Effect of preincubation with IL-4 on mast cell adhesion.

(A) Adhesion of mast cells precultured with SCF alone (as in Figure 1A) compared with mast cells precultured with IL-4 in addition to SCF (indicated in brackets). Adhesion assays were carried out in the presence or absence of 100 ng/mL (54 nM) SCF. Means ± SD are shown (n = 4). *P < .05 for significant difference (2-tailed paired t test) between mast cells precultured with SCF alone or with SCF and IL-4. (B) Dose dependency of the effect of IL-4. Mast cells were precultured for 14 days with various concentrations of IL-4 (in addition to SCF) indicated on the x-axis. Adhesion assays were carried out in the presence or absence of 100 ng/mL (54 nM) SCF. Results represent the mean ± SD of 3 experiments.