scholarly journals Potential High-Throughput Assay for Screening Inhibitors of West Nile Virus Replication

2003 ◽  
Vol 77 (23) ◽  
pp. 12901-12906 ◽  
Author(s):  
Michael K. Lo ◽  
Mark Tilgner ◽  
Pei-Yong Shi
Keyword(s):  
West Nile Virus ◽  
Cell Line ◽  
High Throughput ◽  
High Throughput Screening ◽  
Health Priorities ◽  
Stable Cell Line ◽  
West Nile ◽  
Subgenomic Replicon ◽  
Genes Encoding ◽  
High Throughput Assay

ABSTRACT Prevention and treatment of infection by West Nile virus (WNV) and other flaviviruses are public health priorities. We describe a reporting cell line that can be used for high-throughput screening of inhibitors against all targets involved in WNV replication. Dual reporter genes, encoding Renilla luciferase (Rluc) and neomycin phosphotransferase (Neo), were engineered into a WNV subgenomic replicon, resulting in Rluc/NeoRep. Geneticin selection of BHK-21 cells transfected with Rluc/NeoRep yielded a stable cell line that contains persistently replicating replicons. Incubation of the reporting cells with known WNV inhibitors decreased Rluc activity, as well as the replicon RNA level. The efficacies of the inhibitors, as measured by the depression of Rluc activity in the reporting cells, are comparable to those derived from authentic viral infection assays. Therefore, the WNV reporting cell line can be used as a high-throughput assay for anti-WNV drug discovery. A similar approach should be applicable to development of genetics-based antiviral assays for other flaviviruses.

scholarly journals High-Throughput Assays Using a Luciferase-Expressing Replicon, Virus-Like Particles, and Full-Length Virus for West Nile Virus Drug Discovery

2005 ◽  
Vol 49 (12) ◽  
pp. 4980-4988 ◽  
Author(s):  
Francesc Puig-Basagoiti ◽  
Tia S. Deas ◽  
Ping Ren ◽  
Mark Tilgner ◽  
David M. Ferguson ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Drug Discovery ◽  
High Throughput ◽  
Viral Entry ◽  
High Throughput Screening ◽  
Full Length ◽  
West Nile ◽  
Subgenomic Replicon ◽  
Virion Assembly ◽  
Virus Like Particles

ABSTRACT Many flaviviruses cause significant human disease worldwide. The development of flavivirus chemotherapy requires reliable high-throughput screening (HTS) assays. Although genetic systems have been developed for many flaviviruses, their usage in antiviral HTS assays has not been well explored. Here we compare three cell-based HTS assays for West Nile virus (WNV) drug discovery: (i) an assay that uses a cell line harboring a persistently replicating subgenomic replicon (containing a deletion of viral structural genes), (ii) an assay that uses packaged virus-like particles containing replicon RNA, and (iii) an assay that uses a full-length reporting virus. A Renilla luciferase gene was engineered into the replicon or into the full-length viral genome to monitor viral replication. Potential inhibitors could be identified through suppression of luciferase signals upon compound incubation. The antiviral assays were optimized in a 96-well format, validated with known WNV inhibitors, and proved useful in identifying a new inhibitor(s) through HTS of a compound library. In addition, because each assay encompasses multiple but discrete steps of the viral life cycle, the three systems could potentially be used to discriminate the mode of action of any inhibitor among viral entry (detected by assays ii and iii but not by assay i), replication (including viral translation and RNA synthesis; detected by assays i to iii), and virion assembly (detected by assay iii but not by assays i and ii). The approaches described in this study should be applicable to the development of cell-based assays for other flaviviruses.

scholarly journals Identification of Novel Human High-Density Lipoprotein Receptor Up-regulators Using a Cell-Based High-Throughput Screening Assay

2007 ◽  
Vol 12 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Yuan Yang ◽  
Zhongbing Zhang ◽  
Wei Jiang ◽  
Lei Gao ◽  
Guiyu Zhao ◽  
...  
Keyword(s):  
High Density Lipoprotein ◽  
Cell Line ◽  
High Throughput ◽  
Hepg2 Cells ◽  
High Throughput Screening ◽  
Density Lipoprotein ◽  
High Density ◽  
Luciferase Reporter ◽  
Stable Cell Line ◽  
Active Compounds

