Sensitisation to the Lipid-Binding Apolipophorin Allergen Der p 14 and the Peptide Mag-1

Abstract

Background: The IgE-binding peptides Mag 1 and Mag 3 and the high-molecular-weight protein M-177 have been identified as parts of the apolipophorin-like group 14 house dust mite allergen. By analogy with the homologous insect proteins, apolipophorins are hydrophobic proteins found in lipid bodies and lipid transport particles. This explains why they degrade and are poorly represented in extracts. Methods: We have examined the T cell stimulation induced by a 341-residue recombinant Der p 14 peptide equivalent to the Mag 1 polypeptide examined by others. Results: Peripheral blood mononuclear cells from both allergic and non-allergic donors responded strongly in in vitro proliferation assays to the Der p 14 peptide to induce markedly more ³H-thymidine incorporation than Der p 2 and the release of Th2 cytokines. Conclusions: The apolipophorin-like group 14 allergens, despite their predicted hydrophobicity and lipid-binding activity, can induce high IgE responses and T cell stimulation. They appear to be important mite allergens unsuited to representation by aqueous extracts of mites.

Chemokine-Driven Regulation of Established Type 1 and Type 2 Cytokine Responses to Environmental Antigens

“…The issue of whether nonatopic subjects do not display allergic diseases because they are inherently nonresponsive under the conditions of environmental antigen exposure [10, 11]or if clinical tolerance reflects the success of mediated mechanisms that actively inhibit the development of type 2 immunity, as we believe, remains controversial and requires further investigation. Our evidence [12, 13]and that of others [14, 15, 16], argues that healthy nonatopic subjects exhibit substantial allergen-specific CD4 T cell-mediated cytokine responses directly ex vivo. This has led us to evaluate the role of chemokines in maintaining this putatively protective state.…”

The Role of the House Dust Mite-Induced Innate Immunity in Development of Allergic Response

“…Der p 7, contrary to Der p 2 or Der f 2, did not bind LPS but can interact with other lipids including polymyxin B. Consequently, Der p 7 could represent a carrier of bacterial lipopeptides to promote a Th2 response, through putative interactions with TLR2, the receptor of such bacterial ligands. Together with the data obtained with the group 2 and the lipid-binding group 13 and 14 mite allergens [69,70], lipid-binding properties could represent an important common feature of some HDM allergens. The association of natural lipidic adjuvants with these groups of mite allergens more likely facilitates the allergen sensitization process.The chitinase activity of group 15 and 18 mite allergens [71] could probably amplify the sensitization to HDM as mammalian chitinases or chitinase-like proteins, overproduced under a Th2-bias environment (IL-4, IL-13), may play a key role in the allergic inflammation [72,73].…”

Varying Allergen Composition and Content Affects the in vivo Allergenic Activity of Commercial <b><i>Dermatophagoides pteronyssinus</i></b> Extracts

“…The recombinant allergens rDer p 5, 7, 10 and 21 were expressed in the vector pET 17b as nonfusion proteins [ [5,25,26 ]and Casset and Vrtala, unpubl.]. rDer p 2 was expressed in the vector pET 17b with a C-terminal hexahistidine tag [27] and an rDer p 14 fragment (aa 1–260) was expressed in the vector pET 19b with an N-terminal hexahistidine tag [28]. rDer p 8 was expressed in the vector pGEX as a GST fusion protein and rDer p 20 in the vector pET 19b as a nonfusion protein [Thomas et al, unpubl.].…”