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

Carcinopodacarus polymorphus gen. n. et sp. n. (Acariformes: Dermationidae: Dermationinae) is described from the guira cuckoo Guira guira (Gmelin) (Cuculiformes: Cuculidae) in Brazil. The new genus differs from the closest genus, Psittophagoides Fain, 1964, by the following features: in both sexes, the anterior spines of trochanters I and II are absent (vs present in Psittophagoides), setae d2 are distinctly developed (vs only alveoli), and genual setae mGI are absent (vs present); in males, the hysteronotal shield is split transversally at the level of trochanters III (vs hysteronotal shield entire); in females, the platelets situated posterior to the propodonotal shield are absent (vs present), the metapodosomal sclerites are present (vs absent), and the adanal shields are fused anteriorly to each other (vs separated from each other). In this species, andropolymorphism is detected for the first time for the family. It involves various characters but the most impressive feature is the structure of legs III. In hetero- and mesomorphic males, these legs are strongly hypertrophied and have a distinct ventral spur on femora III; in homeomorphic males, legs III are not modified and subequal to legs IV.

• Klíčová slova
• kukačky, polymorfismus, andropolymorfismus,
• MeSH
• ptáci * parazitologie   MeSH
• Pyroglyphidae * anatomie a histologie   ultrastruktura   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Brazílie MeSH