[HTML][HTML] MDA5 and TLR3 initiate pro-inflammatory signaling pathways leading to rhinovirus-induced airways inflammation and hyperresponsiveness

Q Wang, DJ Miller, ER Bowman, DR Nagarkar… - PLoS …, 2011 - journals.plos.org
Q Wang, DJ Miller, ER Bowman, DR Nagarkar, D Schneider, Y Zhao, MJ Linn, AM Goldsmith…
PLoS pathogens, 2011journals.plos.org
Rhinovirus (RV), a single-stranded RNA picornavirus, is the most frequent cause of asthma
exacerbations. We previously demonstrated in human bronchial epithelial cells that
melanoma differentiation-associated gene (MDA)-5 and the adaptor protein for Toll-like
receptor (TLR)-3 are each required for maximal RV1B-induced interferon (IFN) responses.
However, in vivo, the overall airway response to viral infection likely represents a
coordinated response integrating both antiviral and pro-inflammatory pathways. We …
Rhinovirus (RV), a single-stranded RNA picornavirus, is the most frequent cause of asthma exacerbations. We previously demonstrated in human bronchial epithelial cells that melanoma differentiation-associated gene (MDA)-5 and the adaptor protein for Toll-like receptor (TLR)-3 are each required for maximal RV1B-induced interferon (IFN) responses. However, in vivo, the overall airway response to viral infection likely represents a coordinated response integrating both antiviral and pro-inflammatory pathways. We examined the airway responses of MDA5- and TLR3-deficient mice to infection with RV1B, a minor group virus which replicates in mouse lungs. MDA5 null mice showed a delayed type I IFN and attenuated type III IFN response to RV1B infection, leading to a transient increase in viral titer. TLR3 null mice showed normal IFN responses and unchanged viral titers. Further, RV-infected MDA5 and TLR3 null mice showed reduced lung inflammatory responses and reduced airways responsiveness. Finally, RV-infected MDA5 null mice with allergic airways disease showed lower viral titers despite deficient IFN responses, and allergic MDA5 and TLR3 null mice each showed decreased RV-induced airway inflammatory and contractile responses. These results suggest that, in the context of RV infection, binding of viral dsRNA to MDA5 and TLR3 initiates pro-inflammatory signaling pathways leading to airways inflammation and hyperresponsiveness.
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