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Updated: Dec 26, 2025
High-throughput Screening for Broad-spectrum Chemical Inhibitors of RNA Viruses
Published on: May 5, 2014
Combined siRNA and Small-Molecule Phenotypic Screening Identifies Targets Regulating Rhinovirus Replication in
Mei Ding1, Christian Tyrchan2, Elisabeth Bäck1
1Discovery Sciences, Research and Early Development, R&D BioPharmaceuticals, AstraZeneca, Gothenburg, Sweden.
Abstract:
Human rhinovirus (RV) is the most common cause of acute upper respiratory tract infections and has recently been shown to play a significant role in exacerbations of asthma and chronic obstructive pulmonary disease (COPD). There is a significant unmet medical need for agents for the prevention and/or treatment of exacerbations triggered by human RV infection. Phenotypic drug discovery programs using different perturbation modalities, for example, siRNA, small-molecule compounds, and CRISPR, hold significant value for identifying novel drug targets. We have previously reported the identification of lanosterol synthase as a novel regulator of RV2 replication through a phenotypic screen of a library of siRNAs against druggable genes in normal human bronchial epithelial (NHBE) cells. Here, we describe a follow-up phenotypic screen of small-molecule compounds that are annotated to be pharmacological regulators of target genes that were identified to significantly affect RV2 replication in the siRNA primary screen of 10,500 druggable genes. Two hundred seventy small-molecule compounds selected for interacting with 122 target gene hits were screened in the primary RV2 assay in NHBE cells by quantifying viral replication via in situ hybridization followed by secondary quantitative PCR-based assays for RV2, RV14, and RV16. The described follow-up phenotypic screening allowed us to identify Fms-related tyrosine kinase 4 (FLT4) as a novel target regulating RV replication. We demonstrate that a combination of siRNA and small-molecule compound screening models is a useful phenotypic drug discovery approach for the identification of novel drug targets.
Insights
Human rhinovirus (RV) causes respiratory infections and asthma exacerbations. Researchers identified Fms-related tyrosine kinase 4 (FLT4) as a novel target for RV replication, offering new therapeutic avenues.
Area of Science:
- Virology
- Drug Discovery
- Respiratory Medicine
Background:
- Human rhinovirus (RV) is a common cause of respiratory infections and exacerbations of asthma and COPD.
- There is a critical need for new treatments to prevent or manage RV-induced exacerbations.
Purpose of the Study:
- To identify novel drug targets for human rhinovirus (RV) replication using phenotypic screening.
- To validate a combined siRNA and small-molecule compound screening approach for drug discovery.
Main Methods:
- Phenotypic screening of siRNAs against druggable genes to identify RV2 replication regulators.
- Follow-up screening of small-molecule compounds targeting genes identified in the siRNA screen.
- Quantification of viral replication using in situ hybridization and quantitative PCR for RV strains.
Main Results:
- Lanosterol synthase was previously identified as a regulator of RV2 replication.
- Fms-related tyrosine kinase 4 (FLT4) was identified as a novel target regulating RV replication.
- The combined screening approach proved effective in identifying new drug targets.
Conclusions:
- Combined siRNA and small-molecule phenotypic screening is a valuable approach for identifying novel drug targets.
- FLT4 represents a potential new target for therapeutic intervention against human rhinovirus infections.
