Characterization of the infectivity of an Indonesian Zika virus strain in mammalian cell lines

Objective:To characterize the infection patterns and growth characteristics of the Zika virus(ZIKV)strain JMB-185 from Indonesia in various mammalian cell lines.Methods:ZIKV was grown in human(A549,HEK293,HepG2,Huh7,Jurkat,and THP-1)and non-human mammalian(RAW264.7,Vero,and Vero76)cell lines.Viral replication kinetics were measured using plaque assay,while intra-and extracellular viral RNA concentrations were assessed using RT-PCR.Flow cytometry was used to quantify the infected cells and cell viability was measured using an MTT assay.The ability of ZIKV to infect cell lines was visualized using a fluorescence immunostaining assay.Results:This ZIKV strain preferentially infected the lung,kidney,and liver cell lines A549,HEK293,Huh7,Vero,and Vero76,but not the immune cells Jurkat,RAW264.7,and THP-1.By contrast,the ZIKV showed no sign of infection in HepG2 cells,while maintaining viral titer over 3 days post-infection,with no infection recorded in immunostaining,no increase in viral RNA,and no indication of cell deterioration.Conclusions:The Indonesian ZIKV strain has a similar infection profile as other strains,except for its poor infectivity on HepG2 cells.Information on the growth characteristics of Indonesia ZIKV will help expand our understanding of the biology of ZIKV which will be useful for various applications including antiviral discovery.

Effect of pre-culture on virus elimination from in vitro apple by thermotherapy coupled with shoot tip culture

We evaluated the role of pre-culture on survival rate of in vitro apple plants treated by thermotherapy. Two apple cultivars, Malusxdomestica cv. Pink Lady and Huafu, were used in the experiment and both have widely grown in China and infected with Apple chlorotic leafspot virus （ACLSV） and Apple stem grooving virus （ASGV）. Results in growth and virus titer of apple plants did not exhibit clear trends during five different periods of pre-culture. Whilst, pre-culture increased the survival rate of the two cultivars during thermotherapy. The survival rate of plants pre-cultured for 13 d （P-13d） was 14 and 51% higher than that of P-ld plants for Pink Lady and Huafu, respectively. Moreover, pre-culture positively influenced regeneration of Huafu plants. The average survival rate of plants regenerated from P-ld and P-4d was 20% lower than that regenerated from P-7d, P-10d, and P-13d. The efficiency of virus eradication was determined by reverse-transcription PCR with two primer pairs for each virus, and the detection results showed that pre-culture scarcely affected apple virus elimination. Despite the fact that the two viruses were hardly detected at 5 d of thermotherapy, no virus-free plants were found in the two cultivars of regenerated apple plantlets after 30-d treatment.

HepG2 cells support viral replication and gene expression of hepatitis C virus genotype 4 in vitro

瞄准：与丙肝的长期的复制建立一个房间文化系统病毒(HCV ) 染色体和病毒的抗原的表示在试管内。方法：HepG2 房间线被孵化与长期的丙肝从一个病人与浆液为它的危险性测试到 HCV。房间和上层清液在文化期间在各种各样的时间点被收获。文化上层清液为它感染天真的房间的能力被测试。存在减(反感觉) 在房间的核心和 E1 抗原的 RNA 海滨，和察觉被 RT-PCR 和免疫学的技术(流动血细胞计数和西方的污点) 分别地检验。结果：细胞内部的 HCV RNA 首先在 d 上被检测 3 在感染以后然后能一致地在至少三个月的一个时期上在房间和上层清液被检测。新鲜房间能从有教养的感染的房间感染上层清液。流动 cytometric 分析证明表面和在房子里使用的细胞内部的 HCV 抗原表示使 polyclonal 成为了抗体(反核心，和 anti-E1 ) 。西方的污点分析证明在分子量的产生免疫性的肽的簇的表示在一个月内在 31 和 45 kDa 之间延长了感染的房间的旧文化而这簇在 uninfected HepG2 房间是无法发现的。结论：HepG2 房间线产生 HCV 感染而且支持它的复制在试管内不仅。HCV 结构的蛋白质的表示能在感染的 HepG2 房间被检测。这些房间也能够流病毒的粒子进接着对 uninfected 房间变得传染的培养基。

