scholarly journals Decanoyl-Arg-Val-Lys-Arg-Chloromethylketone: An Antiviral Compound That Acts against Flaviviruses through the Inhibition of Furin-Mediated prM Cleavage

Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1011 ◽  
Author(s):  
Imran ◽  
Saleemi ◽  
Chen ◽  
Wang ◽  
Zhou ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Mammalian Cells ◽  
Plaque Assay ◽  
Virus Titer ◽  
Vero Cells ◽  
Immunofluorescence Assay ◽  
Viral Rna ◽  
Antiviral Compound ◽  
Mosquito Cells ◽  
Infection Treatment

Flaviviruses, such as Zika virus (ZIKV), Japanese encephalitis virus (JEV), Dengue virus (DENV), and West Nile virus (WNV), are important arthropod-borne pathogens that present an immense global health problem. Their unpredictable disease severity, unusual clinical features, and severe neurological manifestations underscore an urgent need for antiviral interventions. Furin, a host proprotein convertase, is a key contender in processing flavivirus prM protein to M protein, turning the inert virus to an infectious particle. For this reason, the current study was planned to evaluate the antiviral activity of decanoyl-Arg-Val-Lys-Arg-chloromethylketone, a specific furin inhibitor, against flaviviruses, including ZIKV and JEV. Analysis of viral proteins revealed a significant increase in the prM/E index of ZIKV or JEV in dec-RVKR-cmk-treated Vero cells compared to DMSO-treated control cells, indicating dec-RVKR-cmk inhibits prM cleavage. Plaque assay, qRT-PCR, and immunofluorescence assay revealed a strong antiviral activity of dec-RVKR-cmk against ZIKV and JEV in terms of the reduction in virus progeny titer and in viral RNA and protein production in both mammalian cells and mosquito cells. Time-of-drug addition assay revealed that the maximum reduction of virus titer was observed in post-infection treatment. Furthermore, our results showed that dec-RVKR-cmk exerts its inhibitory action on the virus release and next round infectivity but not on viral RNA replication. Taken together, our study highlights an interesting antiviral activity of dec-RVKR-cmk against flaviviruses.

scholarly journals Silicon Nitride Inactivates SARS-CoV-2 in vitro

2020 ◽  
Author(s):  
Caitlin W. Lehman ◽  
Rafaela Flur ◽  
Kylene Kehn-Hall ◽  
Bryan J. McEntire ◽  
B. Sonny Bal ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Mammalian Cells ◽  
Aqueous Suspension ◽  
Bacterial Species ◽  
Plaque Assay ◽  
Treatment Strategies ◽  
Vero Cells ◽  
Growth Media ◽  
Minimal Impact

ABSTRACTIntroductionSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the COVID-19 pandemic, remains viable and therefore potentially infectious on several materials. One strategy to discourage the fomite-mediated spread of COVID-19 is the development of materials whose surface chemistry can spontaneously inactivate SARS-CoV-2. Silicon nitride (Si3N4), a material used in spine fusion surgery, is one such candidate because it has been shown to inactivate several bacterial species and viral strains. This study hypothesized that contact with Si3N4 would inactivate SARS-CoV-2, while mammalian cells would remain unaffected.MaterialsSARS-CoV-2 virions (2×104 PFU/mL diluted in growth media) were exposed to 5, 10, 15, and 20% (w/v) of an aqueous suspension of sintered Si3N4 particles for durations of 1, 5, and 10 minutes, respectively. Before exposure to the virus, cytotoxicity testing of Si3N4 alone was assessed in Vero cells at 24 and 48 hour post-exposure times. Following each exposure to Si3N4, the remaining infectious virus was quantitated by plaque assay.ResultsVero cell viability increased at 5% and 10% (w/v) concentrations of Si3N4 at exposure times up to 10 minutes, and there was only minimal impact on cell health and viability up to 20% (w/v). However, the SARS-CoV-2 titers were markedly reduced when exposed to all concentrations of Si3N4; the reduction in viral titers was between 85% - 99.6%, depending on the dose and duration of exposure.ConclusionsSi3N4 was non-toxic to the Vero cells while showing strong antiviral activity against SARS-CoV-2. The viricidal effect increased with increasing concentrations of Si3N4 and longer duration of exposure. Surface treatment strategies based on Si3N4 may offer novel methods to discourage SARS-CoV-2 persistence and infectivity on surfaces and discourage the spread of COVID-19.

