title: IgE-mediated anaphylaxis caused by bites of the pigeon tick Argas reflexus: cloning and expression of the major allergen Arg r 1.
abstract: BACKGROUND
  Anaphylactic reactions caused by bites of the European pigeon tick Argas reflexus are repeatedly reported. This soft-backed tick is a parasite of wild pigeons colonizing urban buildings and houses. Occasionally the ticks can bite human beings, inducing anaphylactic reactions in sensitized patients.
  
  
  OBJECTIVE
  Our aim was to characterize the major allergen implicated in a series of anaphylactic reactions caused by Argas bites and to produce the allergen as recombinant protein for diagnostic purposes.
  
  
  METHODS
  Protein extracts were prepared from whole A reflexus bodies, and IgE immunoblots were performed with sera from 13 patients who had an anaphylactic reaction with pigeon tick bites. A cDNA expression library was constructed from whole ticks and screened with a polyclonal rabbit antiserum raised against the major allergen.
  
  
  RESULTS
  The cDNA coding for the dominant allergen Arg r 1 could be isolated. It encodes a protein belonging to the lipocalin family. Allergenicity of the recombinant Arg r 1 was confirmed by immunoblot, ELISA, and intradermal skin tests.
  
  
  CONCLUSIONS
  The dominant allergen of A reflexus has been isolated and the corresponding cDNA cloned. The recombinant protein, a lipocalin, was expressed in Escherichia coli and was shown to be immunoreactive in vitro and in vivo. Recombinant Arg r 1 was used as a diagnostic tool in a series of anaphylactic reactions caused by pigeon tick bites.
authors.affiliation: Centre de Recherche Public-Santé/Centre Hospitalier de Luxembourg, Laboratory of Immunogenetics and Allergology, Luxembourg. christiane.hilger@crp-sante.lu
authors.forename: Christiane
authors.initials: C
authors.lastname: Hilger
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Bessot
authors.forename: Nicolas
authors.initials: N
authors.lastname: Hutt
authors.forename: Fabienne
authors.initials: F
authors.lastname: Grigioni
authors.forename: Frédéric
authors.initials: F
authors.lastname: De Blay
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Pauli
authors.forename: François
authors.initials: F
authors.lastname: Hentges
mesh_terms: D000485:Allergens / Q000276:immunology / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000707:Anaphylaxis / Q000209:etiology*; D000818:Animals; D026864:Argas / Q000235:genetics / Q000276:immunology*; D001733:Bites and Stings / Q000150:complications*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D015723:Gene Library; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology*; D017385:Sequence Homology
chemical_list: D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E