House dust mite peptide-MHC class II complex (HDM pMHCII)

House dust mite (HDM) peptide-MHC class II complexes are molecular assemblies consisting of proteolytic fragments from HDM allergens (e.g., Der p 1, Der p 2) bound to the peptide-binding groove of Major Histocompatibility Complex (MHC) class II molecules (Wambre et al., 2017). These complexes are presented on the surface of professional antigen-presenting cells, such as dendritic cells, where they are specifically recognized by the T-cell receptors (TCRs) of CD4+ T lymphocytes (Seumois et al., 2016). In allergic individuals, this recognition triggers the activation and expansion of Th2-polarized cells, which orchestrate the inflammatory cascade in conditions like allergic asthma and rhinitis (Akdis & Akdis, 2014). Therapeutic strategies targeting these complexes, such as allergen-specific immunotherapy (AIT) and peptide-based vaccines, aim to reprogram the immune system toward tolerance by inducing T-cell anergy or promoting the expansion of regulatory T cells (Tregs) (Larché, 2007). Monitoring these complexes using pMHCII tetramers serves as a critical tool for quantifying allergen-specific T-cell responses and assessing the efficacy of immunotherapies in clinical settings.

Other names

HDM-pMHCII complexDermatophagoides pteronyssinus peptide-HLA class II complexHDM allergen-MHC II complexHouse dust mite–derived peptide–MHC class II complexes recognized by CD4+ T-cell receptors

Induction of immune tolerance through T-cell anergy, deletion, or the induction of regulatory T cells (Tregs) that suppress Th2-mediated allergic inflammation (Akdis & Akdis, 2014).