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Updated: Jul 9, 2025
Dissecting Innate Immune Signaling in Viral Evasion of Cytokine Production
Published on: March 2, 2014
Enterovirus D68 vRNA induces type III IFN production via MDA5
Chi-Chong Chio1, Hio-Wai Chan2, Shih-Hsiang Chen3
1Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan, Taiwan.
Abstract:
Enterovirus D68 (EV-D68) primarily spreads through the respiratory tract and causes respiratory symptoms in children and acute flaccid myelitis (AFM). Type III interferons (IFNs) play a critical role in inhibiting viral growth in respiratory epithelial cells. However, the mechanism by which EV-D68 induces type III IFN production is not yet fully understood. In this study, we show that EV-D68 infection stimulates Calu-3 cells to secrete IFN-λ. The transfection of EV-D68 viral RNA (vRNA) stimulated IFN-λ via MDA5. Furthermore, our findings provide evidence that EV-D68 infection also induces MDA5-IRF3/IRF7-mediated IFN-λ. In addition, we discovered that EV-D68 infection downregulated MDA5 expression. Knockdown of MDA5 increased EV-D68 replication in Calu-3 cells. Finally, we demonstrated that the IFN-λ1 and IFN-λ2/3 proteins effectively inhibit EV-D68 infection in respiratory epithelial cells. In summary, our study shows that EV-D68 induces type III IFN production via the activated MDA5-IRF3/IRF7 pathway and that type III IFNs inhibit EV-D68 replication in Calu-3 cells.
Insights
Enterovirus D68 (EV-D68) triggers type III interferon (IFN) production through the MDA5-IRF3/IRF7 pathway in respiratory cells. These type III IFNs effectively inhibit EV-D68 viral replication, offering insights into antiviral defense mechanisms.
Area of Science:
- Virology
- Immunology
- Respiratory Medicine
Background:
- Enterovirus D68 (EV-D68) is a respiratory virus causing significant illness in children, including acute flaccid myelitis (AFM).
- Type III interferons (IFNs) are crucial for antiviral defense in respiratory epithelial cells, but the induction mechanism by EV-D68 remains unclear.
Purpose of the Study:
- To elucidate the mechanism by which EV-D68 infection induces type III IFN production.
- To investigate the role of MDA5 and downstream signaling pathways in this response.
- To assess the antiviral efficacy of type III IFNs against EV-D68.
Main Methods:
- EV-D68 infection and viral RNA (vRNA) transfection in Calu-3 respiratory epithelial cells.
- Analysis of IFN-λ secretion and MDA5-IRF3/IRF7 pathway activation.
- MDA5 expression knockdown and assessment of EV-D68 replication.
- Evaluation of IFN-λ1 and IFN-λ2/3 antiviral activity.
Main Results:
- EV-D68 infection and vRNA transfection stimulated IFN-λ secretion in Calu-3 cells.
- The MDA5-IRF3/IRF7 pathway was identified as the key mediator of EV-D68-induced IFN-λ production.
- EV-D68 infection led to downregulation of MDA5, which enhanced viral replication upon knockdown.
- IFN-λ1 and IFN-λ2/3 proteins demonstrated significant inhibition of EV-D68 infection.
Conclusions:
- EV-D68 induces type III IFN production via the activated MDA5-IRF3/IRF7 pathway.
- Type III IFNs play a critical role in controlling EV-D68 replication in respiratory epithelial cells.
- Understanding this pathway provides potential targets for therapeutic interventions against EV-D68.