scholarly journals Rapid Inactivation of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by Tungsten Trioxide-Based (WO3) Photocatalysis

2020 ◽  
Author(s):  
Silvia Ghezzi ◽  
Isabel Pagani ◽  
Guido Poli ◽  
Stefano Perboni ◽  
Elisa Vicenzi
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Tungsten Trioxide ◽  
Plaque Assay ◽  
Vero Cells ◽  
Viral Rna ◽  
Indoor Environments ◽  
Viral Plaque ◽  
Droplet Nuclei ◽  
Indoor Conditions ◽  
Respiratory Droplets

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), is transmitted person-to-person via respiratory droplets and, likely, via smaller droplet nuclei light enough to remain suspended in the air for hours and contaminate surfaces particularly in indoor conditions. Thus, effective measures are needed to prevent SARS-CoV-2 transmission in indoor environments. In this regard, we have investigated whether a system based on a filter combining Tungsten Trioxide-Based (WO3) photocatalysis and an antiviral fabric treated-copper nanocluster could inactivate SARS-CoV-2. To this purpose, an infectious SARS-CoV-2 suspension was introduced in the upper opening of a closed cylinder containing a WO3 filter and a lightbased system that activates WO3 and the antiviral fabric. From the bottom exit, aliquots of fluid were collected every 10 min (up to 60 min) and tested for their infectivity by means of a viral plaque assay in Vero cells whereas, in parallel, the viral RNA content was measured by quantitative PCR (qPCR). As we have previously shown for SARS-CoV, a 1:1,000 ratio of plaque forming units (PFU) vs. viral RNA copies was observed also for SARS-CoV-2. After 10 min, the infectious viral content was already decreased by 98.2% reaching 100% inactivation after 30 min whereas the SARS-CoV-2 RNA load was decreased of 1.5 log10 after 30 min. Thus, in spite of only a partial decrease of viral RNA, SARS-CoV-2 infectivity was completely abolished by the WO3 photocatalysis system by 30 min. These results support the hypothesis that this system could be exploited to achieve SARS-CoV-2 inactivation in indoor environments.

scholarly journals Chloroquine Inhibits Dengue Virus Type 2 Replication in Vero Cells but Not in C6/36 Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kleber Juvenal Silva Farias ◽  
Paula Renata Lima Machado ◽  
Benedito Antônio Lopes da Fonseca
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
Mammalian Cells ◽  
Plaque Assay ◽  
Antiviral Drug ◽  
Vero Cells ◽  
Significant Difference ◽  
Dengue Virus Type 2

Dengue viruses are the most important arthropod-borne viruses in terms of morbidity and mortality in the world. Since there is no dengue vaccine available for human use, we have set out to investigate the use of chloroquine as an antiviral drug against dengue. Chloroquine, an amine acidotropic drug known to affect intracellular exocytic pathways by increasing endosomal pH, was used in the in vitro treatment of Vero and C6/36 cells infected with dengue virus type 2 (DENV-2). Real-time RT-PCR and plaque assays were used to quantify the DENV-2 load in infected Vero and C6/36 cells after chloroquine treatment. Our results showed that a dose of 50 μg/ml of chloroquine was not toxic to the cells and induced a statistically significant inhibition of virus production in infected Vero cells when compared to untreated cells. In C6/36 cells, chloroquine does not induce a statistically significant difference in viral replication when compared to untreated cells, showing that this virus uses an unlikely pathway of penetration in these cells, and results were also confirmed by the plaque assay (PFU). These data suggest that the inhibition of virus infection induced by chloroquine is due to interference with acidic vesicles in mammalian cells.

scholarly journals The p59 oligoadenylate synthetase-like protein possesses antiviral activity that requires the C-terminal ubiquitin-like domain

2008 ◽  
Vol 89 (11) ◽  
pp. 2767-2772 ◽  
Author(s):  
Joao Marques ◽  
Jangawar Anwar ◽  
Signe Eskildsen-Larsen ◽  
Dominique Rebouillat ◽  
Soren R. Paludan ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Mammalian Cells ◽  
Rna Virus ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Encephalomyocarditis Virus ◽  
Synthetase Activity ◽  
Oligoadenylate Synthetase ◽  
Antiviral Protein ◽  
Herpes Simplex Virus 1

