Immunoglobulin E antibody bound to high-affinity immunoglobulin epsilon receptor I (IgE–FcεRI complex)

Immunoglobulin E (IgE) is a class of antibody that, when bound to its high-affinity receptor Fc epsilon RI (FcεRI) on mast cells and basophils, is central to allergic and anaphylactic responses. The FcεRI is a multimeric cell-surface receptor consisting of one α subunit (which binds IgE), one β subunit, and two disulfide-linked γ subunits (αβγ₂ in tetrameric form). Upon cross-linking by multivalent antigens (allergens), the IgE–FcεRI complex triggers cell activation via immunoreceptor tyrosine-based activation motifs (ITAMs), leading to cellular degranulation, and release of inflammatory mediators such as histamine, prostaglandins, and cytokines[1][2][3][4][6][7][9]. This response is responsible for the rapid onset of type I hypersensitivity reactions including asthma, rhinitis, urticaria, and anaphylaxis. FcεRI is also expressed on dendritic cells and monocytes, where it mediates antigen uptake and presentation[3][4]. The IgE–FcεRI interaction is a well-validated therapeutic target in allergic diseases, with anti-IgE biologic drugs such as omalizumab and ligelizumab in clinical use to disrupt the antibody-receptor complex and prevent downstream allergic inflammation[4][5][6]. **Clarification:** The target "IgE antibodies bound to FcεRI receptors" describes a *complex* between an antibody (IgE) and its receptor (FcεRI), rather than a single molecular target. In drug discovery resources, this level of specificity (antibody–receptor complex) is sometimes referred to in the context of mechanism of action, but more commonly the individual components ("Immunoglobulin epsilon receptor I" and "Immunoglobulin E") are cataloged as targets. The above information is structured according to conventions for molecular targets, but note that the description represents a *complex* rather than a single molecule, which may deviate from strict single-gene or single-protein annotation. The target name is not misspelled, but is a higher-order complex; thus, **is_incorrect: true** to flag this for further curation or normalization depending on your schema.

Other names

IgE–FcεRIIgE–Fc epsilon RIimmunoglobulin E–Fc epsilon receptor I complexhigh-affinity IgE receptor complexFcεRI–IgE

Inhibition of IgE binding to FcεRI (by anti-IgE antibodies preventing complex formation), FcεRI blockade, Downregulation of FcεRI expression, Interruption of IgE-mediated signaling, Inhibition of mast cell/basophil degranulation