Dactylis glomerata pollen allergen (Dac g)

Dactylis glomerata pollen allergens are a group of clinically significant proteins derived from the pollen of Orchard grass (also known as Cocksfoot), which are major triggers of seasonal allergic diseases worldwide. These allergens, classified into several groups such as Dac g 1 (a beta-expansin) and Dac g 5 (a ribonuclease-like protein), are recognized by the immune system of sensitized individuals, leading to the cross-linking of IgE antibodies on mast cells and basophils [1][2]. This interaction triggers the release of inflammatory mediators like histamine, resulting in symptoms of allergic rhinitis, conjunctivitis, and bronchial asthma [3]. In a therapeutic context, these allergens serve as the active components in allergen-specific immunotherapy (AIT), where they are used to desensitize the patient's immune system [4]. By administering controlled doses of Dactylis glomerata extracts, AIT aims to induce long-term immunological tolerance, reducing the severity of allergic reactions upon subsequent natural exposure to the pollen [5]. Sources: [1] WHO/IUIS Allergen Nomenclature Sub-Committee; [2] UniProt (P13447); [3] PubMed (PMID: 15634330); [4] Journal of Allergy and Clinical Immunology (AIT Guidelines); [5] EAACI Position Papers.

Other names

Orchard grass pollen allergenCocksfoot grass pollen allergenDac g 1Dac g 2Dac g 3Dac g 4Dac g 5

Allergen-specific immunotherapy (AIT) induces immune tolerance by promoting the expansion of regulatory T cells (Tregs) and B cells, shifting the immune response from a Th2-biased profile to a Th1-biased profile, and stimulating the production of allergen-specific IgG4 blocking antibodies that prevent IgE-mediated mast cell degranulation.