High-affinity IgE receptor (FcεRI) bound to House Dust Mite-specific Immunoglobulin E (FcεRI-HDM-IgE complex)

The complex formed by House Dust Mite (HDM)-specific Immunoglobulin E (IgE) bound to the high-affinity IgE receptor (FcεRI) on mast cells and basophils is the primary effector unit in HDM-mediated allergic diseases (Sutton & Gould, 1993). In sensitized individuals, these effector cells are primed with IgE antibodies specific to HDM allergens, such as Der p 1 and Der p 2. Upon exposure to these allergens, the IgE-FcεRI complexes are cross-linked, triggering an intracellular signaling cascade that leads to the rapid degranulation and release of inflammatory mediators like histamine and leukotrienes (Galli et al., 2008). This physiological process underlies the clinical symptoms of allergic asthma, rhinitis, and atopic dermatitis (Thomas et al., 2010). Therapeutic strategies like omalizumab target the free IgE pool to prevent the formation of these complexes and induce the downregulation of FcεRI on the cell surface (MacGlashan et al., 1997). Additionally, allergen-specific immunotherapy (AIT) works by inducing IgG4 antibodies that intercept allergens before they can bind to the pre-existing IgE-FcεRI complex, thereby preventing cell activation (Akdis & Akdis, 2014).

Other names

HDM-specific IgE-FcεRI complexSensitized mast cell IgEFc epsilon RI-IgE complexSurface-bound HDM-IgE

Anti-IgE monoclonal antibodies sequester free IgE to prevent its attachment to FcεRI and lead to a gradual reduction in the density of pre-existing IgE-FcεRI complexes through receptor downregulation (MacGlashan et al., 1997). Allergen-specific immunotherapy induces the production of allergen-specific IgG4 antibodies that act as decoys, intercepting HDM allergens before they can cross-link the IgE bound to mast cells and basophils (Akdis & Akdis, 2014).