shRNA targeting nonstructural protein inhibits the replication of severe fever with thrombocytopenia syndrome virus

2021 ◽  
Author(s):  
Lili Dou ◽  
Xiaoli Tao ◽  
Wei Zhao ◽  
Guofeng Zheng ◽  
Ying Lu ◽  
...  

Aim: To explore whether shRNA targeting nonstructural protein (NSs) of severe fever with thrombocytopenia syndrome virus (SFTSV) could inhibit SFTSV replication in Vero cells. Materials & methods: SFTSV used in this experiment was propagated in Vero cells and stored at -20°C. shRNA plasmid against NSs of SFTSV was transfected to Vero cells and infected with SFTSV, after which western blotting and tissue culture infective dose (TCID50) were used to measure the virus titers. Results: shRNA against NSs protein decreased the expression of NSs and inhibited the replication of SFTSV. Conclusion: The constructed SFTSV NSs-shRNA plasmid could inhibit the replication of SFTSV. It was concluded that SFTSV NSs-shRNA could inhibit virus replication for at least 72 h. shRNA-mediated antiviral effects were dose-dependent.

2021 ◽  
Vol 12 ◽  
Author(s):  
Changchao Huan ◽  
Weiyin Xu ◽  
Bo Ni ◽  
Tingting Guo ◽  
Haochun Pan ◽  
...  

There are currently no licensed drugs against porcine epidemic diarrhea virus (PEDV), but vaccines are available. We identified a natural molecule, epigallocatechin-3-gallate (EGCG), the main polyphenol in green tea, which is effective against infection with PEDV. We used a variety of methods to test its effects on PEDV in Vero cells. Our experiments show that EGCG can effectively inhibit PEDV infections (with HLJBY and CV777 strains) at different time points in the infection using western blot analysis. We found that EGCG inhibited PEDV infection in a dose-dependent manner 24 h after the infection commenced using western blotting, plaque formation assays, immunofluorescence assays (IFAs), and quantitative reverse-transcriptase PCR (qRT-PCR). We discovered that EGCG treatment of Vero cells decreased PEDV attachment and entry into them by the same method analysis. Western blotting also showed that PEDV replication was inhibited by EGCG treatment. Whereas EGCG treatment was found to inhibit PEDV assembly, it had no effect on PEDV release. In summary, EGCG acts against PEDV infection by inhibiting PEDV attachment, entry, replication, and assembly.


2018 ◽  
Vol 32 (12) ◽  
pp. 6706-6723 ◽  
Author(s):  
Huisheng Liu ◽  
Qiao Xue ◽  
Weijun Cao ◽  
Fan Yang ◽  
Linna Ma ◽  
...  

2015 ◽  
Vol 89 (14) ◽  
pp. 7170-7186 ◽  
Author(s):  
Laurent Chatel-Chaix ◽  
Wolfgang Fischl ◽  
Pietro Scaturro ◽  
Mirko Cortese ◽  
Stephanie Kallis ◽  
...  

ABSTRACTDengue virus (DENV) infection causes the most prevalent arthropod-borne viral disease worldwide. Approved vaccines are not available, and targets suitable for the development of antiviral drugs are lacking. One possible drug target is nonstructural protein 4B (NS4B), because it is absolutely required for virus replication; however, its exact role in the DENV replication cycle is largely unknown. With the aim of mapping NS4B determinants critical for DENV replication, we performed a reverse genetic screening of 33 NS4B mutants in the context of an infectious DENV genome. While the majority of these mutations were lethal, for several of them, we were able to select for second-site pseudoreversions, most often residing in NS4B and restoring replication competence. To identify all viral NS4B interaction partners, we engineered a fully viable DENV genome encoding an affinity-tagged NS4B. Mass spectrometry-based analysis of the NS4B complex isolated from infected cells identified the NS3 protease/helicase as a major interaction partner of NS4B. By combining the genetic complementation map of NS4B with a replication-independent expression system, we identified the NS4B cytosolic loop—more precisely, amino acid residue Q134—as a critical determinant for NS4B-NS3 interaction. An alanine substitution at this site completely abrogated the interaction and DENV RNA replication, and both were restored by pseudoreversions A69S and A137V. This strict correlation between the degree of NS4B-NS3 interaction and DENV replication provides strong evidence that this viral protein complex plays a pivotal role during the DENV replication cycle, hence representing a promising target for novel antiviral strategies.IMPORTANCEWith no approved therapy or vaccine against dengue virus infection, the viral nonstructural protein 4B (NS4B) represents a possible drug target, because it is indispensable for virus replication. However, little is known about its precise structure and function. Here, we established the first comprehensive genetic interaction map of NS4B, identifying amino acid residues that are essential for virus replication, as well as second-site mutations compensating for their defects. Additionally, we determined the NS4B viral interactome in infected cells and identified the NS3 protease/helicase as a major interaction partner of NS4B. We mapped residues in the cytosolic loop of NS4B as critical determinants for interaction with NS3, as well as RNA replication. The strong correlation between NS3-NS4B interaction and RNA replication provides strong evidence that this complex plays a pivotal role in the viral replication cycle, hence representing a promising antiviral drug target.


