IL-3^-/- BMMCs show impaired survival on IgE stimulation. (A) IgE-induced survival of IL-3^-/- BMMCs. Survival of BMMCs from WT (IL-3^+/+) and IL-3^-/- mice was assayed in the presence of 10 ng/mL IL-3 (▴) or IgE (DNP-H1-ϵ-26). IgE concentrations of 0 μg/mL (○), 1 μg/mL (⬡), and 10 mg/mL (▵) are also included. (B) IgE(-Ag)–induced survival in Jak3^-/- BMMCs. WT (Jak3^+/+) and Jak3^-/- BMMCs were tested for survival in the presence of IgE or 10 ng/mL IL-4 (▵). (C) Survival of IL-3^-/- BMMCs induced by other IgE clones. Survival induced by 10 μg/mL anti–TNP IgE (C38-2; ⬡) and anti–TNP IgE (C48-2 ▵) was assayed as described in panel A. Data are expressed as means ± SD for triplicate assays. Similar results were obtained from 3 independent pairs.