Betacoronavirus ; isolation & purification ; pathogenicity ; Bile Acids and Salts ; metabolism ; Bile Ducts, Intrahepatic ; pathology ; virology ; Cell Culture Techniques ; Coronavirus Infections ; complications ; pathology ; Cytokine Release Syndrome ; etiology ; physiopathology ; Cytopathogenic Effect, Viral ; Epithelial Cells ; enzymology ; pathology ; virology ; Humans ; Hyperbilirubinemia ; etiology ; Liver ; pathology ; Organoids ; pathology ; virology ; Pandemics ; Peptidyl-Dipeptidase A ; analysis ; Pneumonia, Viral ; complications ; pathology ; Receptors, Virus ; analysis ; Serine Endopeptidases ; analysis ; Viral Load

Enterovirus 71 is a neuroinvasive virus that is associated with severe neurological complications. We had earlier suggested that the replication capacity of a severe strain was higher than that of a mild strain. The recombinant 3CRV and 3CDRV virus strains were successfully rescued in our previous study. In the present study, we found no difference in virulence between 3CRV and severe strains. However, the capacity of replication and to cause cell injury of 3CDRV strain decreased in vitro, especially at 39.5 °C. Replacement of 3CD region in the severe strain led to milder symptoms, less body weight loss, and lower viral load in ICR mice. Histopathological findings indicated less severe injury in mice infected with 3CDRV strain. This study suggests that the 3CD region contributes to the attenuation of the severe strain, including its replication capacity and temperature sensitivity.
Animals ; Cytopathogenic Effect, Viral ; Enterovirus A, Human ; genetics ; pathogenicity ; Enterovirus Infections ; pathology ; virology ; Gene Expression Regulation, Viral ; Mice ; Mice, Inbred ICR ; Mutation ; Viral Load ; Viral Proteins ; genetics ; metabolism ; Virulence ; Virus Replication

During a search for neuraminidase inhibitors derived from medicinal fungi, we found that the fermentation broth of Phellinus linteus exhibited potent neuraminidase inhibitory activity. Through bioassay-guided fractionation, two active compounds were purified from the ethyl acetate-soluble portion of the fermentation broth of P. linteus. These structures were identified as inotilone (1) and 4-(3,4-dihydroxyphenyl)-3-buten-2-one (2) by spectroscopic methods. Compounds 1 and 2 inhibited H1N1 neuraminidase activity with IC50 values of 29.1 and 125.6 microM, respectively, in a dose-dependent manner. They also exhibited an antiviral effect in a viral cytopathic effect reduction assay using MDCK cells. These results suggest that compounds 1 and 2 from the culture broth of P. linteus would be good candidates for the prevention and therapeutic strategies towards viral infections.
Cytopathogenic Effect, Viral ; Fermentation* ; Fungi ; Inhibitory Concentration 50 ; Madin Darby Canine Kidney Cells ; Neuraminidase*

This research aims to evaluate the application of Real - time cell assay (RTCA) based on microelectronics sensor technology in the detection of HEV71 induced cell lesion. Growth indexes of RD cells at different stages were observed dynamically, appropriate cell concentration was selected to test HEV71 infectivity and to determine the HEV71 neutralizing antibody titer in serum. The traditional microplate test was used as methodology comparison and results validation at the same time. Cell impedance was transformed to cell index (CI) value and visual dynamic curve through software, and the result showed that the observation of HEV71 infectivity was more than 5d when the RD cells concentration was 1. 5 X 10(4) hole on the 96 electronic orifice plate. Compared with the traditional cytopathic effect (CPE) through microscope observation method, the end point judgment results were consistent between these two methods at 132h (about 5. 5d) post virus inoculation. In the neutralization tests, three CI values of neutralizing antibody titers against HEV71 in human serum were correspond to those obtained from traditional 96 microplate microscopy. RTCA also suggested that the presentation time of CPE induced by the i virus could be different even the end point judgment was the same with the same neutralization antibody titer. Compared with the traditional microplate monitoring method, RTCA can save labor and eliminate the hands-on error in the monitoring HEV71 infectivity and antibody titer detection in serum. RTCA can be served as one of the supplementary methods of traditional detection method, with the advantages of dynamically observing the occurrence and development of cell pathological changes, and the variation of virus infectivity and serum neutralizing antibodies.
Antibodies, Neutralizing ; blood ; Antibodies, Viral ; blood ; Cell Line, Tumor ; Cytopathogenic Effect, Viral ; Electric Impedance ; Enterovirus A, Human ; immunology ; pathogenicity ; Enterovirus Infections ; virology ; Humans ; Microelectrodes ; Neutralization Tests ; methods

