Antiviral Agents ; pharmacology ; Dideoxyadenosine ; analogs & derivatives ; pharmacology ; Hepatitis B virus ; drug effects ; Virus Replication ; drug effects

This study was to establish a model to explore anti- RSV effect of different administration method of Chinese medicine realgar on respiratory syncytial virus type A (RSV-A) replication in Hep-2 cells. Using high-energy ball milling with distilled water to prepare realgar nanoparticles,the concentration of nanometer realgar was tested by molybdenum blue staining method and the size of realgar nanoparticles was tested on Nano Series. Cell culture with ribavirin as a positive control was applied to observe the effect of anti-respiratory syncytial virus type A replication through prevention, treatment or direct inactivation of three different drug administration methods. Realgar nano-particles was found to be a potential inhibitor of RSV-A in a concentration-dependent manner with the median toxic concentration(TC50) of 0.649 microg/mL in Hep-2 cell culture. The median inhibition concentration (IC50) was 0.20 microg/mL when drug was added before virus infection. The IC50 was 0.13 microg/mL when drug was added after virus infection,and it was 0.16 microg/mL when the drug was mixed with virus and added. The therapeutic index (TI) was 3.18, 4.99 and 4.11, respectively. The results showed realgar nanoparticles could inhibit the replication of the RSV and inactivate the RSV in vitro.
Arsenicals ; pharmacology ; Nanoparticles ; Respiratory Syncytial Viruses ; drug effects ; physiology ; Sulfides ; pharmacology ; Virus Replication ; drug effects

OBJECTIVETo observe the inhibitory effect of a eukaryotic expression vector expressing human IFN-gamma (pcDNA3.1- IFN-gamma) on HBV replication in hepG2.2.15 cells.

METHODSThe eukaryotic expression vector expressing human IFN-gamma was constructed using PCR and gene recombination technique. hepG2.2.15 cells were transfected with pcDNA3.1-IFN-gamma and the culture supernatant was collected to determine the expression of IFN-gamma protein by ELISA. The HBV DNA copies and the concentration of HBeAg and HBsAg were measured by fluorescence real-time PCR and ELISA kit, respectively.

RESULTSCompared with that of negative control and blank 2.2.15 cells, the concentration of HBeAg in the supernatant of 2.2.15 cells transfected with pcDNA3.1- IFN-gamma were decreased by 49%, and HBsAg concentration was lowered by 35% and 33%, respectively. A significant decrease of HBV DNA copies was observed in pcDNA3.1- IFN-gamma-transfected cells in comparison with the two control cells. No significant differences were noted in all the results between the two control groups.

CONCLUSIONWe have successfully constructed the eukaryotic expression vector expressing human IFN-gamma, which provides a basis for anti-HBV gene therapy using human IFN-gamma.

Genetic Vectors ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; Humans ; Interferon-gamma ; genetics ; pharmacology ; Transfection ; Virus Replication ; drug effects

OBJECTIVETo evaluate the effectiveness of small interfering RNA (siRNA) on inhibiting severe acute respiratory syndrome (SARS)-associated coronavirus replication, and to lay bases for the future clinical application of siRNA for the treatment of viral infectious diseases.

METHODSVero-E6 cells was transfected with siRNA before SARS virus infection, and the effectiveness of siRNA interference was evaluated by observing the cytopathic effect (CPE) on Vero-E6 cells.

RESULTSFive pairs of siRNA showed ability to reduce CPE dose dependently, and two of them had the best effect.

CONCLUSIONsiRNA may be effective in inhibiting SARS-associated coronavirus replication.