2012 ◽  
Vol 86 (12) ◽  
pp. 6491-6502 ◽  
Author(s):  
I. Nevo-Yassaf ◽  
Y. Yaffe ◽  
M. Asher ◽  
O. Ravid ◽  
S. Eizenberg ◽  
...  

2018 ◽  
Vol 51 (3) ◽  
pp. 1250-1263 ◽  
Author(s):  
Fengying Sun ◽  
Ying Ni ◽  
Hong Zhu ◽  
Jian Fang ◽  
Hua Wang ◽  
...  

Background/Aims: Helicobacter pylori (H. pylori) infection is closely related to human gastric mucosa-associated diseases. Several recent studies on miRNAs have expanded our insights on H.pylori pathogenesis. This study aimed to investigate the biological roles and underlying molecular mechanisms of miR-29a-3p in human gastric cells and tissues with H.pylori infection. Methods: miR-29a-3p expression was quantified by quantitative RT-PCR (qRT-PCR). A miR-29a-3p target gene was validated by bioinformatics analysis, western blotting and dual luciferase reporter gene assays. Western blotting and immunohistochemistry (IHC) assay were performed to detect the protein expression. Transwell assay was used to determine the cell migration ability. Results: MiR-29a-3p was up-regulated in H.pylori-positive gastric mucosa tissues and H.pylori-infected gastric cells. The up-regulation of miR-29a-3p was dose-dependent in BGC-823 and GES-1 cells infected with H.pylori. Using gain- and loss-of-function experiments in vitro, we demonstrated that miR-29a-3p promoted the migration of gastric epithelial cells. We further characterized A20 as a direct target of miR-29a-3p. The expression of A20 was decreased in H.pylori-positive gastric mucosa tissues compared with H.pylori-negative gastric mucosa tissues. A20 downregulation was time- and dose-dependent in GES-1 and BGC-823 cells infected with H.pylori. In GES-1 and BGC-823 cells infected with H.pylori, the miR-29a-3p mimic significantly blocked A20 expression, which suggests that H.pylori decreased A20 expression through up-regulating miR-29a-3p in GES-1 and BGC-823 cells infected with H.pylori. The knockdown of A20 by siRNA enhanced the migration of human gastric epithelial cells and promoted the expression of Snail, Vimentin, and N-cadherin and inhibited the expression of E-cadherin. Conclusion: The miR-29a-3p may act as a tumor promotive miRNA by regulating cells migration through directly targeting of A20 gene in human gastric epithelial cells infected with H.pylori.


2020 ◽  
Author(s):  
Saisai Wang ◽  
Yiting Ling ◽  
Yuanyuan Yao ◽  
Gang Zheng ◽  
Wenbin Chen

Abstract Background: Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants, children, immunocompromised adults, and elderly individuals. Currently, there are few therapeutic options available to prevent RSV infection. The present study aimed to investigate the effects of luteolin on RSV replication and the related mechanisms. Material and methods: We pretreated cells and mice with luteolin before infection with RSV, the virus titer, expressions of RSV-F, interferon (IFN)-stimulated genes (ISGs), and production of IFN-α and IFN-β were determined by plaque assay, RT-qPCR, and ELISA, respectively. The activation of Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1) signaling pathway was detected by Western blotting and luciferase assay. Proteins which negatively regulates STAT1 was determined by Western blotting. Then cells were transfected with suppressor of cytokine signaling 1 (SOCS1) plasmid and virus replication and ISGs expression was determined. Luciferase reporter assay and Western blotting was performed to detect the relationship between SOCS1 and miR-155. Results: Luteolin inhibited RSV replication, as shown by the decreased viral titer and RSV-F mRNA expression both in vitro and in vivo. The antiviral activity of luteolin was attributed to the enhanced phosphorylation of STAT1, resulting in the increased production of ISGs. Further study showed that SOCS1 was downregulated by luteolin and SOCS1 is a direct target of microRNA-155 (miR-155). Inhibition of miR-155 rescued luteolin-mediated SOCS1 downregulation, whereas upregulation of miR-155 enhanced the inhibitory effect of luteolin. Conclusion: Luteolin inhibits RSV replication by regulating the miR-155/SOCS1/STAT1 signaling pathway.


