Biological Activity of Recombinant Der p 2, Der p 5 and Der p 7 Allergens of the House-Dust Mite <i>Dermatophagoides pteronyssinus</i>

Abstract

Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positiv-ities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Der p 2 and either Der p 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites.

Recombinant Allergens for Skin Testing

“…On the other hand, group 2 allergens including Der p 2 of D. pteronyssinus , Lep d 2 from Lepidoglyphus destructor, Der f 2 from D. farinae [94]and Tyr p 2 from Tyrophagus putrescentiae , have been evaluated in skin tests. Group 2 allergens, although not yet defined in terms of biological function, are recognized by the majority of the mite-sensitized allergics [95, 96, 97, 98, 99]. Unfortunately, group 5 and group 7 allergens could also not be assigned to a functional class of proteins with the exception of their ability to bind IgE from sensitized individuals [36].…”

“…Unfortunately, group 5 and group 7 allergens could also not be assigned to a functional class of proteins with the exception of their ability to bind IgE from sensitized individuals [36]. rDer p 5 and rDer p 7 from D. pteronyssinus and Blo t 5 from Blomia tropicalis have been confirmed to be able to elicit type 1 reactions in clinical studies [95, 96, 97, 98, 100, 101]. However, in view of the shared sequence homology, members of a distinct group of structurally related allergens can be expected to be cross-reactive as demonstrated in vitro for some of the mite allergens [102].…”

Production and Proteomic Characterization of Pharmaceutical-Grade <i>Dermatophagoides pteronyssinus </i>and <i>Dermatophagoides farinae </i>Extracts for Allergy Vaccines

“…allergens group 1 and 2 allergens seem to be the most important ones, as (i) they are recognized by ∼70–100% of HDM-sensitized patients [2,13,14,15,16,17,18,19,20,21,22,23]; (ii) they bind substantial amounts of anti-mite IgE (i.e. 30–40% each on average) in patients’ sera [15,19,20,21, 24]. A recent study demonstrated that a mixture of group 1, 2, 5, 7, 8 and 10 allergens binds an average of 76% of D. pteronyssinus -specific IgE [25].…”

Atopic Dermatitis-Like Skin Lesions Induced by Topical Application of Mite Antigens in NC/Nga Mice

“…More than 90% of patients with AD are positive for the IgE radioallergosorbent test (IgE-RAST) against mite Ag [9], and clinical symptoms of AD improved after mites had been removed [10, 11]. Dermatophagoides pteronyssinus (Dp), a representative allergen of human AD, is involved in the pathogenesis of AD [12]. Although mite Ag are major allergens in human AD, there is no suitable animal model for investigating the importance of mite Ag in AD.…”