Scavenger receptor class B type I (SR-BI) is the high-affinity high-density lipoprotein (HDL) receptor, and CLA-1 is the human homologue of the murine SR-BI. CLA-1/SR-BI receptor has been suggested as a new preventative and/or therapeutic target for atherosclerosis due to its pivotal role in overall HDL cholesterol (HDL-C) metabolism and its antiatherogenic activity in vivo. To search for active compounds that can increase CLA-1 transcription, a novel cell-based assay was developed for application in high-throughput screening (HTS). Human hepatoma HepG2 cells were transfected with a CLA-1-promoter-luciferase reporter gene construct, and the stable transfected cell line was selected and named CLAp-LUC HepG2. With rosiglitazone as a positive control, this stable cell line was used to establish a specific CLA-1 gene expression assay in a 96-well microplate format. The evaluating parameter Z' value of 0.64 showed that this cell-based HTS assay was robust and reliable. Screening of 6000 microbial secondary metabolite crude extracts identified 8 positive strains. Between 2 identified CLA-1 up-regulators produced by actinomycete strain 04-4776, 4776B may stimulate not only the expression of CLA-1 on the transcriptional and translational levels but also the activity of CLA-1 to uptake the HDL-C in HepG2 cells. The active compounds originated from this HTS assay may be developed to drug candidates or lead compounds for new antiatherosclerosis agents.

scholarly journals Establishment of a stable SARS-CoV-2 replicon system for application in high-throughput screening.

2021 ◽  
Author(s):  
Tomohisa Tanaka ◽  
Akatsuki Saito ◽  
Tatsuya Suzuki ◽  
Yoichi Miyamoto ◽  
Kazuo Takayama ◽  
...  
Keyword(s):  
Viral Replication ◽  
Cell Line ◽  
High Throughput ◽  
High Throughput Screening ◽  
Luciferase Activity ◽  
Fusion Gene ◽  
Viral Proteins ◽  
Renilla Luciferase ◽  
Interferon Β ◽  
Subgenomic Replicon

Experiments with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited by the need for biosafety level 3 (BSL3) conditions. A SARS-CoV-2 replicon system rather than an in vitro infection system is suitable for antiviral screening since it can be handled under BSL2 conditions and does not produce infectious particles. However, the reported replicon systems are cumbersome because of the need for transient transfection in each assay. In this study, we constructed a bacterial artificial chromosome vector (the replicon-BAC vector) including the SARS-CoV-2 replicon and a fusion gene encoding Renilla luciferase and neomycin phosphotransferase II, examined the antiviral effects of several known compounds, and then established a cell line stably harboring the replicon-BAC vector. Several cell lines transiently transfected with the replicon-BAC vector produced subgenomic replicon RNAs (sgRNAs) and viral proteins, and exhibited luciferase activity. In the transient replicon system, treatment with remdesivir or interferon-β but not with camostat or favipiravir suppressed the production of viral agents and luciferase, indicating that luciferase activity corresponds to viral replication. VeroE6/Rep3, a stable replicon cell line based on VeroE6 cells, was successfully established and continuously produced viral proteins, sgRNAs and luciferase, and their production was suppressed by treatment with remdesivir or interferon-β. Molnupiravir, a novel coronavirus RdRp inhibitor, inhibited viral replication more potently in VeroE6/Rep3 cells than in VeroE6-based transient replicon cells. In summary, our stable replicon system will be a powerful tool for the identification of SARS-CoV-2 antivirals through high-throughput screening.

scholarly journals Identification of Novel Small-Molecule Inhibitors of West Nile Virus Infection

2007 ◽  
Vol 81 (21) ◽  
pp. 11992-12004 ◽  
Author(s):  
Amine O. Noueiry ◽  
Paul D. Olivo ◽  
Urszula Slomczynska ◽  
Yi Zhou ◽  
Ben Buscher ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Yellow Fever ◽  
High Throughput Screening ◽  
Yellow Fever Virus ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chemical Library ◽  
Entry Site ◽  
West Nile ◽  
Subgenomic Replicon

ABSTRACT West Nile virus (WNV) has spread throughout the United States and Canada and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to acute flaccid paralysis and lethal encephalitis. No therapy or vaccine is currently approved for use in humans. Using high-throughput screening assays that included a luciferase expressing WNV subgenomic replicon and an NS1 capture enzyme-linked immunosorbent assay, we evaluated a chemical library of over 80,000 compounds for their capacity to inhibit WNV replication. We identified 10 compounds with strong inhibitory activity against genetically diverse WNV and Kunjin virus isolates. Many of the inhibitory compounds belonged to a chemical family of secondary sulfonamides and have not been described previously to inhibit WNV or other related or unrelated viruses. Several of these compounds inhibited WNV infection in the submicromolar range, had selectivity indices of greater than 10, and inhibited replication of other flaviviruses, including dengue and yellow fever viruses. One of the most promising compounds, AP30451, specifically blocked translation of a yellow fever virus replicon but not a Sindbis virus replicon or an internal ribosome entry site containing mRNA. Overall, these compounds comprise a novel class of promising inhibitors for therapy against WNV and other flavivirus infections in humans.