Cryptoporic acid E from Cryptoporusvolvatus inhibits influenza virus replication in vitro

Influenza virus infection is a global public health issue.The effectiveness of antiviral agents for influenza has been limited by the emergence of drugresistant virus strains.Therefore,there is an urgent need to identify novel antiviral therapies.Our previous studies have found that Cryptoporus volvatus extract could potently inhibit influenza virus replication in vitro and in vivo.However,the effective component of Cryptoporus volvatus which mediated the antiviral activity hasn′t been identified.Here,we identified a novel anti-influenza molecule,cryptoporic acid E(CAE),from Cryptoporus volvatus.Our results showed that CAE had broad-spectrum anti-influenza activity against 2009 pandemic strain A/Beijing/07/2009(H1N1/09),seasonal strain A/Jiangxi/262/05(H3N2),mouse adapted strains A/WSN/33(H1N1)and A/PR8/34(H1N1).We further investigated the mode of CAE action,and found that CAE directlyattenuated influenza virus infectivity.Time-course-analysis indicated that CAE exerted its inhibition mainly at middle stage of the replication cycle of influenza virus.Subsequently,we confirmed that CAE blocked virus RNA replication and transcription in MDCK cells and CAE repressed influenza virus RNA polymerase activity.In addition,we found that CAE impaired influenza virus infectivity by directly targeting virus particles.Our data suggest that CAE is a major effective component of Cryptoporus volvatus and might be a potential candidate for the development of a new anti-influenza virus therapy.

Hepatitis C virus infection of human hepatoma cell line 7721 in vitro

AIM To establish a cell culture system with long-term replication of hepatitis C virus in vitro.``METHODS Human hepatoma cell line 7721 was tested for its susceptibility to HCV by incubating with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various phases during the culturing periods The presence of HCV RNA, the expression of HCV antigens in cells and/or supernatant were examined by RT-PCR, in situ hybridization and immunohistochemistry respectively.``RESULTS The intracellular HCV RNA was first detected on d 2 after infection and then could be intermittently detected in both cells and supernatant over a period of at least three months. The expression of HCV NS3, CP10antigens could be observed in cells. The fresh cells could be infected by supematant from cultured infected cells and the transmission of viral genome from HCV-infected 7721 cells to PBMCs was also observed.``CONCLUSION The hepatoma line 7721 is not only susceptible to HCV but also supports its long-term replication in vitro.

Synthesis and Anti-influenza Virus Activity of Ethyl 6-Bromo-5-hydroxyindole-3-carboxylate Derivatives

A series of ethyl 6-bromo-5-hydroxyindole-3-carboxylate derivatives were synthesized and their in vitro anti-influenza virus activity was evaluated. All the compounds were characterized by 1H NMR and MS.

ELECTRON MICROSCOPIC OBSERVATION OF SIMIAN SARCOMA VIRUS TRANSFORMED NIH 3T3 CELLS IN VITRO

For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ribosomes (polyribosomes were attached to the swollen rough endoplasmic reticulum. It was likely that ribosomes were lined together functionally and structionally to produce specific protein (PDGF-like protein).

Study on the in vitro activity of Hehuan Yin aqueous extract against hepatitis C 2a virus

Objective:To study the anti-HCV activity and mechanism of Hehuan Yin aqueous extract.Methods:Huh7.5.1 cells were used to establish the HCV2a virus infection model.Cell survival rate(%)and Renilla Luciferase Assay Kit(%)were calculated by Celltiter-GLO Assay for evaluating CC50,EC50 and SI values.To observe the drug resistance of the virus to different concentrations of Hehuan Yin within 72 hours by detecting luciferase activity,western-blot was used to detect the protein expression levels of NS5A,NS3 and NS5B.Results:the CC50,EC50 and SI of Hehuan Yin against HCV2a were 132.50g/ml,1.90g/ml and 67.90 respectively.The EC50 after 24h,48h and 72h administration were 18g/ml,5.8g/ml and 2.3g/ml respectively.Within the range of drug concentration,the aqueous extract Hehuan Yin had inhibitory effect on the expression of NS5A and NS5B proteins in a dose-effect relationship,but had no obvious effect on the expression of NS3 protein.Conclusion:The aqueous extract of Hehuan Yin may inhibit the replication of HCV2a virus by changing the protein expression levels of NS5A and NS5B,and the virus has no tolerance to the aqueous extract of Hehuan Yin.

