High affinity immunoglobulin epsilon receptor subunit alpha (FcεRIα) complexed with Artemisia-specific IgE (FcεRI-IgE (Artemisia))

The complex of Artemisia-specific IgE bound to the high-affinity IgE receptor (FcεRI) is the primary molecular trigger for mugwort-induced Type I hypersensitivity reactions [1]. Artemisia (mugwort) pollen contains major allergens, such as Art v 1, which bind to and cross-link these IgE-FcεRI complexes on the surface of mast cells and basophils [2]. This cross-linking event initiates an intracellular signaling pathway that results in the rapid degranulation and release of pro-inflammatory mediators, including histamine, proteases, and leukotrienes, which drive the clinical symptoms of allergic rhinitis, conjunctivitis, and allergic asthma [3, 4]. While FcεRI is primarily expressed on mast cells and basophils, its interaction with IgE is the primary target for therapeutic intervention in severe allergic diseases [5]. Therapeutic strategies targeting this complex include monoclonal antibodies like omalizumab, which binds to the Fc region of circulating IgE, preventing its attachment to FcεRI and subsequently reducing the density of the receptor on cell surfaces [5]. Managing this target is crucial for patients with severe, refractory Artemisia-pollen-induced allergies who do not respond to standard antihistamine or corticosteroid treatments [6].

Other names

Artemisia-specific IgE bound to FcεRI on mast cells, basophils, and B cellsMugwort-specific IgE-FcεRI complexArtemisia pollen allergen-IgE-FcεRI complexIgE-FcεRI complex

Omalizumab binds to the Cε3 domain of free IgE, preventing its interaction with the high-affinity FcεRI receptor on mast cells and basophils, thereby inhibiting the allergic cascade and downregulating receptor expression.