Figure 1. Rat and human mast cell systems and activation by highly cytokinergic SPE-7 IgE.
(A) The number of rat FcεRI molecules expressed per RBL-2H3 and human FcεRI molecules expressed per LAD-2 mast cells were quantified by Qifikit® (Dako). RBL-2H3 cells express 0.8 ± 0.2 × 105 rat FcεRI molecules per cell and naïve LAD-2 cells and those primed with 6 ng/ml IL-4 for 5 days express 0.7 ± 0.3 × 105 and 1.7 ± 0.2 × 105 human FcεRI molecules per cell, respectively (n = 4, 6, and 12, respectively). (B) RBL-2H3 degranulation (over 14% baseline; n = 3–6), (C) LAD-2 mast cell degranulation (over 9% baseline; n = 7), and (D) LAD-2 TNF-α release (over 42 ng/ml baseline; n = 7), evoked by highly cytokinergic SPE-7 IgE. All data are shown as mean ± SEM. Statistically significant difference was determined by one-way ANOVA with Tukey's post-test; *** p < 0.001, * p = 0.01 to 0.05