A range of C∊3–C∊4 interdomain angles in IgE Fc accommodate binding to its receptor CD23
نویسندگان
چکیده
The antibody IgE plays a central role in allergic disease, functioning principally through two cell-surface receptors: FcℇRI and CD23. FcℇRI on mast cells and basophils mediates the immediate hypersensitivity response, whilst the interaction of IgE with CD23 on B cells regulates IgE production. Crystal structures of the lectin-like `head' domain of CD23 alone and bound to a subfragment of IgE consisting of the dimer of Cℇ3 and Cℇ4 domains (Fcℇ3-4) have recently been determined, revealing flexibility in the IgE-binding site of CD23. Here, a new crystal form of the CD23-Fcℇ3-4 complex with different molecular-packing constraints is reported, which together with the earlier results demonstrates that conformational variability at the interface extends additionally to the IgE Fc and the quaternary structure of its domains.
منابع مشابه
Role of IgE Low-Affinity Receptor (CD23) in Pathogenesis of Nasal Polyp
Background: Nasal polyps, a common clinical problem, are characterized by eosinophilic and mast cell inflammation. The role of allergy and IgE in pathogenesis of nasal polyps is still unclear. IgE receptors are important components of the immunological pathway in allergic and inflammatory diseases. Objective: To determine if the low affinity IgE receptor (CD23) is presented on nasal polyp tis...
متن کاملHuman neutrophils express the high-affinity receptor for immunoglobulin E (Fc«RI): role in asthma
Polymorphonuclear neutrophils (PMNs) are important effector cells in host defense and the inflammatory response to antigen. The involvement of PMNs in inflammation is mediated mainly by the Fc receptor family, including IgE receptors. Recently, PMNs were shown to express two IgE receptors (CD23/Fc«RII and galectin-3). In allergic diseases, the dominant role of IgE has been mainly ascribed to it...
متن کاملIgE binds asymmetrically to its B cell receptor CD23
The antibody IgE plays a central role in allergic disease mechanisms. Its effector functions are controlled through interactions between the Fc region and two principal cell surface receptors FcεRI and CD23. The interaction with FcεRI is primarily responsible for allergic sensitization and the inflammatory response, while IgE binding to CD23 is involved in the regulation of IgE synthesis and al...
متن کاملCrystal structure of IgE bound to its B-cell receptor CD23 reveals a mechanism of reciprocal allosteric inhibition with high affinity receptor FcεRI.
The role of IgE in allergic disease mechanisms is performed principally through its interactions with two receptors, FcεRI on mast cells and basophils, and CD23 (FcεRII) on B cells. The former mediates allergic hypersensitivity, the latter regulates IgE levels, and both receptors, also expressed on antigen-presenting cells, contribute to allergen uptake and presentation to the immune system. We...
متن کاملThe binding site on human immunoglobulin E for its high affinity receptor.
Immunoglobulin (Ig) E antibodies mediate allergic responses by binding to specific high affinity receptors, Fc epsilon RI, on mast cells and basophils. Previous studies have shown that the principal Fc epsilon RI binding site is located on the third constant domain, Fc epsilon 3, of IgE. Based on a model of the IgE Fc epsilon 3 (which is homologous to the second constant domain of IgG), homolog...
متن کامل