell-mediated immunization against hepatitis B virus (HBV) infection.

<b>METHODSb>HBsAg-primed mice were boosted with HBs-DNA vaccine, and HBs-DNA-primed mice were boosted with HBsAg vaccine. Anti-HBs level was assayed by ELISA and cytotoxic T lymphocyte (CTL) response was tested by lactic acid dehydrogenase (LDH) releasing method two weeks after the boosted immunization.

<b>RESULTSb>Anti-HBs level and CTL responsive rate at the effector/target cell ratio of 100:1 were 0.38 and 36% in HBsAg/HBs-DNA vaccination group, 0.32 and 27% in HBs-DNA/HBsAg vaccination group, 0.48 and 1.5% in HBsAg/HBsAg vaccination group, 0.24 and 68% in HBs-DNA/HBs-DNA vaccination group, respectively.

<b>CONCLUSIONb>Priming with HBs-DNA vaccine followed by boosting with conventional HBsAg vaccine results in greater antibody response (F = 21.19, P < 0.05), and CTL response after HBsAg vaccination can be improved by boosting with HBs-DNA vaccine (F = 165.59, P < 0.05). It brings to better efficacy by combining HBsAg vaccine with HBs-DNA vaccine.

Animals ; Antibody Formation ; Hepatitis B ; immunology ; prevention & control ; Hepatitis B Antibodies ; biosynthesis ; Hepatitis B Surface Antigens ; immunology ; Hepatitis B Vaccines ; administration & dosage ; immunology ; Hepatitis B virus ; genetics ; Immunity, Cellular ; Mice ; Vaccines, DNA ; administration & dosage ; immunology

<b>OBJECTIVEb>To investigate the necessity of detecting on the expressive intensity and pattern of HBsAg and HBcAg in the livers of chronic hepatitis B.

<b>METHODSb>HBsAg and HBcAg were detected in paraffin-embedded liver tissue by EnVision immunohistochemistry. Serum hepatitis B virus DNA (HBV DNA) was tested by real-time quantitative polymerase chain reaction. The degrees of hepatic inflammatory activity (grade) and fibrosis (stage) of liver biopsies were determined according to the standard of the Chinese program of prevention and treatment of viral hepatitis.

<b>RESULTSb>The expression of HBsAg was not correlated with the grade, the stage and the levels of serum HBV DNA (P > 0.05). Liver HBcAg expressive intensity was not correlated with the grade (r=0.02, P > 0.05), while negatively correlated with the stage (r=0.28, P < 0.01) and positively correlated with the serum HBV DNA levels (r=0.53, P < 0.01). Liver HBcAg expressive pattern was negatively correlated with the grade (r=-0.27, P < 0.01). The grade in cytoplasmic pattern group was higher than in nuclear pattern group and in mixed pattern group (P < 0.01), and that in mixed pattern group was higher in nuclear pattern group (P < 0.01). Liver HBcAg expressive pattern was negatively correlated with the stage (r=-0.23, P < 0.01). The stage in cytoplasmic pattern group was higher than in nuclear pattern group and in mixed pattern group (P < 0.05). Liver HBcAg expressive pattern was positively correlated with the levels of serum HBV DNA (r=0.22, P < 0.01).

<b>CONCLUSIONb>Distinguishing the expressive intensity and pattern of HBsAg and HBcAg in the liver of chronic hepatitis B may not help understand the degree of hepatic lesion. The detection of HBcAg in liver tissue of CHB may be beneficial for the antiviral therapy.

Adult ; DNA, Viral ; blood ; genetics ; Female ; Hepatitis B Antigens ; biosynthesis ; Hepatitis B Core Antigens ; biosynthesis ; Hepatitis B Surface Antigens ; biosynthesis ; Hepatitis B virus ; genetics ; immunology ; physiology ; Hepatitis B, Chronic ; pathology ; virology ; Host-Pathogen Interactions ; Humans ; Immunohistochemistry ; Liver ; pathology ; virology ; Male ; Middle Aged ; Reverse Transcriptase Polymerase Chain Reaction ; Virus Replication ; Young Adult