This was accompanied by reduced expression of intra-cellular signalling molecules Fludrocortisone acetate including interferon regulatory factors, STAT1 and several members of the NF-kB family. In contrast, expressions of TLR8, IRF5 and IFNAR were similar after HRV stimulation in cells from asthmatic and healthy donors. These observations could not be attributed to alterations in the numbers of antigen presenting cells, or expression of ICAM-1, TLR7 or TLR8 at baseline, prior to HRV exposure. Many investigators have proposed that a dysregulated innate immune response to respiratory viruses such as HRV is an important feature of asthma, though there is relatively little understanding of the mechanisms involved. Our findings confirm and extend previous reports that circulating immune cells from people with asthma have a lower capacity to express type-I IFNs or IFN-related genes. This is in contrast to the recent report of Sykes et al, who recently reported reductions in HRV-induced IFNa and IFNb in wellcontrolled asthma were largely confined to lung cells, with no differences observed between PBMC from asthmatic and healthy donors. The differences observed between our findings and those reported by Sykes et al could be due to phenotypic differences between study cohorts, including inflammatory phenotype, asthma severity and asthma control. Variations in the degree of atopy, FceR1 expression and extent of recent allergen exposure are also plausible reasons for variations in findings between different laboratories. FceR1 cross-linking on peripheral blood pDC impairs the capacity to mount an anti-viral response. Deficiencies in the capacity of HRV-stimulated PBMC to secrete type-I IFN in asthmatic children were most evident after cross-linking FceR1 and deficits in the D-Sorbitol ability of patients with allergic rhinitis to secrete IFNa have been described in pDC from both the nasal mucosa and peripheral blood. More prosaic experimental factors such as virus strain and concentration, and the capacity of different assays to measure multiple IFNa subtypes may also be relevant.