Tissue localization of bovine dander allergen Bos d 2.
BACKGROUND
Domestic mammals are important sources of indoor allergens. However, the origin at the tissue level and the biologic function of mammalian allergens are largely unknown.


OBJECTIVE
The aim of this study was to localize the source of the major bovine dander allergen, Bos d 2, in bovine tissues.


METHODS
Samples from several organs were tested for the presence of mRNA encoding Bos d 2 and Bos d 2 protein by using the reverse transcriptase polymerase chain reaction and immunohistochemical staining, respectively.


RESULTS
Skin proved to be the only tissue where mRNA encoding Bos d 2 was detected. This observation was confirmed by immunohistochemistry with a monoclonal anti-Bos d 2 antibody as the primary antibody. In the skin sections, Bos d 2 was found in the secretory cells of apocrine sweat glands and the basement membranes of the epithelium and hair follicles. Bos d 2 belongs to the family of lipocalins comprising a number of pheromone carrier proteins that are present, for example, in the secretions of the apocrine sweat glands.


CONCLUSIONS
Together with earlier data, our findings suggest that Bos d 2 is produced in sweat glands and transported to the skin surface as a carrier of the pheromone ligand. Because dander allergens of a number of mammalian species are lipocalins, the common biologic function of being pheromone carriers seems to be a common feature of an important group of aeroallergens.
Rautiainen
J
J
Department of Clinical Microbiology, University of Kuopio, Finland.
Rytkönen
M
M
Syrjänen
K
K
Pentikäinen
J
J
Zeiler
T
T
Virtanen
T
T
Mäntyjärvi
R
R
D000485:Allergens / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D052179:Antigens, Plant; D002417:Cattle; D004848:Epithelium / Q000378:metabolism; D005260:Female; D018859:Hair Follicle / Q000378:metabolism; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008321:Mammary Glands, Animal / Q000378:metabolism; D010306:Parotid Gland / Q000378:metabolism; D010675:Pheromones / Q000276:immunology / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011506:Proteins; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D013361:Sublingual Gland / Q000378:metabolism; D013363:Submandibular Gland / Q000378:metabolism; D013545:Sweat Glands / Q000378:metabolism; D014059:Tongue / Q000378:metabolism; D001743:Urinary Bladder / Q000378:metabolism
D000485:Allergens; D052179:Antigens, Plant; C099745:BDA20 dander protein, Bos taurus; D010675:Pheromones; D011506:Proteins; D012333:RNA, Messenger