Interferon-β induces a long-lasting antiviral state in human respiratory epithelial cells.

Summary Objectives Interferon-β (IFNβ) induces strong antiviral effects and is therefore an attractive agent to prevent or reduce the incidence of virus-mediated exacerbations in asthmatic or chronic obstructive pulmonary disease (COPD) patients. We therefore investigated the effects of prophylactic IFNβ on respiratory epithelial cells infected with rhinovirus (RV). Methods A549 cells and primary bronchial epithelial cells (PBECs) were exposed for 18 h to IFNβ. Then, IFNβ was either removed or maintained in the supernatant for the rest of the experiment and cells were infected with RV-1B at t  = 0 or 72 h after the initial exposure to IFNβ. Results Viral RNA levels were decreased in both cell types. Furthermore, both viral RNA and infectious virus levels in the supernatant of infected A549 cells were still significantly reduced at 72 h after removal of IFNβ. This pronounced antiviral pre-treatment effect was associated with increased expression of the antiviral genes IFN-stimulated protein of MR15000 (ISG15) and Myxovirus resistance 1 (Mx1) and the effect was maintained even when IFNβ levels in the supernatant of A549 cells were undetectable. Conclusions These data show that IFNβ has not only a strong, but also a long-lasting protective effect against RV infection of respiratory epithelium.