Animals ; Cercopithecus aethiops ; RNA, Small Interfering ; pharmacology ; SARS Virus ; drug effects ; Transfection ; Vero Cells ; Virus Replication ; drug effects

Chinese scorpion Buthus martensii Karsch (BmK) venom is a rich source of neurotoxins which bind to various ion channels with high affinity and specificity and thus widely used as compounds to modulate channel gating or channel currents. To promote the insecticidal effects of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV), the gene encoding an excitatory insect toxin, BmK IT, was inserted into the genome of AcMNPV to construct a recombinant baculovirus, AcMNPV-BmK IT. Spodopter frugiperda 9 (Sf9) cells were infected with AcMNPV and AcMNPV-BmK IT respectively for 24 h. Results from the MTT assay, TUNEL assay, analysis of the expression level of apoptosis-related proteins (c-Myc, cleaved-Caspase3, Bcl-2 and Bax) of Sf9 cells, the transcription level of key genes (38K, C42, P78, F) of AcMNPV, and viral propagation assay demonstrated that AcMNPV-mediated expression of BmK IT promoted the apoptosis of Sf9 cells and replication of AcMNPV. The results laid a foundation for further structural and functional analysis of BmK IT.
Animals ; Apoptosis ; Cell Line ; Nucleopolyhedrovirus ; metabolism ; physiology ; Scorpion Venoms ; biosynthesis ; Sf9 Cells ; drug effects ; Virus Replication

This study is to establish a cell-based pharmacological model targeting HIV-1 replication for compounds screening and to screen compounds randomly selected from compounds library by using this pseudotyped viral system. The cell-based HIV-1 replication pharmacological model was set up by HIV-1 core packed with vesicular stomatitis virus glycoprotein. The level of HIV-1 replication was presented by reporter genes expression (luciferase activity or percentage of GFP positive cells). When a compound has inhibitory effect on VSVG/HIV model, VSVG/MLV model would be used to test for specificity. Vesicular stomatitis virus glycoprotein can efficiently mediate HIV core into a wide range of host cells. Expression level of reporter genes showed dose-dependent manner with virion dilution. Among 500 compounds, three compounds dose-dependently inhibit HIV-1 replication, but not MLV replication. VSVG/HIV pseudotyped viral system can be used as a pharmacological model for HIV-1 replication inhibitor screening. Compounds 2-methylthio-5-(4-methylbenzo)amido-l,3,4-thiadiazole, N-(3-hydroxyphenyl)-2-(4-isobutylphenyl) propionamide, and N-(4-picolyl)-4-methylbenzenesulfonamide can specifically inhibit HIV-1 replication with IC50 of 1.92, 5.38, and 3.39 micromol L(-1) respectively.
Anti-HIV Agents ; pharmacology ; DNA Replication ; drug effects ; Didanosine ; pharmacology ; Drug Evaluation, Preclinical ; methods ; Genes, Reporter ; drug effects ; genetics ; HIV-1 ; drug effects ; physiology ; Humans ; Lamivudine ; pharmacology ; Pseudocowpox Virus ; Tumor Cells, Cultured ; Virus Replication ; drug effects ; Zidovudine ; pharmacology

In addition to immune regulation, interferon could suppress hepatitis B virus (HBV) replication through direct antiviral effect. After binding with the receptors on cell membrane, interferon directly inhibits HBV at different steps in HBV replication cycle by activating cell signaling cascades such as JAK-STAT pathway, interferon regulatory factor (IRFs) signaling pathway, and so on, followed by inducing a series of cytokines which are involved in regulation of the function of HBV enhancer I / X promoter (Ehn I / Xp). Also, interferon could induce the host cells to produce anti-viral proteins. This review describes the direct antiviral mechanism of interferon on HBV.
Animals ; Antiviral Agents ; pharmacology ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Interferons ; classification ; pharmacology ; Signal Transduction ; drug effects ; Virus Replication ; drug effects

The influenza A is an acute respiratory infection persistently threatening human health and social stability, and has caused high morbidity and mortality. The development of novel anti-influenza drugs based on new targets is very significant because of high mutation and drug resistance of influenza virus. The nucleoprotein of influenza A virus identified high conservation, provides cross immune protection as a potential target of anti-influenza drugs and reports on relevant studies have been published at home and a- board. Herbal drug as a traditional Chinese medicine shows the distinct advantages in the aspect of prevention and treatment of influenza A. This paper analyzes the structure and function of influenza a virus, and reviews the advances in the research on anti-influenza targets based on the nucleoprotein of the influenza A virus.
Animals ; Drug Discovery ; methods ; Humans ; Influenza A virus ; drug effects ; metabolism ; physiology ; Influenza, Human ; drug therapy ; Molecular Targeted Therapy ; methods ; Nucleoproteins ; chemistry ; metabolism ; Virus Replication ; drug effects

OBJECTIVETo explore the effects of the extract from Phyllanthus urinaria L. on hepatitis B virus (HBV) replication and expression in HBV transient transfection model in vitro.

