Fig. 4: IL-3-mediated increase of surface FcεRI levels.

Isolated primary human basophils were incubated for 24 h with medium, IL-3 (10 ng/ml), Sus11-IgE (100 nM) or IL-3 and IgE in combination a, different concentrations of IL-3 (0.1−10 ng/ml) b, IL-3 (10 ng/ml), GM-CSF (10 ng/ml) or IL-5 (10 ng/ml) c. FcεRI surface levels were determined by flow cytometry and the percentage change compared to initial geometric mean fluorescence intensities are shown. The correlation between the initial FcεRI level with the FcεRI level after 24-hour incubation with IL-3 (10 ng/ml) on the surface of basophils isolated from different donors (n = 10) is displayed d. FcεRI levels on the surface of isolated basophils from different donors (n = 10) after 24-hour incubation with either medium or IL-3 (10 ng/ml) are compared e. Normalized and log2-transformed gene expression results for FCERIA (FcεRIα), MS4A2 (FcεRIβ), and FCERIG (FcεRIγ) are shown from two independent arrays using pooled basophil RNA of three individual donors after incubation with medium or IL-3 for 4 or 18 h f. The relative log2 fold change (RLFC) of IL-3-treated basophils is shown as a heat-map for the indicated genes g. Data are shown as mean values ± SEM