Immunoglobulin E receptor complex (IgE–FcεRI complex)

The receptor-bound immunoglobulin E complex is formed when immunoglobulin E (IgE) binds to high-affinity FcεRI or low-affinity CD23 receptors on immune cell surfaces. This interaction is critical in the initiation of allergic reactions: cross-linking of FcεRI-bound IgE by a specific allergen induces mast cell or basophil activation, leading to degranulation and release of mediators such as histamine. In addition to immediate allergic responses, IgE–receptor complexes facilitate antigen presentation and immune cell maturation. Targeting this complex, particularly by preventing IgE–FcεRI interaction, forms the basis of several approved therapies for severe allergic disease.

Other names

Fc epsilon receptor-bound immunoglobulin E complexIgE–FcεRI complexIgE–CD23 complexIgE receptor complex

Blockade of IgE binding to FcεRI, reducing receptor sensitization on mast cells/basophils and downstream allergic reactions (as with omalizumab). Induction of FcεRI downregulation on effector cells (when free IgE is depleted).