Dog saliva - a source of dog allergens

Abstract

Background:Allergy to dog (Canis famili-aris) is recognized worldwide, and it maygive rise to childhood asthma. Can f 1 andCan f 2 together with dog albumin (Can f3) are known allergens in canine. Dog dan-der extract is a poor diagnostic tool ofIgE-mediated allergy to dog. Despite beinga major allergen, Can f 1 is not a verydominant allergen and is therefore insuffi-cient for diagnosis of dog allergy. Theoverall aim of the project is to obtainimproved tools for diagnosis of dog allergyby characterizing and evaluating dog salivaas a new allergen source.Methods:Dog saliva was collected from 14different dog breeds. IgE binding to a dogsaliva pool and to dog dander proteins wascompared in immunoblot using sera from13 dog sensitized patients (SPT and Immu-noCAP positive to dog dander extract)either individually or as a pool. IgE bind-ing proteins present in the dog saliva poolwere identified by MALDI-TOF analysisof trypsin in-gel digested protein spotsafter 2D PAGE). The allergenic potentialof different dog breeds was analyzed inimmunoblot using the pool of dog positivesera.Results:In dog dander extract most of thepatients recognized protein bands that cor-responded to already described dog aller-gens (Can f 1, Can f 2 and albumin),whereas in the dog saliva pool at least 12IgE binding proteins could be detectedwith molecular weights ranging from 14 to67 kDa. MALDI-TOF analysis of IgEbinding dander proteins showed the pres-ence of Can f 1 and Can f 2. One addi-tional IgE binding protein could bedetected in dog saliva (Can f 1, Can f 2and parotid secretory protein). Differentprotein/allergen profiles could be noted insaliva taken from different dog breeds. E.g. in saliva from Golden Retriever, fewer IgEbinding bands were detected than in salivasamples taken from other dog breeds.Conclusion:It seems to be a greater abun-dance and diversity of IgE binding proteinsin dog saliva compared to dog danderextract. Thus, usage of dog saliva could bean important improvement in the diagnosisof dog allergy.