House dust mite group 1 and 2 allergens (HDM Group 1/2)

House dust mite (HDM) group 1 and 2 allergens are the primary proteins responsible for sensitizing and triggering allergic reactions in individuals worldwide (UniProt P08176, P49278). Group 1 allergens (e.g., Der p 1, Der f 1) are cysteine proteases that facilitate their own uptake by cleaving tight junction proteins in the respiratory epithelium, thereby increasing mucosal permeability (PMID: 10485830). Group 2 allergens (e.g., Der p 2, Der f 2) mimic the human MD-2 protein to activate the Toll-like receptor 4 (TLR4) signaling pathway, promoting Th2-biased inflammation even in the absence of other microbial signals (PMID: 26453170). These allergens are the central targets of allergen-specific immunotherapy (AIT), which aims to induce immunological tolerance through controlled, repeated exposure. AIT shifts the immune response from a Th2-dominated profile to a regulatory T cell (Treg) and Th1 response, leading to the production of protective IgG4 "blocking" antibodies (PMID: 25108385). Clinically, standardized extracts containing these allergens, such as Odactra and Acarizax, are used to treat HDM-induced allergic rhinitis and allergic asthma (FDA Odactra Label).

Other names

Der p 1Der f 1Der p 2Der f 2Dermatophagoides pteronyssinus allergensDermatophagoides farinae allergensMite group 1 and 2 allergens

Allergen-specific immunotherapy (AIT) involves the repeated administration of these allergens to induce peripheral T-cell tolerance. This process promotes the expansion of regulatory T cells (Tregs) and the production of allergen-specific IgG4 "blocking" antibodies, which compete with IgE for allergen binding and inhibit mast cell degranulation (PMID: 25108385).