To study the proliferation characteristics of PPV in differently infected way and the variance of concentrations in different cells. A strain of porcine parvovirus(PPV) was adapted to PK-15 cells, and a Real-time fluorescent quantitative PCR (FQ-PCR) assay was developed based on the specific region of the NS1 gene of PPV to quantify the PPV. The FQ-PCR was used to measure the viral concentration of virus-infected cells by simultaneous or step by step inoculation and plot one-step growth curves. The proliferation characteristics of PPV strain in different cells lines (HeLa, MDBK, PK-15 ,ST, F81, BHK-21 and Marc-145) was also compared. The results showed the PK-15 cell -adapted strain of PPV produced CPE after 12 passages, and maintained stable CPE at the following 10 messages. The one-step growth curve showed that the virus concentration of simultaneous inoculation was higher than that of the step-by-step inoculation, and the proliferation cycle of step-by-step inoculation was shorter. The proliferation ability of PPV strain in different cells showed that CPE appeared first inPK-15, followed by ST, HeLa and MDBK, and the virus concentration was highest in ST, followed byPK-15, MDBK and HeLa. NO proliferation was observed in F81, BHK-21 and Marc-145 cells. These findings lay a material foundation for the basic researches on PPV and the development of vaccine.
Animals ; Cell Line ; Cricetinae ; Cytopathogenic Effect, Viral ; DNA, Viral ; genetics ; Female ; Haplorhini ; Humans ; Male ; Parvoviridae Infections ; virology ; Parvovirus, Porcine ; genetics ; physiology ; Real-Time Polymerase Chain Reaction ; Reproducibility of Results ; Sensitivity and Specificity ; Swine ; Viral Proteins ; genetics ; Virus Replication

This study is to report the preparation of complexes of Ad5 and anionic liposomes (AL-Ad5), the amplification of adenoviruses with enhanced green fluorescent protein (eGFP) reporter gene performed by HEK 293 cells, the adenoviral vectors purified by cesium chloride gradient centrifugation, and the titer of adenovirus determined by cytopathic effect (CPE) method, hexon capsid immunoassay and quantitative-PCR (Q-PCR), separately. The prescription and experiment conditions were optimized by central composite design (CCD). The complexes of Ad5 and AL-Ad5 were formulated by the calcium-induced phase change method. The morpholopy, particle size and zeta potential were detected by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Additionally, the bicolourable fluoresce-labeled complexes (F(labeled)-AL-Ad5) were prepared and their intracellular location in MDCK cells was detected by confocal laser scanning microscopy (CLSM). The results indicate that the complexes of AL-Ad5 exhibited a uniform distribution with a particle size of 211 +/- 10 nm and a zeta potential of -41.2 +/- 2.2 mV. The result of CLSM demonstrates that the intracellular location of red fluoresce-labeled adenovirus was consistent with that of green fluoresce-labeled liposomes suggesting that the naked adenovirus was well encapsulated by the anionic liposomes in complexes of AL-Ad5.
Adenoviridae ; genetics ; ultrastructure ; Animals ; Anions ; Cytopathogenic Effect, Viral ; Dogs ; Drug Compounding ; methods ; Genetic Vectors ; Green Fluorescent Proteins ; chemistry ; HEK293 Cells ; Humans ; Liposomes ; chemistry ; pharmacokinetics ; ultrastructure ; Madin Darby Canine Kidney Cells ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Particle Size ; Polymerase Chain Reaction ; methods ; Recombinant Fusion Proteins ; ultrastructure

To investigate biological characteristics of the IVpi-189 progeny virus derived from the culture of influenza A virus as a live-attenuated vaccine candidate. Persistent infection of a cultured cell line with influenza A virus (MDCK-IVpi) was established by incubating continuously influenza virus-infected cells at a lower temperature. The infectious progeny virus derived from MDCK-IVpi cells at the 189rd subculture was designated as the IVpi-189 strain of influenza virus. The cytopathic effect induced by IVpi-189 virus was observed under different temperature conditions. The production of infectious progeny virus was examined at 38 and 32 degrees C by plaque titration of cell-associated and released virus. IVpi-189 virus showed cytopathic effect as strong as that of IVwt in infected cell line of MDCK at 32 degrees C. However, when culture temperature was raised to 38 degrees C, the cytopathic effect induced by IVpi-189 virus was delayed and less pronounced. Virus growth in IVpi-189 virus-infected cells at 38 degrees C was significantly reduced as compared with that of IVwt virus, although both viruses yielded nearly equivalent high titers of cell-associated and released virus at 32 degrees C. The reasons of the decreased proliferative ability of IVpi-189 virus at high culture temperature were unrelated with virus inactivation or the release of progeny virus, but associated with the decreased replication of infectious progeny virus in the infected cells. IVpi-189 virus derived from MDCK cells infected persistently with influenza A virus showed biological characteristics as a potential live-attenuated vaccine candidate.
Animals ; Cell Line ; Cytopathogenic Effect, Viral ; Dogs ; Humans ; Influenza A virus ; genetics ; physiology ; Temperature ; Virus Cultivation ; methods ; Virus Replication

