Fig 1: Plasmacytoid DC kinetics in the skin upon in vivo allergen challenge. Immunofluorescence staining was performed on skin biopsies and examined by confocal microscopy. Counterstaining was performed with Hoechst to visualize nuclear DNA (blue, column 1). PDCs were stained with a monoclonal antibody against BDCA-2 and envisioned with a secondary goat anti-mouse antibody conjugated with AF488 (green, column 2). Column 3 is the result of merging columns 1 and 2. Representative microphotographs (×100) of pDCs are shown 24 h after the first challenge at the diluent (a) and allergen sites (b) and after the sixth challenge at the allergen site (c). PDC numbers were not significantly altered between different time-points, although a trend for increased pDCs was observed after the sixth allergen challenge (d). Data are expressed as median with interquartile range (first and third quartiles). *P < 0.05, WBC: whole blood cells.