Viral infection of mammalian cells prompts the innate immune system to initiate an antiviral response. The recognition of the virus triggers several antiviral signalling pathways, which among others include the family of 2′-5′ oligoadenylate synthetase (OAS) proteins. The p59 protein encoded by the OAS-like (OASL) gene is an atypical member of the OAS family in the sense that it lacks the characteristic 2′-5′ oligoadenylate synthetase activity. We decided to investigate the putative antiviral activity of p59 by ectopically expressing this protein in Vero cells and then infecting these cells with virus. We demonstrate that OASL has an antiviral effect against the single-stranded RNA virus picornavirus, encephalomyocarditis virus, but not against a large DNA virus, herpes simplex virus 1. Importantly, this antiviral activity was lost in a truncated version of p59 lacking the ubiquitin-like C-terminal domain of p59. Taken together our results indicate that p59 is indeed an antiviral protein that works through a novel mechanism distinct from other OAS proteins.

scholarly journals Inhibition of Severe Acute Respiratory Syndrome Virus Replication by Small Interfering RNAs in Mammalian Cells

2004 ◽  
Vol 78 (14) ◽  
pp. 7523-7527 ◽  
Author(s):  
Zhi Wang ◽  
Lili Ren ◽  
Xingang Zhao ◽  
Tao Hung ◽  
Anming Meng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Mammalian Cells ◽  
Specific Treatment ◽  
Vero Cells ◽  
Viral Rna ◽  
Respiratory Syndrome Virus ◽  
Small Interfering Rnas ◽  
Protein Levels ◽  
Cytopathic Effects ◽  
Novel Coronavirus

ABSTRACT Severe acute respiratory syndrome (SARS) is an acute respiratory infectious disease that spread worldwide in early 2003. The cause was determined as a novel coronavirus (CoV), SARS-associated CoV (SARS-CoV), with a single-stranded, plus-sense RNA. To date, no effective specific treatment has been identified. To exploit the possibility of using RNA interference as a therapeutic approach to fight the disease, plasmid-mediated small interfering RNAs (siRNAs) were generated to target the SARS-CoV genome. The expression of siRNAs from two plasmids, which specifically target the viral RNA polymerase, effectively blocked the cytopathic effects of SARS-CoV on Vero cells. These two plasmids also inhibited viral replication as shown by titer assays and by an examination of viral RNA and protein levels. Thus, our results demonstrated the feasibility of developing siRNAs as effective anti-SARS drugs.

Intra and inter-cellular modeling of dynamic interaction between Zika virus and its naturally occurring defective viral genomes

2021 ◽  
Author(s):  
Vadim Sharov ◽  
Veronica V. Rezelj ◽  
Vladimir V. Galatenko ◽  
Avi Titievsky ◽  
Julia Panov ◽  
...  
Keyword(s):  
Virus Titer ◽  
Vero Cells ◽  
Mosquito Vector ◽  
Ns1 Protein ◽  
Coding Region ◽  
Viral Genomes ◽  
Naturally Occurring ◽  
Mosquito Cells ◽  
Infection Dynamics ◽  
Development Processes

Here we examine in-silico the infection dynamics and interactions of two ZIKV genomes: one is the full-length ZIKV genome (WT) and the other is one of the naturally occurring defective viral genomes (DVG), which can replicate in the presence of WT genome, appears under high MOI passaging conditions and carries a deletion encompassing part of the structural and NS1 protein-coding region. Ordinary differential equations (ODE) were used to simulate the infection of cells by virus particles and intra-cellular replication of the WT and DVG genomes that produces these particles. For each virus passage in Vero and C6/36 cell cultures, rates of the simulated processes were fitted to two types of observations: virus titer data and the assembled haplotypes of the replicate passage samples. We studied the consistency of the model with the experimental data across all passages of infection in each cell type separately, as well as sensitivity of model’s parameters. We also determined which simulated processes of the virus evolution are most important for adaptation of the WT and DVG interplay in these two disparate cell culture environments. Our results demonstrate that in majority of passages, the rates of DVG-production are higher in the C6/36 cells compared to Vero cells, which might result in tolerance and therefore drive persistence of the mosquito vector in the context of ZIKV infection. Additionally, the model simulations showed slower accumulation of infected cells under higher activation of the DVG associated processes, which indicates potential role of DVGs in virus attenuation. Importance. One of ideas on lessening Zika pathogenicity is addition of its natural or engineered defective virus genomes (DVG: have no pathogenicity) to the infection pool: DVG is redirecting the wild type (WT) associated virus development resources to its own maturation. The presented here mathematical model, attuned to the data from interplays between Zika WT viruses and their natural DVG in mammalian and mosquito cells, provides evidence that loss of uninfected cells is attenuated by the DVG development processes. This model enabled us to estimate rates of the virus development processes in the WT/DVG interplay, determine the key processes, and show that the key processes are faster in mosquito cells than in mammalian ones. In general, the presented model and its detailed study suggest in what important virus development processes the therapeutically efficient DVG might compete with WT: this may help in assembling engineered DVGs for ZIKV and other flaviviruses.

