Allergen-specific B and T lymphocyte receptors (BCR/TCR)

Allergen-specific B and T lymphocyte receptors are the molecular gatekeepers of the allergic immune response, responsible for the recognition of environmental antigens (allergens) and the subsequent initiation of Type I hypersensitivity. The B-cell receptor (BCR), particularly the membrane-bound IgE isotype, and the T-cell receptor (TCR) on Th2 cells work in concert to drive the production of allergen-specific IgE and the activation of effector cells like mast cells and basophils. In allergic diseases such as asthma, hay fever, and food allergy, these receptors are inappropriately activated by harmless substances, leading to chronic inflammation and acute allergic reactions. Therapeutic interventions targeting these receptors, such as allergen immunotherapy (AIT) and peptide-based vaccines, aim to reprogram the immune system toward tolerance by inducing T-cell anergy, promoting regulatory T-cell (Treg) differentiation, and shifting B-cell class switching from IgE to IgG4. Emerging precision medicines, including CAR-T cells and TCR-mimic antibodies, are also being explored to specifically deplete or modulate these pathogenic lymphocyte clones, offering the potential for long-term disease modification.

Other names

Allergen-reactive B and T cell receptorsAllergen-specific BCR and TCRAntigen-specific lymphocyte receptors (allergen-specific)IgE-BCR and TCR complex

Allergen-specific immunotherapy (AIT) and related therapies work by modulating the activity of allergen-specific B and T cell receptors to induce immunological tolerance. AIT involves repeated exposure to allergens, leading to the induction of regulatory T cells (Tregs) and B cells (Bregs), a shift from Th2 to Th1 cytokine profiles, and the production of 'blocking' IgG4 antibodies that compete with IgE for allergen binding (Source: NIH, PubMed). Peptide-based therapies specifically target the T-cell receptor (TCR) to induce anergy or deletion of allergen-reactive T cells without cross-linking IgE on mast cells (Source: PubMed). Anti-IgE therapies like Omalizumab bind to free and membrane-bound IgE (BCR), reducing effector cell sensitivity and potentially modulating B-cell activation (Source: PubMed).