Allergen-specific B Cell Receptor (Allergen-specific BCR)

An allergen-specific B cell receptor (BCR) is a membrane-bound immunoglobulin molecule expressed on the surface of B cells that specifically recognizes and binds to allergens—substances capable of triggering allergic immune responses. Each B cell expresses a unique BCR with specificity determined by its variable regions, allowing it to bind only particular epitopes present on an allergen. The primary function is to recognize allergens via its variable regions exposed on the cell surface. This binding event initiates intracellular signaling cascades that activate the B cell. Following activation by their cognate allergen, some activated B cells undergo class-switch recombination to produce plasma cells secreting allergen-specific antibodies—most notably IgE. Secreted allergen-specific IgE binds high-affinity FcεRI receptors on mast cells and basophils. Cross-linking these receptors upon subsequent exposure leads to degranulation and release of mediators responsible for immediate hypersensitivity reactions. Memory B cells specific for allergens contribute to long-term sensitization; they rapidly respond upon re-exposure even after prolonged periods without contact with the original antigen/allergen.

Other names

Allergen-specific immunoglobulinBCR specific for allergenAllergy-related B cell receptor

Omalizumab binds to IgE, preventing it from binding to mast cells and basophils, thus preventing degranulation upon allergen exposure. BCR signaling inhibitors block downstream signaling pathways triggered by allergen binding, preventing B cell activation and antibody production. Allergen-specific immunotherapy aims to induce tolerance by gradually exposing the individual to the allergen, modifying the B cell response.