ABOLITION OF ANAPHYLAXIS BY TARGETED DISRUPTION OF THE HIGH-AFFINITY IMMUNOGLOBULIN-E RECEPTOR ALPHA-CHAIN GENE

Mast cells and basophils, which are activated by immunoglobulin E (IgE ) and allergen, play a prominent role in anaphylaxis. However, they ex press at least three types of IgE receptor, including the high affinit y IgE receptor (FcepsilonRI). The relative contribution of these IgE r eceptors, and possibly other receptors such as FcepsilonRII/CD23 and M ac-2, to the genesis of in vivo anaphylaxis is still unclear. To addre ss this question, we have generated FcepsilonRI-deficient mice. These mice appear normal and express a normal number of mast cells, but they are resistant to cutaneous and systemic anaphylaxis. These data demon strate that FcepsilonRI is necessary for the initiation of IgE-depende nt anaphylactic reactions. Therefore, interfering with its function sh ould be an effective means of treating allergy, regardless of the alle rgen specificity.