Respiratory syncytial virus infection induces a subset of types I and III interferons in human dendritic cells

Whether respiratory syncytial virus (RSV) induces severe infantile pulmonary disease may depend on viral strain and expression of types I and III interferons (IFNs). These IFNs impact disease severity by inducing expression of many anti-viral IFN-stimulated genes (ISGs). To investigate the impact of RSV strain on IFN and ISG expression, we stimulated human monocyte-derived DCs (MDDCs) with either RSV A2 or Line 19 and measured expression of types I and III IFNs and ISGs. At 24 h, A2 elicited higher ISG expression than Line 19. Both strains induced MDDCs to express genes for IFN-beta, IFN-alpha l, IFN-alpha 8, and IFN-lambda 1-3, but only A2 induced IFN-alpha 2,-alpha 14 and-alpha 21. We then show that IFN-alpha 8 and IFN-alpha 14 most potently induced MDDCs and bronchial epithelial cells (BECs) to express ISGs. Our findings demonstrate that RSV strain may impact patterns of types I and III IFN expression and the magnitude of the ISG response by DCs and BECs.