Human rhinoviruses (HRVs) are the causative pathogens in more than half of viral upper respiratory tract infections. Currently, no antiviral agents that are active against HRVs are available for clinical use. Because only higher primates are susceptible to HRVs, the screening of new drug is most commonly based on the cell line model. In this study, isolated rabbit airway smooth muscles (ASM) tissue model has been established, and the airway responsiveness with different treatment has been examined. Relative to control tissues, the maximal constrictor (Tmax) response to ACh increased significantly 150% in ASM inoculated with HRV, and relaxation to isoproterenol has been attenuated to 63%. And the abnormal responsiveness can be inhibited in presence of pretreatment with several new compounds which have been exhibited effective anti-HRV activity on cell lines. The results demonstrate that the established ASM model will be applied to screening the anti-HRVs drugs.
Acetylcholine ; pharmacology ; Animals ; Antiviral Agents ; pharmacology ; Cytopathogenic Effect, Viral ; drug effects ; HeLa Cells ; Humans ; Isoproterenol ; pharmacology ; Muscle Contraction ; drug effects ; Muscle Relaxation ; drug effects ; Muscle, Smooth ; drug effects ; physiopathology ; virology ; Piperidines ; pharmacology ; Pyridazines ; pharmacology ; Rabbits ; Rhinovirus ; Trachea ; drug effects ; physiopathology ; virology

OBJECTIVETo perform gene expression profiles comparison so that to identify and understand the potential differences in pathogenesis between the pandemic and seasonal A (H1N1) influenza viruses.

METHODSA549 cells were infected with A/California/07/09 (H1N1) and A/GuangdongBaoan/51/08 (H1N1) respectively at the same MOI of 2 and collected at 2, 4, 8, and 24 h post infection (p.i.). Gene expression profiles of A549 cells were obtained using the 22 K Human Genome Oligo Array, and differentially expressed genes were analyzed at selected time points.

RESULTSMicroarrays results indicated that both of the viruses suppressed host immune response related pathways including cytokine production while pandemic H1N1 virus displayed weaker suppression of host immune response than seasonal H1N1 virus. Observation on similar anti-apoptotic events such as activation of apoptosis inhibitor and down-regulation of key genes of apoptosis pathways in both infections showed that activities of promoting apoptosis were different in later stage of infection.

CONCLUSIONSThe immuno-suppression and anti-apoptosis events of pandemic H1N1 virus were similar to those seen by seasonal H1N1 virus. The pandemic H1N1 virus had an ability to inhibit biological pathways associated with cytokine responses, NK activation and macrophage recognition.

Apoptosis ; genetics ; Cell Line, Tumor ; Cytopathogenic Effect, Viral ; Disease Outbreaks ; Down-Regulation ; Epithelial Cells ; metabolism ; virology ; Gene Expression ; Gene Expression Profiling ; Humans ; Immunity, Innate ; genetics ; Influenza A Virus, H1N1 Subtype ; classification ; pathogenicity ; Influenza, Human ; epidemiology ; genetics ; immunology ; virology ; Oligonucleotide Array Sequence Analysis ; Pandemics ; Seasons ; Up-Regulation ; Virulence

To study in vitro anti-influenza viral activities of Chinese traditional patent medicines for influenza prevention and treatment, neuraminidase (NA) activity assay was used to examine NA inhibitory activity of 33 Chinese traditional patent medicines through fluorimetric assay, and influenza virus induced cytopathic effect (CPE) inhibition assay was used to verify their anti-influenza viral activities in vitro. The assay results showed that most liquid preparations displayed relatively high NA inhibitory activities, such as Shuanghuanglian oral liquid, Qingkailing oral liquid, Qingre Jiedu oral liquid, and Reduning injection. Among liquid preparations, Shuanghuanglian oral liquid not only displayed the highest NA inhibitory effect, but also exhibited obvious in vitro anti-viral activity in CPE experiment. Among solid preparations, Shuanghuanglian powder for injection showed the highest activity on NA inhibition, and Fufang Yuxingcao tablet showed relatively strong anti-influenza viral activity in CPE cells. From the results, it can be concluded that most Chinese traditional patent medicines possessed NA inhibitory activity, but only a few of them displayed significant in vitro anti-influenza viral activities. These results will provide important information for the isolation of active constituents, and for the clinical uses of Chinese traditional patent medicines for influenza treatment and prevention.
Animals ; Antiviral Agents ; pharmacology ; Cell Line ; Cytopathogenic Effect, Viral ; drug effects ; Dogs ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Influenza A Virus, H1N1 Subtype ; drug effects ; enzymology ; Influenza A Virus, H3N2 Subtype ; drug effects ; enzymology ; Influenza B virus ; drug effects ; enzymology ; Medicine, Chinese Traditional ; Neuraminidase ; antagonists & inhibitors ; metabolism ; Plants, Medicinal ; chemistry