Figure 4.

Absence of Stx3, but not Stx4, alters mainly regulated exocytosis in MCs. PCMCs were sensitized with anti-DNP IgE and then challenged with DNP-HSA (DNP) or PI. The color key in A and B applies to all panels. Regulated exocytosis was monitored by measuring the fraction of total cell β-hexosaminidase (A–C) and the amount of histamine (D and E) secreted 30 min post-stimulation with PI. Constitutive exocytosis was monitored by measuring secretion of TNFα (F) and IL4 (G) 6 h post-stimulation with PI. Secretion independent of exocytosis was monitored by measuring PGD₂ (H) and LTC₄ (I) 30 min post-stimulation. n = cells derived from 7–8 mice of each genotype; circle and white line, mean; error bar, S.E.; box, 25th–75th percentile; whiskers, 5th–95th percentile. #, p ≤ 0.05; *, p ≤ 0.001; all compared with +/+ PCMCs unless otherwise specified.