title: Characterization of the dog lipocalin allergen Can f 6: the role in cross-reactivity with cat and horse.
abstract: BACKGROUND
  Allergy to the domestic dog (Canis familiaris) affects 5-10% of the population in affluent countries. Three of four patients are allergic to more than one pet, which can only partially be explained by cross-reactivity between serum albumins. The lipocalin protein family harbours allergens in mammalian species.
  
  
  METHODS
  We set out to clone and characterize a novel dog allergen, and investigate its potential role in cross-sensitization between dog, cat and horse. The gene encoding Can f 6 was amplified from dog skin and bladder cDNA libraries. The corresponding allergen was produced and purified by recombinant techniques and evaluated by SDS-PAGE, size exclusion chromatography, circular dichroism spectra, ELISA and basophil activation test.
  
  
  RESULTS
  IgE antibodies to Can f 6 were found in serum from 38% of dog-sensitized subjects. Sequence similarities between the lipocalin allergens Can f 6, Fel d 4 (cat) and Equ c 1 (horse) suggested a probability for cross-reactivity, which was demonstrated by competitive ELISA. The biological relevance of Can f 6 was confirmed by basophil activation test in dog-allergic patients.
  
  
  CONCLUSIONS
  Can f 6 is a new lipocalin dog allergen that cross-reacts with lipocalins from horse and cat. Can f 6 and homologous allergens may contribute to multisensitization and symptoms in individuals allergic to mammals.
authors.affiliation: Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska Institutet, Stockholm, Sweden.
authors.forename: O B
authors.initials: OB
authors.lastname: Nilsson
authors.forename: J
authors.initials: J
authors.lastname: Binnmyr
authors.forename: A
authors.initials: A
authors.lastname: Zoltowska
authors.forename: T
authors.initials: T
authors.lastname: Saarne
authors.forename: M
authors.initials: M
authors.lastname: van Hage
authors.forename: H
authors.initials: H
authors.lastname: Grönlund
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D015549:Basophil Degranulation Test; D002415:Cats; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004285:Dogs; D005260:Female; D015723:Gene Library; D006736:Horses; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007223:Infant; D054834:Lipocalins / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D055815:Young Adult
chemical_list: D000485:Allergens; D054834:Lipocalins