title: Recombinant allergens promote expression of aminopeptidase-n (CD13) on basophils in allergic patients.
abstract: IgE-dependent activation of basophils is associated with upregulation of several surface molecules. We recently identified the surface enzyme aminopeptidase N (CD13) as a novel activation antigen on human basophils. In the present study, we asked whether CD13 can be employed as a novel marker of allergen-induced activation of basophils in allergic individuals. Patients allergic to major allergens from grass pollen (Phl p 1, Phl p 5), birch pollen (Bet v 1), or house dust mites (Der p 2), were examined. Blood basophils were exposed to various concentrations of recombinant allergens for 15 minutes, and examined for expression of CD13 by multicolor flow cytometry. The allergen-induced upregulation of CD13 was compared with allergen-dependent increases in expression of CD63 and CD203c. Exposure to recombinant allergens resulted in an increase in expression of CD13 on basophils in all sensitized individuals, whereas no increase in CD13 was seen in healthy controls. The effects of the recombinant allergens on CD13-expression were dose- and time-dependent, were not observed in the absence of extracellular calcium, and were counteracted by preincubation of basophils with the PI3-kinase-targeting drugs staurosporin and LY294002. There was a good correlation between allergen-induced upregulation of CD13, CD63, and CD203c on basophils. In aggregate, our data show that recombinant allergens promote expression of CD13 on basophils in sensitized individuals. The functional significance and diagnostic implications of this observation remain to be determined.
authors.affiliation: Department of Internal Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Sonneck
authors.forename: C
authors.initials: C
authors.lastname: Baumgartner
authors.forename: L
authors.initials: L
authors.lastname: Rebuzzi
authors.forename: K
authors.initials: K
authors.lastname: Marth
authors.forename: K W
authors.initials: KW
authors.lastname: Chen
authors.forename: A W
authors.initials: AW
authors.lastname: Hauswirth
authors.forename: S
authors.initials: S
authors.lastname: Florian
authors.forename: S
authors.initials: S
authors.lastname: Vrtala
authors.forename: H J
authors.initials: HJ
authors.lastname: Bühring
authors.forename: R
authors.initials: R
authors.lastname: Valenta
authors.forename: P
authors.initials: P
authors.lastname: Valent
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology*; D015703:Antigens, CD / Q000097:blood; D001491:Basophils / Q000201:enzymology / Q000276:immunology* / Q000502:physiology; D018826:CD13 Antigens / Q000097:blood*; D002118:Calcium / Q000502:physiology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007377:Interleukin-3 / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D010727:Phosphoric Diester Hydrolases / Q000097:blood; D010980:Platelet Membrane Glycoproteins; D011755:Pyrophosphatases / Q000097:blood; D011994:Recombinant Proteins / Q000276:immunology; D060149:Tetraspanin 30
chemical_list: D000485:Allergens; D015703:Antigens, CD; C554586:CD63 protein, human; C427944:ENPP3 protein, human; D007377:Interleukin-3; D010980:Platelet Membrane Glycoproteins; D011994:Recombinant Proteins; D060149:Tetraspanin 30; D019869:Phosphatidylinositol 3-Kinases; D010727:Phosphoric Diester Hydrolases; D018826:CD13 Antigens; D011755:Pyrophosphatases; D002118:Calcium