High-affinity immunoglobulin epsilon receptor (FcεRI) and Immunoglobulin E (IgE) complex (FcεRI-IgE complex)

The high-affinity immunoglobulin epsilon receptor (FcεRI) complexed with Immunoglobulin E (IgE) on the surface of mast cells and basophils is the central mediator of type I hypersensitivity reactions (UniProt, 2024). This specific target refers to the state where the IgE molecules are specific for epitopes found in olive (e.g., Ole e 1) and timothy grass (e.g., Phl p 1, Phl p 5) allergens, which are major drivers of seasonal allergic rhinitis and asthma (WHO/IUIS, 2024). When these environmental allergens encounter the sensitized effector cells, they cross-link the IgE-FcεRI complexes, triggering a signal transduction cascade that leads to the immediate release of inflammatory mediators like histamine, leukotrienes, and cytokines (PubMed, 2022). This physiological response is responsible for the clinical symptoms of allergy, ranging from sneezing and itching to severe bronchoconstriction. Therapeutic strategies such as the monoclonal antibody omalizumab work by binding to the Fc region of free IgE, preventing its interaction with FcεRI and leading to a significant reduction in receptor density on the cell surface (NIH, 2023). This target is a primary focus for treating severe allergic conditions and for developing allergen-specific immunotherapies aimed at inducing long-term immune tolerance.

Other names

Fc epsilon RIFCER1High-affinity IgE receptorIgE-FcεRI axisIgE-bound FcεRI

Monoclonal antibodies bind to the Cε3 domain of circulating free IgE, preventing its interaction with the high-affinity FcεRI receptor on effector cells and subsequently leading to the downregulation of receptor expression (StatPearls, 2023).