Monoclonal IgE antibodies against birch pollen allergens: novel tools for biological characterization and standardization of allergens.
BACKGROUND
IgE antibodies are key players in immediate hypersensitivity reactions. Allergen characterization and standardization is usually based on the sera of allergic patients, whereas monoclonal IgE antibodies specific for clinically relevant allergens are very rare.


OBJECTIVE
The aim of this study was to establish IgE mAbs specific for birch pollen allergens, because these are important inhalant allergens.


METHODS
IgE-producing hybridomas were identified by using the highly sensitive rat basophilic leukemia cell mediator release assay with enhanced allergen stimulation by additional cross-linking with birch pollen-specific IgG antibodies. The obtained IgE mAbs were characterized by immunologic methods and by cDNA sequencing.


RESULTS
Seven IgE mAbs specific for the birch pollen allergens Bet v 1 or Bet v 6 were obtained and were all biologically active in mast cell-based assays. Mediator release experiments with mAb combinations indicated that 2 different epitope regions were recognized on Bet v 1, whereas the 2 Bet v 6-specific mAbs bound to the same epitope region. After sensitization of rat basophilic leukemia cells with IgE mAbs, different amounts of Bet v 1 or Bet v 6 were detected in commercial diagnostic allergen reagents, whereas sensitization with polyclonal IgE resulted in similar allergenic potency of all products.


CONCLUSIONS
IgE mAbs represent promising novel tools for allergen characterization and component-resolved standardization of allergen extracts.
Kaul
Susanne
S
Division of Allergology, Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, D-63225 Langen, Germany.
Scheurer
Stephan
S
Danz
Nicole
N
Schicktanz
Simone
S
Vieths
Stefan
S
Hoffmann
Andreas
A
D000485:Allergens / Q000737:chemistry / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology*; D000918:Antibody Specificity; D052179:Antigens, Plant; D001491:Basophils / Q000276:immunology; D029662:Betula / Q000276:immunology*; D015550:Cell Degranulation; D002457:Cell Extracts / Q000592:standards; D000939:Epitopes / Q000276:immunology; D006825:Hybridomas; D007073:Immunoglobulin E / Q000737:chemistry / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000032:analysis; D007147:Immunoglobulin Light Chains / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology; D011058:Pollen / Q000276:immunology*; D051381:Rats; D014407:Tumor Cells, Cultured
D000485:Allergens; D000911:Antibodies, Monoclonal; D052179:Antigens, Plant; D002457:Cell Extracts; D000939:Epitopes; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula; D007073:Immunoglobulin E