Hepatitis C virus in human B lymphocytes transformed by Epstein-Barr virus in vitro by in situ reverse transcriptase-polymerase chain reaction

AIM To study persistence and replication ofheltitis C virus (HCV) in patients' peripheralblood mononuclear cells (PBMC) cultured invitro.METHODS Epstein-Barr virus (EBV) was usedto transform the hepatitis C virus from a HCVpositive patient to permanent lymphoblastoidcell lines (LCL). Positive and negative HCV RNAstrands of the cultured cells and growth mediawere detected by reverse transcriptase-polymerase chain reaction ( RT-PCR ) eachmonth. Core and NS5 proteins of HCV werefurther tested using immunohistochemical SPmethod and in situ RT-PCR.RESULTS HCV RNA positive strands wereconsistently detected the cultured cells for oneyear. The negative-strand RNA in LCL cells andthe positive-strand RNA in supernatants wereobserved intermittently. Immunohistochemicalresults medicated expression of HCV NS3 and Cproteins in LCL cytoplasm mostly. The positivesignal of PCR product was dark blue and mainlylocalized to the LCL cytoplasm. The RT-PCRsignal was eliminated by overnight RNasedigestion but not DNase digestion.CONCLUSION HCV may exist and remainfunctional in a cultured cell line for a longperiod.

Expression of hepatitis B virus genes in early embryonic cells originated from hamster ova and human spermatozoa transfected with the complete viral genome

Aim： To detect the expression of hepatitis B virus （HBV） genes （HB S and C genes） in early embryonic cells after introducing motile human sperm carrying HBV DNA into zona-free hamster oocytes via the in vitro fertilization （IVF） technique. Methods： Human sperm-mediated HBV genes were delivered into zona-free hamster oocytes by the IVF method. Polymerase chain reaction （PCR） was used to detect HB S and pre-Core/Core （pre-C/C） coding genes both in one- and two-cell embryos. Reverse transcription-PCR （RT-PCR） analysis was used to study the expression of the two genes. Fluorescence in situ hybridization （FISH） analysis using the full-length HBV DNA as the hybridization probe was performed to confirm the integration of viral DNA in the host embryonic genome. Results： Both HB S and pre-C/C coding genes are present and transcribed in one- and two-cell embryos originated from hamster ova IVF with human spermatozoa carrying HBV DNA sequences. Conclusion： Sperm-mediated HBV genes are able to replicate and express themselves in early embryonic cells. These results provide direct evidence that HBV DNA could transmit vertically to the next generation via the male germ line.

Hepatitis C virus: Morphogenesis, infection and therapy

Hepatitis C virus(HCV) is a major cause of liver diseases including liver cirrhosis and hepatocellular carcinoma. Approximately 3% of the world population is infected with HCV. Thus, HCV infection is considered a public healthy challenge. It is worth mentioning, that the HCV prevalence is dependent on the countries with infection rates around 20% in high endemic countries. The review summarizes recent data on HCV molecular biology, the physiopathology of infection(immune-mediated liver damage, liver fibrosis and lipid metabolism), virus diagnostic and treatment. In addition, currently available in vitro, ex vivo and animal models to study the virus life cycle, virus pathogenesis and therapy are described. Understanding of both host and viral factors may in the future lead to creation of new approaches in generation of an efficient therapeutic vaccine.

