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