METHODSThe eukaryotic expression plasmid pHBV1.1, which contains 1.1-fold-overlength genome of HBV, was transfected into the human hepatoma cell line, HepG2, to establish and assess the HBV transient transfection model. The extract from Phyllanthus urinaria L. was prepared in different concentrations and methyl thiazolyl tetrazolium was used to detect the maximum nontoxic concentration of the drug. The extract from Phyllanthus urinaria L. were added into the transfected cell, at the concentrations of 0.8, 0.2 and 0.05 g/L, respectively. Four days after drug application, enzyme-linked immuno sorbent assay was used to detect the concentration of HBsAg in the supernatants, Southern blot was applied to analyze HBV DNA level, and Western blot was used to detect the expression of HBcAg in cells.

RESULTSAfter the transfection of plasmid pHBV1.1 into HepG2 cells, the concentration of HBsAg in supernatants was increased obviously as compared with that of the normal cells (P<0.05), and all expected HBV replicative intermediates were confirmed by Southern blot analysis, which ensured the successful establishment of the HBV transient transfection model. After the application of drugs at the concentrations of 0.8 and 0.2 g/L, the level of HBsAg was obviously decreased in the supernatants, as compared with that of the virus group (P<0.05); Southern blot showed that the level of HBV rc DNA, ds DNA, ss DNA was obviously reduced compared with that of the virus group (P<0.01); Western blot revealed that the expression of HBcAg in the drug group was obviously inhibited, as compared with that of the virus group (P<0.01).

CONCLUSIONSThe extract from Phyllanthus urinaria L. obviously inhibited replication and expression of HBV in HBV transfected cell lines in vitro, thus exerting distinctive anti-HBV effects.

Hep G2 Cells ; Hepatitis B ; drug therapy ; Hepatitis B virus ; drug effects ; physiology ; Humans ; Phyllanthus ; Plant Extracts ; pharmacology ; Transfection ; Virus Replication ; drug effects

BACKGROUNDTo determine the feasibility of inhibition of duck hepatitis B virus (DHBV) DNA replication by antisense phosphorothioate oligodeoxynucleotides corresponding to DHBV transcription region.

METHODSThe authors designed three antisense phosphorothioate oligodeoxynucleotides which correspond to DHBV PreS1,PreS2 and S antigen gene promotors respectively. The DNA replication level was detected with Southern blot method and cpm calculation.

RESULTSPrimary duck hepatocyte culture was treated with 1.5 micromol/L antisense oligodeoxynucleotides in vitro, all the antisense fragments caused a firm inhibition of viral DNA replication and the inhibition rates were 61.5%, 69.3% and 62.4%, respectively. In vivo, the animals were treated with 10 microgram/g PreS1 antigen gene promotor antisense oligodeoxynucleotides per day for 6 days and a very strong inhibition rate of 87.9% was obtained.

CONCLUSIONSThe results demonstrated the potential clinical application of antisense phosphorothioate oligodeoxynucleotides in clinics.

Animals ; DNA Replication ; drug effects ; DNA, Viral ; drug effects ; Ducks ; Hepadnaviridae Infections ; virology ; Hepatitis B Surface Antigens ; blood ; Hepatitis B Virus, Duck ; genetics ; physiology ; Hepatitis, Viral, Animal ; virology ; Oligodeoxyribonucleotides, Antisense ; pharmacology ; Protein Precursors ; blood ; Virus Replication ; drug effects