Abstract:

Aim. In this study we aimed to investigate circulating blood cells during experimental virus-induced asthma exacerbation vs baseline. Materials and methods. Rhinovirus 16 (RV16) experimental infections were induced in RV16-seronegative moderate and mild atopic asthmatic and healthy non-atopic subjects. PBMC from 8 mild, 12 moderate asthmatics and 6 normal subjects obtained at baseline (14 day) and at day 4 after infection with RV16 were analyzed by flow cytometry. B-cells were identified as CD19+. Monocytes were identified as MHC II, CD14high cells. The MHC II, CD14neg-low cells were further classified by CD123 and CD11c expression into myeloid DC (CD11chigh, mDC), plasmacytoid DC (CD123+, pDC). Results. There were no differences at baseline in frequencies of blood monocytes, mDC and pDC in asthmatic compared to normal subjects, but we found increased amount of B-cells in asthma group (p < 0.05). At day 4 after RV16 infection we found decreased percentages of pDC in both moderate and mild asthmatics (p < 0.05) compared to baseline. Conclusion. These data suggest an increased migratory potential of circulating pDCs during virus-induced asthma exacerbation. In patients with asthma pDCs could be recruited to the airways. It is possible that the distinct subsets of DCs may be recruited at different time points to the effector sites of allergic inflammation.

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