2014 ◽  
Vol 89 (1) ◽  
pp. 337-349 ◽  
Author(s):  
David J. Morales ◽  
Kristen Monte ◽  
Lulu Sun ◽  
Jessica J. Struckhoff ◽  
Eugene Agapov ◽  
...  

ABSTRACTISG15 is a diubiquitin-like modifier and one of the most rapidly induced genes upon type I interferon stimulation. Hundreds of host proteins and a number of viral proteins have been shown to be ISGylated, and understanding how these modifications affect the interferon response and virus replication has been of considerable interest. ISG15−/−mice exhibit increased susceptibility to viral infection, and in the case of influenza B virus and vaccinia virus, ISG15 conjugation has been shown to restrict virus replicationin vivo. A number of studies have also found that ISG15 is capable of antagonizing replication of some viruses in tissue culture. However, recent findings have demonstrated that ISG15 can protect mice from Chikungunya virus infection without affecting the virus burden. In order to better understand the function of ISG15in vivo, we characterized the pathogenesis of influenza A virus and Sendai virus in ISG15−/−mice. We found that ISG15 protects mice from virus induced lethality by a conjugation-dependent mechanism in both of these models. However, surprisingly, we found that ISG15 had minimal effect on virus replication and did not have an obvious role in the modulation of the acute immune response to infection. Instead, we observed an increase in the number of diseased small airways in mice lacking ISG15. This ability of ISG15 to protect mice in a conjugation-dependent, but nonantiviral, manner from respiratory virus infection represents a previously undescribed role for ISG15 and demonstrates the importance of further characterization of ISG15in vivo.IMPORTANCEIt has previously been demonstrated that ISG15−/−mice are more susceptible to a number of viral infections. Since ISG15 is one of the most strongly induced genes after type I interferon stimulation, analysis of ISG15 function has largely focused on its role as an antiviral molecule during acute infection. Although a number of studies have shown that ISG15 does have a small effect on virus replication in tissue culture, few studies have confirmed this mechanism of protectionin vivo. In these studies we have found that while ISG15−/−mice are more susceptible to influenza A virus and Sendai virus infections, ISGylation does not appear to mediate this protection through the direct inhibition of virus replication or the modulation of the acute immune response. Thus, in addition to showing a novel mode of ISG15 mediated protection from virus infection, this study demonstrates the importance of studying the role of ISG15in vivo.


2008 ◽  
Vol 27 (4) ◽  
pp. 341-346 ◽  
Author(s):  
EA Soria ◽  
ME Goleniowski ◽  
JJ Cantero ◽  
GA Bongiovanni

Chronic toxicity of arsenic resulting from drinking water is a health problem encountered in humans, especially in South America and Asia, where a correlation between oxidative stress, tumor promotion, and arsenic exposure has been observed. Differential solvent extraction (petroleum ether (PE); dichloromethane (DCM); methanol (OL) and water (W)) was performed to compare the protective (antioxidant) activity of five Argentinian medicinal plants on arsenite-induced oxidative stress in Vero cells, assayed by hydroperoxide measurement. The results were analyzed using ANOVA followed by the LSD Fisher test. The data showed that arsenite was a pro-oxidant agent which acts in a time–dose-dependent manner. Extracts from Eupatorium buniifolium (PE), Lantana grisebachii (PE, W), Mandevilla pentlandiana (PE, W), and Sebastiania commersoniana (DCM, OL, W) prevented the formation of both aqueous and lipid hydroperoxides, but Heterothalamus alienus only impeded lipid ones. Therefore, antioxidant extracts are potentially beneficial and may have a protective activity against arsenite-induced renal injury. Among these, the aqueous extract of L. grisebachii may represent the most suitable preparation for humans since the traditional usage of this plant in popular medicine is through consumption of tea.


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