title: Two newly identified cat allergens: the von Ebner gland protein Fel d 7 and the latherin-like protein Fel d 8.
abstract: BACKGROUND
  Characterization of the complete IgE binding spectrum of cat allergens is important for the development of improved diagnosis and effective immunotherapeutics. While Fel d 1 remains unchallenged as the major cat allergen, we now report the isolation of two new allergens capable of binding similar concentrations of IgE in the allergic sera of some individuals.
  
  
  METHODS
  Cat tongue and submandibular salivary gland cDNA libraries were screened by DNA hybridisation and IgE immunoassay. The isolated DNA fragments were sub-cloned into an E. coli expression system and the IgE reactivity was examined with human cat-allergic sera using a DELFIA IgE quantitation assay.
  
  
  RESULTS
  Fel d 7, an 18 kDa von Ebner gland protein Can f 1 homologue, was isolated from the tongue library. Fel d 8, a 24-kDa latherin-like protein with homology to Equ c 5, was isolated from the submandibular library. The frequency of IgE binding of cat-allergic sera to recombinant Fel d 1, 7 and 8 was 60.5, 37.6 and 19.3%, respectively. Inhibition studies indicated some IgE binding cross-reactivity between Fel d 7 and dog dander extracts.
  
  
  CONCLUSIONS
  The study reports the isolation and characterization of two new cat allergens. The isolation of these allergens provides the opportunity to determine the role that IgE binding proteins other than Fel d 1 play in cat-allergic disease. For cat-allergic individuals with moderate to mild rhinoconjunctivitis these allergens may play a more important role in the manifestation of their allergic disease.
authors.affiliation: Division of Molecular Biotechnology, Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Subiaco, WA, Australia. wendy@ichr.uwa.edu.au
authors.forename: W
authors.initials: W
authors.lastname: Smith
authors.forename: S E
authors.initials: SE
authors.lastname: O'Neil
authors.forename: B J
authors.initials: BJ
authors.lastname: Hales
authors.forename: T L Y
authors.initials: TL
authors.lastname: Chai
authors.forename: L A
authors.initials: LA
authors.lastname: Hazell
authors.forename: S
authors.initials: S
authors.lastname: Tanyaratsrisakul
authors.forename: S
authors.initials: S
authors.lastname: Piboonpocanum
authors.forename: W R
authors.initials: WR
authors.lastname: Thomas
mesh_terms: D000485:Allergens / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002415:Cats / Q000276:immunology*; D003001:Cloning, Molecular; D007073:Immunoglobulin E / Q000097:blood; D054835:Lipocalin 1 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012471:Salivary Proteins and Peptides / Q000276:immunology / Q000302:isolation & purification*; D016415:Sequence Alignment
chemical_list: D000485:Allergens; D054835:Lipocalin 1; D012471:Salivary Proteins and Peptides; D007073:Immunoglobulin E; D012313:RNA