Generation of Recombinant Equine Influenza Vaccine Candidate RgH3N1 Virus by Reverse Genetics

The antigenic variation of influenza A virus hemagglutinin (HA) glycoproteins requires frequent changes in vaccine formulation. The new strategy of creating influenza seed strains for vaccine production is to generate 7 + 1 reassortants that contain seven genes from a high-yield virus A/Puerto Rico/8/34[A/PR/8/34](H1N1) and the HA gene from the circulating strains. By using this DNA-based cotransfection technique, we generated 7 + 1 reassortants rgH3N1 which had the antigenic determinants of influenza virus A/Songbird/HongKong/102/00[SB/HK/01](H3N8) and 7 other genes from A/PR/ 8/34. The hemagglutinin of A/Songbird/HongKong/102/00 is 96.3% homologous to that of A/Equine/Jilin/98[Eq/Jl/89] (H3N8). The resulting virus rgH3N1 grows to high HA titers in chicken embryonated eggs, allowing vaccine preparation in unconcentrated allantoic fluid. The rgH3N1 is stable after multiple passages in embryonated eggs. The reassortant rgH3N1 virus could be used as vaccine candidate to reduce the reemergence of equine influenza outbreaks.

Trans-cleaving activity of hepatitis delta virus genomic ribozymes

Objective: To study whether 2 hepatitis delta virus genomic ribozymes(g. Rz) have trans-cleaving activity. Methods: g. Rz74 and g. Rz55 were transcribed from their templates which were synthesized and cloned into plasmid pGEM-4Z; Homologous substrate RNA was transcribed for pRz277B and labelled withα-32 P-UTP. The trans-cleaving activity was studied by mixing the ribozymes and substrate in appropriate who under certain conditions. Results: The trans-cleaved products were generated after mixing the ribozyme with the substrate for 30 min, and accumulated more for 90 min. Conclusion: Both g. Rz74 and g. Rz55 possess trans-cleaving activity.

Multi-Omics-Guided Discovery of Omicsynins Produced by Streptomyces sp.1647:Pseudo-Tetrapeptides Active Against Influenza A Viruses and Coronavirus HCoV-229E

Many microorganisms have mechanisms that protect cells against attack from viruses.The fermentation components of Streptomyces sp.1647 exhibit potent anti-influenza A virus(IAV)activity.This strain was isolated from soil in southern China in the 1970s,but the chemical nature of its antiviral substance(s)has remained unknown until now.We used an integrated multi-omics strategy to identify the antiviral agents from this streptomycete.The antibiotics and Secondary Metabolite Analysis Shell(antiSMASH)analysis of its genome sequence revealed 38 biosynthetic gene clusters(BGCs)for secondary metabolites,and the target BGCs possibly responsible for the production of antiviral components were narrowed down to three BGCs by bioactivity-guided comparative transcriptomics analysis.Through bioinformatics analysis and genetic manipulation of the regulators and a biosynthetic gene,cluster 36 was identified as the BGC responsible for the biosynthesis of the antiviral compounds.Bioactivity-based molecular networking analysis of mass spectrometric data from different recombinant strains illustrated that the antiviral compounds were a class of structural analogues.Finally,18 pseudo-tetrapeptides with an internal ureido linkage,omicsynins A1–A6,B1–B6,and C1–C6,were identified and/or isolated from fermentation broth.Among them,11 compounds(omicsynins A1,A2,A6,B1–B3,B5,B6,C1,C2,and C6)are new compounds.Omicsynins B1–B4 exhibited potent antiviral activity against IAV with the 50%inhibitory concentration(IC_(50))of approximately 1μmol·L^(-1)and a selectivity index(SI)ranging from 100 to 300.Omicsynins B1–B4 also showed significant antiviral activity against human coronavirus HCoV-229E.By integrating multi-omics data,we discovered a number of novel antiviral pseudo-tetrapeptides produced by Streptomyces sp.1647,indicating that the secondary metabolites of microorganisms are a valuable source of novel antivirals.

