Figure 2.

Human mast cells stimulated via the FcεRI secrete IL-11 (A) Production of IL-11 by 3 different populations (from Donors 4–6) of human umbilical cord blood-derived mast cells (> 99% purity) that were incubated for 6 h without anti-IgE ("0") or were maintained for 6 h after stimulation via the FcεRI with anti-IgE at 10 μg/ml. Data represent mean ± s.e.m. for 2–3 determinations for each population. (B) Kinetics of IL-11 production in human umbilical cord blood-derived mast cells after stimulation via the FcεRI with anti-IgE at 1 μg/ml. Data represent mean ± s.e.m. for 3 different populations of human mast cells (from Donors 7–9). Values for anti-IgE stimulated vs. control cells were analyzed for statistical significance by the Student's t test, 2-tailed. Note: In ~20 experiments of this type, little or no IL-11 secretion was detected in supernatants of mast cell preparations that were sensitized with IgE and then incubated without anti-IgE for 6 h.