Histamine release, cysteinyl leukotriene generation, and IL-4 secretion after stimulation through LIR7 with and without IL-3 priming. PBMCs (A-B) or highly purified (C) basophils were either incubated with 10 ng/mL IL-3 or not, incubated with IgG₁ control antibody (▪) or with mAb to LIR7 (□) and stimulated by addition of goat anti-mouse IgG for 45 minutes (A-B) or 4 hours (C). Supernatants were assayed for (A) histamine (n = 3), (B) cysteinyl leukotrienes (CysLT, n = 3), and (C) IL-4 (n = 3) by EIA.