Experimental study on pharmacodynamics of pudilan xiaoyan oral liquid for preventing and treating respiratory virus infection

Background:Pudilan Xiaoyan Oral Liquid(PDL),a famous traditional Chinese formula for treating acute and chronic inflammation.To evaluate the broad-spectrum antiviral effect of Pudilan Xiaoyan Oral Liquid,and provide a basis for clinical medication.Methods:Its inhibitory effect on different respiratory viruses was observed by cytopathic test.The potential mechanism of the anti-influenza effect was determined by neuraminidase activity.In order to observe the therapeutic effect of PDL on viral pneumonia caused by different respiratory viruses.The viral pneumonia model was established by nasal infection with different respiratory viruses,and then PDL was given Therapeutic and prophylactically to evaluate its pharmacodynamic activity in vivo.Results:The results of in vitro experiments showed that PDL had different inhibitory effects on cytopathic effects caused by different respiratory viruses.And it has obvious inhibitory effect on the neuraminidase activity of influenza A virus,which indicates that it exerts anti-influenza virus effect by inhibiting neuraminidase activity of influenza virus.The results in vivo showed that PDL exhibited an inhibitory effect on pulmonary index(PI)and effectively reduced the degree of lesions in the lungs.The lethal rate of mice was significantly decreased while survival time of mice was dramatically increased by PDL treatment in comparison to infection control,respectively.Conclusions:Our study demonstrates that PDL had a significant protection and treatment effect for respiratory virus infection in vitro and in vivo.

Elimination of grapevine fleck virus and grapevine rupestris stem pitting-associated virus from Vitis vinifera 87-1 by ribavirin combined with thermotherapy

Vitis vinifera 87-1 plants infected by grapevine fleck virus(GFkV) and grapevine rupestris stem pitting-associated virus(GRSPaV) were used as the plant materials for virus elimination treatment. This study evaluated the effects of ribavirin at different concentrations(15 and 25 μg mL^(–1);R15 and R25, respectively), thermotherapy(37°C;T), and the combination of ribavirin and thermotherapy(R15+T and R25+T) on eliminating viruses from grapevine plants in vitro. Both R15 and R25 had phytotoxic effects and weakened plant growth. Thermotherapy positively affected the growth of grapevine plants. Plant height was significantly greater in T, R15+T, and R25+T than in CK, R15 and R25. The proportion of dead plants after T, R15+T, and R25+T was 51.4, 11.4, and 8.6%, respectively. The survival rates of regenerated plants after all treatments were >68.0%. Ribavirin concentration and treatment time were related to the regeneration of shoot tips and elimination efficiencies of the two viruses. The survival rates of plants after R15+T for 30, 40, and 50 days were 97.3, 90.7, and 74.4%, respectively. The elimination rates of GRSPaV from plants in the three time quantum were 55.6, 84.6, and 93.8%, respectively. The elimination rate of GFkV was 23.9% higher in R25(35/44) than in R15(25/45), and that of GRSPaV was 7.0% higher in R25 than in R15. The combination of thermotherapy and chemotherapy was found to have a positive effect on the eradication of GFkV and GRSPaV, and R25+T for 50 days was able to completely eliminate the two viruses from in vitro grapevines.

Study on Virus-free and Rapid Propagation Technology of Artemisia selengensis sp.in Yangxin County

[Objectives]This study was conducted to culture virus-free tissue culture plantlets of mid-maturing green-stalk Artemisia selengensis sp.varieties in Yangxin County.[Methods]With bud tips of A.selengensis in Yangxin as explants and MS as the basal medium,screening and proportioning of plant growth regulators were performed to establish a virus-free and rapid propagation system for mid-maturing green-stalk varieties of A.selengensis in Yangxin.[Results]The optimal callus induction medium,adventitious shoot differentiation medium,adventitious shoot elongation medium and rooting medium for explants were MS+6-BA 1.0 mg/L+NAA 0.5 mg/L+sucrose 25 g/L+agar 7 g/L,MS+6-BA 0.1 mg/L+NAA 0.1 mg/L+sucrose 25 g/L+agar 7 g/L,MS+6-BA 0.02 mg/L+NAA 0.02 mg/L+sucrose 25 g/L+agar 7 g/L and 1/2 MS+NAA 0.05 mg/L+sucrose 25 g/L+agar 7 g/L,respectively,and the seedling rate reached more than 95%.The culture conditions were as follows:temperature(25±2)℃,relative humidity 85%,illumination intensity 3000 lx,and illumination time 14 h/d.[Conclusions]This study has important practical significance for the purification and rejuvenation and large-scale industrial breeding of Yangxin A.selengensis seedlings.

