TSLP stimulates eosinophil degranulation, as measured by EDN release, through a TSLPR specific interaction. (A) Stimulation of eosinophil EDN release, as a percent of total EDN, by TSLP (1 μg/ml) is compared to IL-5 (1 ng/ml) and FMLP (10−7 M) stimulated release (n = 6). (B) The dose response curve of EDN release, as a percent of total EDN minus unstimulated release, from stimulation with TSLP (0 μg/ml, n = 4; 0.2 μg/ml, n = 3; 0.5 μg/ml, n = 3; 1.0 μg/ml, n = 4; 2.0 μg/ml, n = 3). (C) A functional blocking antibody to TSLPR or isotype control (2.5 μg/ml) was incubated with eosinophils prior to stimulation with TSLP. The data are expressed as the percent of TSLP stimulated EDN release (n = 3). *Statistically different from unstimulated (p < 0.05).