BACKGROUND: The house dust mite (HDM) allergen Der p 18 belongs to the glycoside hydrolase family 18 chitinases. The relevance of Der p 18 for house dust mite allergic patients has only been partly investigated. OBJECTIVE: To perform a detailed characterization of Der p 18 on a molecular, structural and immunological level. METHODS: Der p 18 was expressed in E. coli, purified to homogeneity, tested for chitin-binding activity and its secondary structure was analyzed by circular dichroism. Der p 18-specific IgG antibodies were produced in rabbits to localize the allergen in mites using immunogold electron microscopy and to search for cross-reactive allergens in other allergen sources (i.e. mites, crustacea, mollusca and insects). IgE reactivity of rDer p 18 was tested with sera from clinically well characterized HDM-allergic patients (n = 98) and its allergenic activity was analyzed in basophil activation experiments. RESULTS: Recombinant Der p 18 was expressed and purified as a folded, biologically active protein. It shows weak chitin-binding activity and partial cross-reactivity with Der f 18 from D. farinae but not with proteins from the other tested allergen sources. The allergen was mainly localized in the peritrophic matrix of the HDM gut and to a lower extent in fecal pellets. Der p 18 reacted with IgE from 10% of mite allergic patients from Austria and showed allergenic activity when tested for basophil activation in Der p 18-sensitized patients. CONCLUSION: Der p 18 is a rather genus-specific minor allergen with weak chitin-binding activity but exhibits allergenic activity and therefore should be included in diagnostic test panels for HDM allergy.

• MeSH
• antigeny roztočů domácího prachu chemie   genetika   imunologie   MeSH
• antisérum chemie   MeSH
• bazofily cytologie   účinky léků   imunologie   MeSH
• chitin chemie   imunologie   MeSH
• Escherichia coli genetika   metabolismus   MeSH
• exprese genu MeSH
• interakční proteinové domény a motivy MeSH
• klonování DNA MeSH
• konformace proteinů, alfa-helix MeSH
• konformace proteinů, beta-řetězec MeSH
• králíci MeSH
• lidé MeSH
• proteiny členovců chemie   genetika   imunologie   MeSH
• protilátky krev   chemie   izolace a purifikace   MeSH
• Pyroglyphidae chemie   ultrastruktura   MeSH
• rekombinantní proteiny chemie   genetika   imunologie   MeSH
• respirační alergie chemicky indukované   imunologie   patofyziologie   MeSH
• sbalování proteinů MeSH
• sekvence aminokyselin MeSH
• sekvenční homologie aminokyselin MeSH
• sekvenční seřazení MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

House dust mites (HDMs) belong to the most potent indoor allergen sources worldwide and are associated with allergic manifestations in the respiratory tract and the skin. Here we studied the importance of the high-molecular-weight group 11 allergen from Dermatophagoides pteronyssinus (Der p 11) in HDM allergy. Sequence analysis showed that Der p 11 has high homology to paramyosins from mites, ticks, and other invertebrates. A synthetic gene coding for Der p 11 was expressed in Escherichia coli and rDer p 11 purified to homogeneity as folded, alpha-helical protein as determined by circular dichroism spectroscopy. Using antibodies raised against rDer p 11 and immunogold electron microscopy, the allergen was localized in the muscle beneath the skin of mite bodies but not in feces. IgE reactivity of rDer p 11 was tested with sera from HDM-allergic patients from Europe and Africa in radioallergosorbent test-based dot-blot assays. Interestingly, we found that Der p 11 is a major allergen for patients suffering from atopic dermatitis (AD), whereas it is only a minor allergen for patients suffering from respiratory forms of HDM allergy. Thus, rDer p 11 might be a useful serological marker allergen for the identification of a subgroup of HDM-allergic patients suffering from HDM-associated AD.

• MeSH
• antigeny roztočů domácího prachu chemie   genetika   imunologie   MeSH
• atopická dermatitida epidemiologie   imunologie   MeSH
• biologické markery MeSH
• cirkulární dichroismus MeSH
• Dermatophagoides pteronyssinus genetika   imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• imunoglobulin E krev   imunologie   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• molekulární sekvence - údaje MeSH
• proteiny členovců MeSH
• protilátky krev   imunologie   MeSH
• sekundární struktura proteinů MeSH
• sekvence aminokyselin MeSH
• séroepidemiologické studie MeSH
• tropomyosin chemie   genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVE: Expression of the gene encoding Der-p2 allergen-like protein in the castor bean tick Ixodes ricinus is induced by blood intake. Tick Der-p2 allergen-like protein belongs to a diverse family of ML proteins that includes major allergens of house dust mites, human MD-2 or similar proteins from Drosophila melanogaster. In ticks, genes encoding proteins belonging to the ML protein family were identified, but their protein products have not been characterized yet. METHODS: A gene encoding tick Der-p2 allergen-like protein was amplified from cDNA of engorged I. ricinus female using the gene-specific primers designed on a basis of partial sequences of related allergen-like genes. The tissue and state specific patterns of expression of the gene were analysed. The IgE binding activity of the produced recombinant protein was studied by use of ELISA. RESULTS: Analysis of the expression pattern showed that the gene encoding the tick Der-p2 allergen-like protein is strongly induced by the bloodmeal in gut and haemolymph throughout all tick developmental stages. Der-p2 allergen-like protein possesses a putative lipid-binding site, according to the comparisons with the related proteins. The ability of tick Der-p2 allergen-like protein to bind immunoglobulin E (IgE) was revealed. DISCUSSION: The presence of a putative lipid-binding domain in Der-p2 allergen-like protein and its ability to interact with IgE might indicate the involvement of the protein in the tick's immune response.

• MeSH
• alergeny chemie   genetika   imunologie   metabolismus   MeSH
• antigeny roztočů domácího prachu chemie   genetika   imunologie   metabolismus   MeSH
• Dermatophagoides pteronyssinus imunologie   MeSH
• imunoglobulin E imunologie   metabolismus   MeSH
• klíště genetika   růst a vývoj   imunologie   metabolismus   MeSH
• larva růst a vývoj   imunologie   MeSH
• lymfocytární antigen 96 chemie   imunologie   MeSH
• molekulární modely MeSH
• nymfa růst a vývoj   imunologie   MeSH
• rekombinantní proteiny chemie   genetika   imunologie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH