Fig. 5: IL-3 induced FcεRI on human basophils is functionally active.

Isolated primary human basophils were incubated with medium or IL-3 (10 ng/ml) overnight and sensitized with recombinant monomeric human NIP-specific JW8-IgE (100 nM) for 30 minutes. Surface IgE levels were determined by flow cytometry. a A representative histogram indicating the increase in fluorescence intensity (FI) upon incubation of IL-3 primed cells with IgE is shown. IgE levels on the surface of isolated basophils from different donors (n = 10) after overnight incubation with medium or IL-3 (10 ng/ml) and subsequent addition of IgE (100 nM) are compared b. IL-3 primed JW8-IgE-sensitized basophils were stimulated with increasing concentrations of NIP-7-BSA antigen. Activation was determined by measuring CD63 surface expression using flow cytometry. Representative dot plots are shown c. Quantification of antigen-challenged basophils from different donors that were incubated with or without IL-3 overnight and sensitized with or without JW8-IgE for 30 minutes (n = 3). Data are shown as mean values ± SEM