scholarly journals Differential inhibition of dengue virus infection in mammalian and mosquito cells by iota-carrageenan

2011 ◽  
Vol 92 (6) ◽  
pp. 1332-1342 ◽  
Author(s):  
Laura B. Talarico ◽  
Miguel D. Noseda ◽  
Diogo R. B. Ducatti ◽  
Maria E. R. Duarte ◽  
Elsa B. Damonte
Keyword(s):  
Dengue Virus ◽  
Mammalian Cells ◽  
Differential Susceptibility ◽  
Cell Types ◽  
Vero Cells ◽  
Yield Reduction ◽  
Structural Class ◽  
Mosquito Cells ◽  
Refractory State ◽  
Pre Treatment

The antiviral activity against dengue virus-2 (DENV-2) of carrageenans reported here has shown a differential susceptibility of C6/36 HT and Vero cells, taken as models of mosquito and mammalian cells, depending on the structural class of polysaccharides: all polysaccharides blocked DENV-2 infection in monkey Vero cells, but only iota-carrageenans were virus inhibitors in mosquito cells. However, iota-carrageenans were less effective in mosquito cells in comparison with mammalian cells with effective concentration 50 % (EC50) values in C6/36 HT cells 4.9–17.5-fold higher than in Vero cells, as determined by virus yield reduction assay. The mode of action of iota-carrageenan in both cell types was strikingly different: in Vero cells the inhibitory activity was exerted only at the initiation of the cycle, affecting virion binding, whereas in mosquito cells DENV-2 adsorption was not affected and comparable levels of inhibition were obtained if the compound was added to cells together with the virus, after 8 h of infection or by cell pre-treatment before infection. Furthermore, iota-carrageenans induced a subtle alteration in mosquito cells, detected by cell proliferation and protein synthesis analyses, suggesting that a probable cellular target may be responsible for the refractory state of mosquito cells to DENV-2 infection produced by this class of polysulfates. The failure of iota-carrageenan to block DENV-2 adsorption to mosquito cells appeared to be related to the low presence of adequate heparan sulfate (HS) in C6/36 HT cell surface and is indicative of a differential participation of HS residues for DENV-2 entry in both types of cells.

scholarly journals Bisbenzylisoquinoline Alkaloids of Cissampelos Sympodialis With in Vitro Antiviral Activity Against Zika Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Poliena Gomes da Silva ◽  
Aventino H. Fonseca ◽  
Malu P. Ribeiro ◽  
Taizia D. Silva ◽  
Cristiane F. F. Grael ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
High Performance ◽  
Antiviral Agents ◽  
Virus Titer ◽  
Vero Cells ◽  
Positive Control ◽  
Bisbenzylisoquinoline Alkaloids ◽  
Bioassay Guided Fractionation