scholarly journals Inducible APOBEC3G-Vif Double Stable Cell Line as a High-Throughput Screening Platform To Identify Antiviral Compounds

2009 ◽  
Vol 54 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Boris Nowotny ◽  
Thomas Schneider ◽  
Gabriele Pradel ◽  
Tanja Schirmeister ◽  
Axel Rethwilm ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Cell Line ◽  
High Throughput ◽  
High Throughput Screening ◽  
Yellow Fluorescent Protein ◽  
26S Proteasome ◽  
Stable Cell Line ◽  
Antiviral Compound ◽  
Compound Libraries ◽  
Antiviral Compounds

ABSTRACT Inhibition of the interaction of the human cytidine-deaminase APOBEC3G (A3G) with the human immunodeficiency virus (HIV) type 1-specific viral infectivity factor (Vif) represents a novel therapeutic approach in which a cellular factor with potent antiviral activity (A3G) plays a key role. In HIV-infected cells, the interaction of Vif with A3G leads to the subsequent degradation of A3G by the 26S proteasome via the ubiquitin pathway and to the loss of antiviral activity. To establish a stable and convenient cellular testing platform for the high-throughput screening of potential antiviral compound libraries, we engineered a double transgenic cell line constitutively expressing an enhanced yellow fluorescent protein expressor (EYFP-A3G) fusion as well as a Tet-Off controllable Vif protein. With this cell line, we were able to measure precisely the Vif-induced degradation of A3G in the presence of potential antiviral compounds in an easy-to-handle, robust, and practical high-throughput multiwell plate format with an excellent screening window coefficient (Z factor) of 0.67.

scholarly journals Development of a Multivalent Kunjin Virus Reporter Virus-Like Particle System Inducing Seroconversion for Ebola and West Nile Virus Proteins in Mice

2020 ◽  
Vol 8 (12) ◽  
pp. 1890
Author(s):  
Pham-Tue-Hung Tran ◽  
Naveed Asghar ◽  
Urban Höglund ◽  
Olivia Larsson ◽  
Lars Haag ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Cell Line ◽  
Matrix Protein ◽  
Particle System ◽  
Nonstructural Protein ◽  
Stable Cell Line ◽  
Reporter Virus ◽  
Structural Genes ◽  
West Nile ◽  
Nonstructural Protein 1

Kunjin virus (KUNV) is an attenuated strain of the severe neurotropic West Nile virus (WNV). The virus has a single-strand positive-sense RNA genome that encodes a polyprotein. Following gene expression, the polyprotein is cleaved into structural proteins for viral packaging and nonstructural proteins for viral replication and expression. Removal of the structural genes generate subgenomic replicons that maintain replication capacity. Co-expression of these replicons with the viral structural genes produces reporter virus-like particles (RVPs) which infect cells in a single round. In this study, we aimed to develop a system to generate multivalent RVPs based on KUNV to elicit an immune response against different viruses. We selected the Ebola virus (EBOV) glycoprotein (GP) and the matrix protein (VP40) genes, as candidates to be delivered by KUNV RVPs. Initially, we enhanced the production of KUNV RVPs by generating a stable cell line expressing the KUNV packaging system comprising capsid, precursor membrane, and envelope. Transfection of the DNA-based KUNV replicon into this cell line resulted in an enhanced RVP production. The replicon was expressed in the stable cell line to produce the RVPs that allowed the delivery of EBOV GP and VP40 genes into other cells. Finally, we immunized BALB/cN mice with RVPs, resulting in seroconversion for EBOV GP, EBOV VP40, WNV nonstructural protein 1, and WNV E protein. Thus, our study shows that KUNV RVPs may function as a WNV vaccine candidate and RVPs can be used as a gene delivery system in the development of future EBOV vaccines.

scholarly journals Nasal Immunization With Small Molecule Mast Cell Activators Enhance Immunity to Co-Administered Subunit Immunogens

2021 ◽  
Vol 12 ◽  
Author(s):  
Brandi T. Johnson-Weaver ◽  
Hae Woong Choi ◽  
Hang Yang ◽  
Josh A. Granek ◽  
Cliburn Chan ◽  
...  
Keyword(s):  
Mast Cell ◽  
West Nile Virus ◽  
Small Molecule ◽  
High Throughput ◽  
High Throughput Screening ◽  
Mucosal Vaccine ◽  
Vaccine Adjuvants ◽  
West Nile ◽  
Adjuvant Activity ◽  
Nasal Vaccine

