BACKGROUND: Respiratory viral infection, including respiratory syncytial virus (RSV) and rhinovirus, has been linked to respiratory disease in pediatric patients, including severe acute bronchiolitis and asthma exacerbation. OBJECTIVE: The study examined the role of the epithelial-derived cytokine thymic stromal lymphopoietin (TSLP) in the response to RSV infection. METHODS: Infection of human airway epithelial cells was used to examine TSLP induction after RSV infection. Air-liquid interface cultures from healthy children and children with asthma were also tested for TSLP production after infection. Finally, a mouse model was used to directly test the role of TSLP signaling in the response to RSV infection. RESULTS: Infection of airway epithelial cells with RSV led to the production of TSLP via activation of an innate signaling pathway that involved retinoic acid induced gene I, interferon promoter-stimulating factor 1, and nuclear factor-kappaB. Consistent with this observation, airway epithelial cells from asthmatic children a produced significantly greater levels of TSLP after RSV infection than cells from healthy children. In mouse models, RSV-induced TSLP expression was found to be critical for the development of immunopathology. CONCLUSION: These findings suggest that RSV can use an innate antiviral signaling pathway to drive a potentially nonproductive immune response and has important implications for the role of TSLP in viral immune responses in general.