Dermatophagoides farinae allergen 2 (Der f 2)

Dermatophagoides farinae allergen 2 (Der f 2) is a major protein allergen produced by the American house dust mite, Dermatophagoides farinae (UniProt: P14171). It belongs to the Niemann-Pick type C2 (NPC2) family and functions as a lipid-binding protein, which may enhance its allergenicity by facilitating interactions with the innate immune system, specifically through the MD-2/TLR4 signaling complex (PMID: 25617481). Der f 2 is highly clinically significant, as it is recognized by IgE antibodies in the majority of mite-allergic individuals, playing a central role in the development of allergic asthma, rhinitis, and atopic dermatitis (WHO/IUIS Allergen Nomenclature). In therapeutic development, Der f 2 is a primary target for allergen-specific immunotherapy (AIT), where it is used in standardized extracts like Odactra to induce immunological tolerance (FDA). The treatment aims to shift the patient's immune profile from a Th2-mediated allergic response to a regulatory state characterized by the production of IgG4 blocking antibodies and the activation of regulatory T cells (PMID: 11544150). Consequently, Der f 2 serves as both a diagnostic marker for mite sensitivity and a critical active component in desensitization therapies.

Other names

Der f IIMajor mite allergen Der f 2NPC2-like proteinMite group 2 allergen

Allergen-specific immunotherapy (AIT) utilizing Der f 2 aims to induce peripheral T-cell tolerance and promote the production of protective IgG4 antibodies. This process involves the modulation of the immune system from a Th2-biased response to a Th1 or Treg-dominated response, thereby reducing the release of inflammatory mediators from mast cells and basophils upon subsequent allergen exposure (PMID: 11544150).