{"title":"A high-throughput screening system for SARS-CoV-2 entry inhibition, syncytia formation and cell toxicity.","authors":"Shine Varghese Jancy, Santhik Subhasingh Lupitha, Aneesh Chandrasekharan, Shankara Narayanan Varadarajan, Shijulal Nelson-Sathi, Roshny Prasad, Sara Jones, Sreekumar Easwaran, Pramod Darvin, Aswathy Sivasailam, Thankayyan Retnabai Santhoshkumar","doi":"10.1186/s12575-023-00214-1","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>The entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the host cell is mediated through the binding of the SARS-CoV-2 Spike protein via the receptor binding domain (RBD) to human angiotensin-converting enzyme 2 (hACE2). Identifying compounds that inhibit Spike-ACE2 binding would be a promising and safe antiviral approach against COVID-19.</p><p><strong>Methods: </strong>In this study, we used a BSL-2 compatible replication-competent vesicular stomatitis virus (VSV) expressing Spike protein of SARS-CoV-2 with eGFP reporter system (VSV-eGFP-SARS-CoV-2) in a recombinant permissive cell system for high-throughput screening of viral entry blockers. The SARS-CoV-2 permissive reporter system encompasses cells that stably express hACE2-tagged cerulean and H2B tagged with mCherry, as a marker of nuclear condensation, which also enables imaging of fused cells among infected EGFP positive cells and could provide real-time information on syncytia formation.</p><p><strong>Results: </strong>A limited high-throughput screening identified six natural products that markedly inhibited VSV-eGFP-SARS-CoV-2 with minimum toxicity. Further studies of Spike-S1 binding using the permissive cells showed Scillaren A and 17-Aminodemethoxygeldanamycin could inhibit S1 binding to ACE2 among the six leads. A real-time imaging revealed delayed inhibition of syncytia by Scillaren A, Proscillaridin, Acetoxycycloheximide and complete inhibition by Didemnin B indicating that the assay is a reliable platform for any image-based drug screening.</p><p><strong>Conclusion: </strong>A BSL-2 compatible assay system that is equivalent to the infectious SARS-CoV-2 is a promising tool for high-throughput screening of large compound libraries for viral entry inhibitors against SARS-CoV-2 along with toxicity and effects on syncytia. Studies using clinical isolates of SARS-CoV-2 are warranted to confirm the antiviral potency of the leads and the utility of the screening system.</p>","PeriodicalId":8960,"journal":{"name":"Biological Procedures Online","volume":"25 1","pages":"22"},"PeriodicalIF":3.7000,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10373420/pdf/","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biological Procedures Online","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1186/s12575-023-00214-1","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 1
Abstract
Background: The entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the host cell is mediated through the binding of the SARS-CoV-2 Spike protein via the receptor binding domain (RBD) to human angiotensin-converting enzyme 2 (hACE2). Identifying compounds that inhibit Spike-ACE2 binding would be a promising and safe antiviral approach against COVID-19.
Methods: In this study, we used a BSL-2 compatible replication-competent vesicular stomatitis virus (VSV) expressing Spike protein of SARS-CoV-2 with eGFP reporter system (VSV-eGFP-SARS-CoV-2) in a recombinant permissive cell system for high-throughput screening of viral entry blockers. The SARS-CoV-2 permissive reporter system encompasses cells that stably express hACE2-tagged cerulean and H2B tagged with mCherry, as a marker of nuclear condensation, which also enables imaging of fused cells among infected EGFP positive cells and could provide real-time information on syncytia formation.
Results: A limited high-throughput screening identified six natural products that markedly inhibited VSV-eGFP-SARS-CoV-2 with minimum toxicity. Further studies of Spike-S1 binding using the permissive cells showed Scillaren A and 17-Aminodemethoxygeldanamycin could inhibit S1 binding to ACE2 among the six leads. A real-time imaging revealed delayed inhibition of syncytia by Scillaren A, Proscillaridin, Acetoxycycloheximide and complete inhibition by Didemnin B indicating that the assay is a reliable platform for any image-based drug screening.
Conclusion: A BSL-2 compatible assay system that is equivalent to the infectious SARS-CoV-2 is a promising tool for high-throughput screening of large compound libraries for viral entry inhibitors against SARS-CoV-2 along with toxicity and effects on syncytia. Studies using clinical isolates of SARS-CoV-2 are warranted to confirm the antiviral potency of the leads and the utility of the screening system.
期刊介绍:
iological Procedures Online publishes articles that improve access to techniques and methods in the medical and biological sciences.
We are also interested in short but important research discoveries, such as new animal disease models.
Topics of interest include, but are not limited to:
Reports of new research techniques and applications of existing techniques
Technical analyses of research techniques and published reports
Validity analyses of research methods and approaches to judging the validity of research reports
Application of common research methods
Reviews of existing techniques
Novel/important product information
Biological Procedures Online places emphasis on multidisciplinary approaches that integrate methodologies from medicine, biology, chemistry, imaging, engineering, bioinformatics, computer science, and systems analysis.