FCER2
FCER2: The Receptor for IgE
Description
FCER2, also known as the low-affinity IgE receptor, is a protein receptor expressed on the surface of certain immune cells, including macrophages, dendritic cells, and mast cells. It binds to immunoglobulin E (IgE), an antibody class that is involved in allergic responses and defenses against parasitic infections.
FCER2 is composed of two distinct polypeptide chains: an alpha chain (α) and a beta chain (β). The α chain binds to IgE, while the β chain is responsible for signal transduction. Upon binding of IgE, FCER2 triggers the release of inflammatory mediators, such as histamine, leukotrienes, and cytokines, which promote allergic reactions.
Associated Diseases
Dysregulation of FCER2 expression or function has been implicated in several diseases, including:
- Allergies: FCER2 is the primary receptor for IgE on mast cells and basophils, which are key effector cells in allergic responses. Increased levels of FCER2 or IgE can lead to increased allergic reactions.
- Atopic dermatitis (eczema): FCER2 expression is elevated in eczema patients, suggesting its role in the development of this chronic inflammatory skin condition.
- Asthma: FCER2 is expressed on airway macrophages and eosinophils, which contribute to airway inflammation and bronchoconstriction in asthma.
- Immunodeficiencies: Mutations or deficiencies in FCER2 can impair IgE-mediated immunity, leading to recurrent infections with certain parasites.
Did you Know ?
Approximately 30% of the population has a genetic polymorphism in the FCER2 gene that results in a decreased affinity for IgE. This polymorphism has been associated with a lower risk of developing allergies.
