IMMUNOLOGY

Detailed explanation-1: -IgE is mostly found bound to FcRI receptors on the mast cell, and very little IgE is found as a soluble antibody in circulation. When an antigen comes in contact with the mast cell, it crosslinks two or more FcRI molecules and activates the release of granules from the mast cell (13).

Detailed explanation-2: -IgE binds to two types of Fc receptors, called Fc epsilon R1 (or high-affinity Fc epsilon R) and Fc epsilon R2 (or low-affinity Fc epsilon R). The Fc epsilon R1 is composed of four polypeptide chains, one alpha, one beta, and two gamma chains.

Detailed explanation-3: -Cross-linking of the IgE-FcRI complex triggers mast cell activation and the release of substances that cause the symptoms of allergy (Figure 1A; Kinet, 1999). Allergic reactions occur within minutes of allergen exposure, differing thereby from other immune responses, which occur on a longer timescale.