Fig. 1

Regulation of allergen uptake of pDC varies among different allergens. PDC isolated from fresh peripheral blood or buffy coats by BDCA-4 positive magnetic bead selection were cultured overnight in AIM-V medium containing 10 ng/ml IL-3 in the presence or absence of CpG ODN 2006 (2,5 µg/ml), IL-4 (500 U/ml) or IL-13 (100 U/ml) or allergen as indicated. Prior to incubation, allergens were labeled using an Alexa Fluor 555 staining kit as described in Material and Methods. Allergen concentrations were 20 µg/ml for Der p 1 and 10 µg/ml for OVA and Api. After incubation, surface staining was performed with FITC conjugated Lin-1 and PerCP Cy5.5 conjugated CD123 and allergen uptake was analyzed by flow cytometry. PDC were defined as Lin-1⁻/CD123⁺⁺ cells with pDC comprising 24–50%. A Dot plots show examples of allergen uptake regulation, which are summarized in (B–D), where box plots show percentages of allergen-positive pDC, central horizontal lines indicate medians, box borders represent IQR, whiskers indicate minima and maxima. B n = 6, C n = 5, D n = 8 experiments. Significance levels were assessed by Friedman test with p-values: ** p < 0.005 and * p < 0.05