Mast cell activators are a novel class of mucosal vaccine adjuvants. The polymeric compound, Compound 48/80 (C48/80), and cationic peptide, Mastoparan 7 (M7) are mast cell activators that provide adjuvant activity when administered by the nasal route. However, small molecule mast cell activators may be a more cost-efficient adjuvant alternative that is easily synthesized with high purity compared to M7 or C48/80. To identify novel mast cell activating compounds that could be evaluated for mucosal vaccine adjuvant activity, we employed high-throughput screening to assess over 55,000 small molecules for mast cell degranulation activity. Fifteen mast cell activating compounds were down-selected to five compounds based on in vitro immune activation activities including cytokine production and cellular cytotoxicity, synthesis feasibility, and selection for functional diversity. These small molecule mast cell activators were evaluated for in vivo adjuvant activity and induction of protective immunity against West Nile Virus infection in BALB/c mice when combined with West Nile Virus envelope domain III (EDIII) protein in a nasal vaccine. We found that three of the five mast cell activators, ST101036, ST048871, and R529877, evoked high levels of EDIII-specific antibody and conferred comparable levels of protection against WNV challenge. The level of protection provided by these small molecule mast cell activators was comparable to the protection evoked by M7 (67%) but markedly higher than the levels seen with mice immunized with EDIII alone (no adjuvant 33%). Thus, novel small molecule mast cell activators identified by high throughput screening are as efficacious as previously described mast cell activators when used as nasal vaccine adjuvants and represent next-generation mast cell activators for evaluation in mucosal vaccine studies.

scholarly journals Identification of a juvenile-hormone signaling inhibitor via high-throughput screening of a chemical library

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Takumi Kayukawa ◽  
Kenjiro Furuta ◽  
Keisuke Nagamine ◽  
Tetsuro Shinoda ◽  
Kiyoaki Yonesu ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Cell Line ◽  
Signaling Pathway ◽  
High Throughput ◽  
High Throughput Screening ◽  
Large Scale ◽  
Ex Vivo ◽  
Agricultural Field ◽  
Chemical Library ◽  
Field Development

Abstract Insecticide resistance has recently become a serious problem in the agricultural field. Development of insecticides with new mechanisms of action is essential to overcome this limitation. Juvenile hormone (JH) is an insect-specific hormone that plays key roles in maintaining the larval stage of insects. Hence, JH signaling pathway is considered a suitable target in the development of novel insecticides; however, only a few JH signaling inhibitors (JHSIs) have been reported, and no practical JHSIs have been developed. Here, we established a high-throughput screening (HTS) system for exploration of novel JHSIs using a Bombyx mori cell line (BmN_JF&AR cells) and carried out a large-scale screening in this cell line using a chemical library. The four-step HTS yielded 69 compounds as candidate JHSIs. Topical application of JHSI48 to B. mori larvae caused precocious metamorphosis. In ex vivo culture of the epidermis, JHSI48 suppressed the expression of the Krüppel homolog 1 gene, which is directly activated by JH-liganded receptor. Moreover, JHSI48 caused a parallel rightward shift in the JH response curve, suggesting that JHSI48 possesses a competitive antagonist-like activity. Thus, large-scale HTS using chemical libraries may have applications in development of future insecticides targeting the JH signaling pathway.

scholarly journals Development of a High-Throughput Screening Assay to Identify Inhibitors of the SARS-CoV-2 Guanine-N7-Methyltransferase Using RapidFire Mass Spectrometry

2021 ◽  
pp. 247255522110006
Author(s):  
Lesley-Anne Pearson ◽  
Charlotte J. Green ◽  
De Lin ◽  
Alain-Pierre Petit ◽  
David W. Gray ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Mutational Analysis ◽  
Nonstructural Protein ◽  
Translation Efficiency ◽  
Screening Assay ◽  
High Throughput Screening Assay ◽  
Starting Point ◽  
Approved Drugs ◽  
High Throughput Assay

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a significant threat to human health. Despite its similarity to related coronaviruses, there are currently no specific treatments for COVID-19 infection, and therefore there is an urgent need to develop therapies for this and future coronavirus outbreaks. Formation of the cap at the 5′ end of viral RNA has been shown to help coronaviruses evade host defenses. Nonstructural protein 14 (nsp14) is responsible for N7-methylation of the cap guanosine in coronaviruses. This enzyme is highly conserved among coronaviruses and is a bifunctional protein with both N7-methyltransferase and 3′-5′ exonuclease activities that distinguish nsp14 from its human equivalent. Mutational analysis of SARS-CoV nsp14 highlighted its role in viral replication and translation efficiency of the viral genome. In this paper, we describe the characterization and development of a high-throughput assay for nsp14 utilizing RapidFire technology. The assay has been used to screen a library of 1771 Food and Drug Administration (FDA)-approved drugs. From this, we have validated nitazoxanide as a selective inhibitor of the methyltransferase activity of nsp14. Although modestly active, this compound could serve as a starting point for further optimization.

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