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Published on: August 14, 2018
High-throughput split-GFP antiviral screening assay against fusogenic paramyxoviruses
Laura Vandemaele1, Thibault Francken1, Joost Schepers1
1Department of Microbiology, Immunology and Transplantation, Rega Institute, Antiviral Drug & Vaccine Research Group, KU Leuven, Herestraat 49 - box 1043, 3000, Leuven, Belgium.
Abstract:
The paramyxovirus family includes important pathogens such as measles and mumps viruses, as well as emerging pathogens with pandemic potential such as Nipah virus. Despite the threat to public health and the frequent identification of novel paramyxoviruses, no antiviral drugs are currently available. A hallmark of most paramyxoviruses is the induction of cell-cell fusion leading to syncytia formation. To facilitate antiviral drug discovery, we leveraged this trait and established a high-throughput split-green fluorescent protein (GFP) antiviral screening assay suitable for high-content imaging through the quantification of virus-induced GFP+ syncytia. The assay was validated with well-known broad-spectrum antiviral compounds against representative members of five different Paramyxovirinae genera. Using this split-GFP assay, a small-molecule repurposing library of approximately 3000 compounds was screened against recombinant Cedar virus (CedV), a nonpathogenic henipavirus. Two molecules were identified: Cathepsin Inhibitor 1 with henipavirus-specific activity and PF-543 with pan-paramyxovirus activity. Both molecules inhibit viral replication by blocking cell-cell fusion. The split-GFP assay presented here will enable the development of extensive drug discovery initiatives aimed at identifying much-needed pan-henipavirus/paramyxovirus inhibitors.
Insights
Researchers developed a novel screening assay to discover antiviral drugs for paramyxoviruses, identifying two promising compounds that inhibit viral cell-cell fusion and replication. This breakthrough aids in developing treatments for dangerous henipaviruses and other paramyxoviruses.
Area of Science:
- Virology
- Drug Discovery
- Molecular Biology
Background:
- Paramyxoviruses, including measles, mumps, and Nipah viruses, pose significant public health threats.
- No specific antiviral drugs are currently available to treat paramyxovirus infections.
- Paramyxovirus infection is characterized by virus-induced cell-cell fusion, leading to syncytia formation.
Purpose of the Study:
- To develop a high-throughput antiviral screening assay for paramyxoviruses.
- To identify novel small-molecule inhibitors targeting paramyxovirus replication.
- To facilitate the discovery of broad-spectrum antiviral drugs against paramyxoviruses.
Main Methods:
- Established a high-throughput split-green fluorescent protein (GFP) antiviral screening assay.
- Validated the assay using known broad-spectrum antiviral compounds against five Paramyxovirinae genera.
- Screened a library of ~3000 small molecules against recombinant Cedar virus (CedV).
Main Results:
- Identified two compounds: Cathepsin Inhibitor 1 with henipavirus-specific activity and PF-543 with pan-paramyxovirus activity.
- Both identified molecules effectively inhibit viral replication by blocking cell-cell fusion.
- The split-GFP assay demonstrated efficacy in identifying inhibitors against different paramyxovirus genera.
Conclusions:
- The developed split-GFP assay is a valuable tool for antiviral drug discovery against paramyxoviruses.
- The identified compounds show potential for treating henipavirus and broader paramyxovirus infections.
- This assay will accelerate the development of much-needed pan-henipavirus/paramyxovirus inhibitors.
