T cell receptor-MHC-peptide complex (Dermatophagoides pteronyssinus and Dermatophagoides farinae allergens) (HDM TCR-pMHC complex)

The T cell receptor-MHC-peptide complex involving Dermatophagoides pteronyssinus and Dermatophagoides farinae allergens is the central molecular assembly that initiates and sustains allergic responses to house dust mites (HDM) [3, 6]. In this complex, CD4+ T cell receptors (TCRs) recognize specific immunodominant peptides, such as those from Der p 1, Der p 2, Der f 1, and Der f 2, which are processed and presented by Major Histocompatibility Complex (MHC) Class II molecules on antigen-presenting cells [2, 16, 18]. This recognition event triggers the activation and expansion of allergen-specific Th2 cells, which secrete cytokines like IL-4, IL-5, and IL-13 [3, 17]. These cytokines drive IgE production and eosinophilic inflammation characteristic of allergic asthma, rhinitis, and atopic dermatitis [8, 9, 13]. Therapeutic interventions targeting this complex, primarily allergen immunotherapy (AIT) and experimental peptide-based vaccines, aim to reprogram the immune system toward tolerance [4, 7, 12]. These treatments work by inducing T cell anergy, deletion, or a shift toward a regulatory T cell (Treg) phenotype [3, 11, 12]. This shift reduces the hypersensitivity response upon subsequent environmental exposure to HDM allergens by promoting the production of blocking antibodies like IgG4 [4, 7, 15]. Understanding the structural basis of this trimolecular interaction is crucial for developing more effective and safer desensitization therapies [20, 22].

Other names

House dust mite allergen-MHC-TCR complexDer p/Der f peptide-MHC-TCR complexHDM T-cell epitope complexDermatophagoides allergen-MHC-TCR complexHDM-specific T cell receptor complex

Induction of immune tolerance through T cell anergy, T cell deletion, immune deviation from Th2 to Th1/Treg profiles, and the production of blocking IgG4 antibodies [3, 4, 12].