House dust mite allergen peptide-HLA class II complex (HDM pMHC-II)

The House dust mite (HDM) allergen peptide-HLA class II complex is a molecular assembly consisting of processed HDM allergen fragments (such as those from Der p 1, Der p 2, or Der p 23) bound to the groove of Human Leukocyte Antigen (HLA) class II molecules (Wambre et al., 2011, PubMed). This complex is displayed on the surface of professional antigen-presenting cells, where it is recognized by the T-cell receptors (TCRs) of allergen-specific CD4+ T cells (Larché, 2007, PubMed). In allergic individuals, this recognition typically triggers a Th2-polarized immune response, characterized by the secretion of cytokines like IL-4, IL-5, and IL-13, which drive IgE production and eosinophilic inflammation (Cezmi et al., 2015, Nature Reviews Immunology). This interaction is the fundamental driver of clinical symptoms in HDM-induced allergic asthma, rhinitis, and atopic dermatitis. Therapeutic targeting of this complex primarily involves allergen-specific immunotherapy (AIT) or peptide-based vaccines like HDM-SPIRE (ToleroMune HDM). These treatments aim to modify the immune system's response to the pMHC-II complex by inducing immunological tolerance, often through the expansion of regulatory T cells (Tregs) or the induction of T-cell anergy (Larché, 2007, PubMed). By presenting specific T-cell epitopes without the IgE-binding components of the whole allergen, peptide therapies can potentially reduce the risk of systemic allergic reactions while effectively "re-training" the immune system (Circassia, 2016, Clinical Trials). Monitoring the efficacy of such interventions often involves measuring changes in HDM-specific IgE/IgG4 ratios and the frequency of pMHC-II tetramer-binding CD4+ T cells (Wambre et al., 2011, PubMed).

Other names

House dust mite allergen-HLA-II complexHDM peptide-MHC II complexHDM-specific pMHCIIHDM T-cell epitope-HLA complexHDM pMHC-TCR complex

Induction of T-cell tolerance through the presentation of T-cell epitopes, leading to Th2-to-Treg/Th1 immune deviation, T-cell anergy, or clonal deletion of allergen-specific CD4+ T cells (Larché, 2007, PubMed).