You are currently viewing the summary.View Full Text
Mast cells initiate allergic reactions. These cells express a receptor (FcɛRI) that binds to immunoglobulin E (IgE). When antigen binds to receptor-bound IgE, a wide range of responses is triggered that together cause the symptoms of allergy. These include the release of enzymes and a variety of bioactive chemicals from granules, the generation of lipid-derived inflammatory molecules, and the secretion of multiple cytokines and chemokines. However, not all responses are equally induced. On page 1021 of this issue, Suzuki et al. (1) unravel how a difference in the affinity of antigen favors one response or another by switching between intracellular signaling pathways. Quantitative differences in antigen affinity thus determine the quality of mast cell responses.