Human rhinoviruses (HRV) are a major cause of asthma exacerbations and hospitalization. Studies using primary cultures suggest that this may be due to impaired production of type I and type III IFNs by asthmatic bronchial epithelial cells. Although epithelial cells are the main target for HRV infection, HRV can be detected in the subepithelial layer of bronchial mucosa from infected subjects by in situ hybridization. Therefore, we postulated that submucosal fibroblasts are also involved in the innate antiviral response to HRV infection in asthma. We found that regardless of subject group, bronchial fibroblasts were highly susceptible to RV1b infection. IL-8 and IL-6 were rapidly induced by either HRV or UV-irradiated virus, suggesting that these responses did not require viral replication. In contrast, RANTES expression was dependent on viral replication. Regardless of disease status, fibroblasts did not respond to HRV infection with significant induction of IFN-, even though both groups responded to synthetic dsRNA with similar levels of IFN- expression. Exogenous IFN- was highly protective against viral replication. Our data suggest that fibroblasts respond to HRV with a vigorous proinflammatory response but minimal IFN- expression. Their susceptibility to infection may cause them to be a reservoir for HRV replication in the lower airways, especially in asthmatic subjects where there is reduced protection offered by epithelialderived IFNs. Their ability to support viral replication coupled with their vigorous proinflammatory response following infection may contribute to asthma exacerbations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.