In search of new antiviral compounds against Zika virus we conducted a bioassay-guided fractionation of bisbenzyilisoquinoline alkaloids isolated from Cissampelos sympodialis (Menispermaceae), a medicinal plant species endemic to Brazil. Six subfractions were obtained from a tertiary alkaloidal fraction of the rhizomes (TAFrz) using preparative high-performance liquid chromatography. All the subfractions were tested against Zika virus-infected Vero cells as the cellular model to evaluate cytotoxicity and antiviral effective concentrations. The results showed that three of the six TAFrz subfractions tested were active. The most active ones were the subfraction 6 (that consisted of the alkaloids methylwarifteine and warifteine present as a mixture at a ratio of 8.8:1.2 respectively) and the subfraction 5, that was later identified as warifteine, the major tertiary alkaloid of this species. Warifteine was able to significantly reduce virus titer in Zika virus-infected Vero cells with an IC50 of 2.2 μg/ml and this effect was selective (selectivity index, SI = 68.3). Subfraction 6 had an IC50 = 3.5 μg/ml and was more cytotoxic than pure warifteine, with SI = 6.14. Fraction 5 and fraction 6 were more potent in decreasing the viral titer of Zika virus-infected Vero cells than 6-methylmercaptopurine riboside (IC50 = 24.5 μg/ml and SI = 11.9), a mercaptopurine riboside with ZIKV antiviral activity used as a positive control. Our data demonstrate that alkaloids of the bisbenzylisoquinoline type may be explored as new antiviral agents or as an useful pharmacophore for investigating ZIKV antiviral activity.

scholarly journals Favipiravir Does Not Inhibit Chikungunya Virus Replication in Mosquito Cells and Aedes aegypti Mosquitoes

2021 ◽  
Vol 9 (5) ◽  
pp. 944
Author(s):  
Sofie Jacobs ◽  
Lanjiao Wang ◽  
Ana Lucia Rosales Rosas ◽  
Ria Van Berwaer ◽  
Evelien Vanderlinden ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Aedes Aegypti ◽  
Chikungunya Virus ◽  
Active Form ◽  
Metabolic Activation ◽  
Vero Cells ◽  
Mosquito Vector ◽  
Chikv Infection ◽  
Mosquito Cells

Favipiravir (T-705) is a broad-spectrum antiviral drug that inhibits RNA viruses after intracellular conversion into its active form, T-705 ribofuranosyl 5′-triphosphate. We previously showed that T-705 is able to significantly inhibit the replication of chikungunya virus (CHIKV), an arbovirus transmitted by Aedes mosquitoes, in mammalian cells and in mouse models. In contrast, the effect of T-705 on CHIKV infection and replication in the mosquito vector is unknown. Since the antiviral activity of T-705 has been shown to be cell line-dependent, we studied here its antiviral efficacy in Aedes-derived mosquito cells and in Aedes aegypti mosquitoes. Interestingly, T-705 was devoid of anti-CHIKV activity in mosquito cells, despite being effective against CHIKV in Vero cells. By investigating the metabolic activation profile, we showed that, unlike Vero cells, mosquito cells were not able to convert T-705 into its active form. To explore whether alternative metabolization pathways might exist in vivo, Aedes aegypti mosquitoes were infected with CHIKV and administered T-705 via an artificial blood meal. Virus titrations of whole mosquitoes showed that T-705 was not able to reduce CHIKV infection in mosquitoes. Combined, these in vitro and in vivo data indicate that T-705 lacks antiviral activity in mosquitoes due to inadequate metabolic activation in this animal species.

scholarly journals Cell Type-Dependent RNA Recombination Frequency in the Japanese Encephalitis Virus

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Wei-Wei Chiang ◽  
Ching-Kai Chuang ◽  
Mei Chao ◽  
Wei-June Chen
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Mammalian Cells ◽  
Viral Evolution ◽  
Cell Types ◽  
Encephalitis Virus ◽  
Viral Rna ◽  
Rna Recombination ◽  
Mosquito Cells ◽  
Rna Fragments

Japanese encephalitis virus (JEV) is one of approximately 70 flaviviruses, frequently causing symptoms involving the central nervous system. Mutations of its genomic RNA frequently occur during viral replication, which is believed to be a force contributing to viral evolution. Nevertheless, accumulating evidences show that some JEV strains may have actually arisen from RNA recombination between genetically different populations of the virus. We have demonstrated that RNA recombination in JEV occurs unequally in different cell types. In the present study, viral RNA fragments transfected into as well as viral RNAs synthesized in mosquito cells were shown not to be stable, especially in the early phase of infection possibly via cleavage by exoribonuclease. Such cleaved small RNA fragments may be further degraded through an RNA interference pathway triggered by viral double-stranded RNA during replication in mosquito cells, resulting in a lower frequency of RNA recombination in mosquito cells compared to that which occurs in mammalian cells. In fact, adjustment of viral RNA to an appropriately lower level in mosquito cells prevents overgrowth of the virus and is beneficial for cells to survive the infection. Our findings may also account for the slower evolution of arboviruses as reported previously.

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