Potato Virus Y mRNA Expression Knockdown Mediated by siRNAs in Cultured Mammalian Cell Line

RNA interference(RNAi) is a powerful tool for functional gene analysis which has been successfully used to downregulate the expression levels of target genes.The goal of this research was to provide a highly robust and concise methodology for in-vitro screening of efficient siRNAs from a bulk to be used as a tool to protect potato plants against PVY invasion.In our study,a 480bp fragment of the capsid protein gene of potato virus Y(CP-PVY) was used as a target to downregulate PVY mRNA expression in-vitro,as the CP gene interferes with viral uncoating,translation and replication.A total of six siRNAs were designed and screened through transient transfection assay and knockdown in expression of CP-PVY mRNA was calculated in CHO-k cells.CP-PVY mRNA knockdown efficiency was analyzed by RT-PCR and real-time PCR of CHO-k cells co-transfected with a CP gene construct and siRNAs.Six biological replicates were performed in this study.In our findings,one CP gene specific siRNA out of a total of six was found to be the most effective for knockdown of CP-PVY mRNA in transfected CHO-k cells by up to 80%-90%.

Cell culture systems for the hepatitis C virus

Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consen- sus clones have been selected and established in a hu- man hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these repli- cons did not support production of infectious virus. Inter- estingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.

Design and activity evaluation of deoxyribozymes specifically targeting hepatitis C virus RNA

Objective: To explore the cleaving and inhibitory activity of hepatitis C virus (HCV)-specific deoxyribozymes (DRz) at both molecular and transgeneic cellular levels. Methods: According to the secondary structure of HCV 5′-noncoding region (5′-NCR) and the sites characterized with 5′…Y↓R...3′(Y=A/G,R=U/C), HCV-specific naive deoxyribozymes were designed and named DRz-232, DRz-127, DRz-84, DRz1, and the phosphorothioate deoxyribozymes (PSDRz) and mutated phosphorothioate deoxyribozymes (MPSDRz) were also designed. HCV RNA 5′-NCR was transcribed in vitro from linearized plasmid pHCV-neo and radiolabelled at its 5′-end. DRz, PSDRz or MPSDRz was respectively mixed with the substrate RNA and incubated under appropriate conditions, the cleaved products were displayed by 8% denaturated polyacrylamide gel electrophoresis (PAGE) and autoradiography, and the optical density of each band was measured to calculate cleavage rates. After that, every kind of DRz was added respectively to the cultured transgeneic HepG2 cells containing luciferase gene controlled by HCV 5′-NCR. The cells were lysed at intended time points and the activity of luciferase was measured with chemiluminescence method for calculating inhibition rates. Results: After incubated for 90 min in vitro, the cleavage rates of DRz-127, PSDRz-127, DRz1 and PSDRz1 reached 32.6%, 30.8%, 24.3% and 21.5%, respectively. No cleavage product was observed in any MPSDRz. DRz-127, PSDRz-127, DRz1 and PSDRz1 had an inhibitory rate of 53.2%, 50.6%, 44.7% and 43.3% respectively in transgeneic HepG2 cells in the first 24 h when the final dose of the DRz was 0.5 μmol/L, higher than that of the corresponding MPSDRz. There was no significant difference between the inhibitory effect of each DRz and its PSDRz in HepG2 cells, but the inhibitory rate of DRz decreased more rapidly than that of the latter with the elapse of time. The results from transfection groups were significantly better than those of non-transfection groups. Conclusion: Rationally-designed HCV-specific deoxyribozymes are able to cleave target RNA at molecular level in vitro, and efficiently inhibit the expression of luciferase gene controlled by HCV 5′-NCR in transgeneic cells. Appropriate PSDRz may be more stable, and thus more suitable than the naive DRz in the application to cells. Introduction of the deoxyribozymes with transfection is more efficient than with direct delivering ways.