Allergen-specific T-cell receptor (TCR) (TCR)

The allergen-specific T-cell receptor (TCR) is a heterodimeric surface protein on T lymphocytes that recognizes specific peptide fragments of allergens presented by Major Histocompatibility Complex (MHC) molecules on antigen-presenting cells (Janeway's Immunobiology). In allergic individuals, these TCRs typically reside on Th2 cells, which orchestrate the allergic inflammatory response through the secretion of cytokines like IL-4 and IL-13 (Akdis & Akdis, 2014). PURETHAL is a subcutaneous immunotherapy (SCIT) product containing glutaraldehyde-modified allergens (allergoids) that maintain T-cell epitopes while reducing IgE-binding capacity for improved safety (HAL Allergy). The therapeutic interaction between PURETHAL-derived peptides and the TCR aims to reprogram the immune system toward tolerance, primarily through the induction of IL-10-secreting regulatory T cells (Tregs) (Pfaar et al., 2014). This modulation leads to a decrease in allergen-specific IgE and an increase in "blocking" IgG4 antibodies, which compete for allergen binding and inhibit mast cell degranulation (Larche et al., 2006). Consequently, the TCR serves as the critical molecular gatekeeper for the induction of long-term clinical desensitization in patients with allergic rhinitis and asthma.

Other names

T-cell antigen receptorAllergen-reactive T-cell receptorT-cell receptor alpha/beta

Allergen immunotherapy (AIT) involves the presentation of allergen-derived peptides by MHC molecules to allergen-specific T-cell receptors (TCRs). This interaction, particularly with modified allergoids like those in PURETHAL, induces immune tolerance by promoting the differentiation of regulatory T cells (Tregs) and shifting the cytokine profile from Th2 (pro-allergic) to Th1 or Treg (anti-inflammatory), resulting in the production of protective IgG4 antibodies.