IgE and Mast Cells: The Endogenous Adjuvant.

Mast cells and immunoglobulin E (IgE) are most familiar as the effectors of type I hypersensitivity reactions including anaphylaxis. It is becoming clear however that this pair has important immunomodulatory effects on innate and adaptive cells of the immune system. In this purview, they act as endogenous adjuvants to ignite evolving immune responses, promote the transition of allergic disease into chronic illness, and disrupt the development of active mechanisms of tolerance to ingested foods. Suppression of IgE-mediated mast cell activation can be exerted by molecules targeting IgE, FcɛRI, or signaling kinases including Syk, or by IgG antibodies acting via inhibitory Fcγ receptors. Recent reports indicate that such interventions have promise in the development of strategies to treat allergic disease.