House dust mite allergens

House dust is the trigger of the allergic reaction in > 50% of all allergy patients. Since the 60s of the last century it is known that house dust mites are the actual allergens in house dust.

The most important currently known allergens of Dermatophagoides farinae, Dermatophagoides pteronyssinus and Dermatophagoides microceras (varies according to http://allergen.org)

Dermatophagoides farinae (American house dust mite)

• The f 1 cysteine protease (IgE reactivity 60-100%)
• The f 2 lipid-binding protein (IgE reactivity 60-100%)
• The f 3 trypsin
• The f 6 chymotrypsin
• The f 7 (unknown)
• The f 10 Tropomyosin
• The f 11 paramyosin
• The f 13 fatty acid-binding protein
• The f 14 lipid transfer protein (Apolipophorin)
• The f 15 Chitinase
• The f 16 Gelsolin/Villin
• The f 17 calcium-binding protein
• The f 18 chitin-binding protein
• The f 22 (unknown: 14 molecular weight ?)
• The f 24 ubiquinone-cytochrome C reductase - binding protein (homologous)
• The f 25 triose phosphatisomerase
• The f 26 Myosin alkali light chain
• The f 27 Serpin
• The f 28 Heat Shock Protein
• The f 29 cyclophilin
• The f 30 Ferritin
• The f 31 Cofilin
• The f 33 alpha-tubulin

Dermatophagoides microceras (house dust mite)

• The m 1 cysteine protease

Dermatophagoides pteronyssinus (European house dust mite)

• The p 1 cysteine protease (IgE reactivity 60-100%)
• The p 2 lipid-binding protein (IgE reactivity 60-100%)
• The p 3 trypsin
• The p 4 alpha-amylase
• The p 5 (unknown)
• The p 6 chymotrypsin
• The p 7 (unknown)
• The p 8 glutathione S-transferase
• The p 10 tropomyosin
• The p 14 lipid transfer protein (Apolipophorin)
• The p 15 chitinase
• The p 18 chitin-binding protein
• The p 20 arginine kinase
• The p 21 (unnamed: 14 Molecular weight kDa)
• The p 23 peritrophin-like protein domain
• The p 24 ubiquinone -cytochrome -C- reductase-binding protein

Allergens with protease activity: Allergens of the groups 1,3,6 and 9 all have protease activity. These proteases are formed in the mite as inactive precursors and are activated by the cysteine protease (Der p 1, Der f 1). In the bronchial epithelium, these proteases (above all the cysteine protease Der p 1) are able to damage the barrier of the bronchial epithelium, so that the allergens can get in contact with the dendritic cells and thereby induce an immunological cascade.

Der p 1 and Der p 2 are the major allergens of D. pterynissinus. 80-90% of house dust mite allergy sufferers are sensitive to these allergens. Der p 23 has a sensitization rate of about 70%.

Allergens with lipid-binding structural regions: these include the groups 2,5,7,13,14.

Muscle proteins: these include groups 10 and 11. Only about 10 of the mite allergy sufferers react to p 10. The protein structure of tropomyosin is strongly conserved. This results in a high cross-reactivity to the tropomyosins of crustaceans and shellfish (food allergens).

Chitin-binding proteins: Allergens of the groups 15, 18, 23 show a homology in the groups 15, 18 and 23.