Regulation of mediator secretion in human basophils by p38 mitogen-activated protein kinase: phosphorylation is sensitive to the effects of phosphatidylinositol 3-kinase inhibitors and calcium mobilization.

Although human basophils modulate allergic diseases by secreting histamine, leukotriene C(4), interleukin (IL)-4, and IL-13, the intermediary signals controlling the release of these mediators are poorly understood. Here, we show that p38 mitogen-activated protein kinase (MAPK) crucially affects basophil activation following stimulation with various secretagogues. Phosphorylation of p38 MAPK occurred within 5 min following anti-immunoglobulin (Ig)E stimulation, but was more rapidly activated in basophils stimulated with formyl-Met-Leu-Phe or A23187.