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Immunologic analysis of monoclonal and immunoglobulin E antibody epitopes on natural and recombinant Amb a 1
Author(s) -
Wopfner N.,
Bauer R.,
Thalhamer J.,
Ferreira F.,
Chapman M.
Publication year - 2008
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/j.1365-2222.2007.02872.x
Subject(s) - ragweed , monoclonal antibody , immunoglobulin e , recombinant dna , antibody , epitope , allergen , immunology , monoclonal , biology , microbiology and biotechnology , allergy , virology , biochemistry , gene
Summary Background Amb a 1 is the major allergen from ragweed pollen and more than 90% of ragweed‐allergic patients react with this protein. Although Amb a 1 was cloned and sequenced in 1991, little is known of the specificity of anti‐Amb a 1 antibodies or of the immunologic properties of the recombinant allergen. Objective To compare binding of monoclonal antibodies (mAb) and IgE antibodies to purified natural Amb a 1 (nAmb a 1) and recombinant Amb a 1 (rAmb a 1). Methods Binding of a panel of anti‐Amb a 1 mAb and IgE antibodies to nAmb a 1 or rAmb a 1 was compared by immunoblotting. Chimeric ELISA was used to measure specific IgE to these allergens using 89 ragweed‐allergic sera from Austria, Italy, Canada and the United States. Results The 8 mAb bound to a 38 kDa Amb a 1 band in ragweed pollen extract and a subset of 5 mAb also bound to the 26 kDa chain of nAmb a 1. A two‐site ELISA was developed using a mAb pair, which was ∼10‐fold more sensitive to rAmb a 1. There was a significant correlation between IgE antibody binding to nAmb a 1 and rAmb a 1 ( n =89, r =0.79, P <0.001). A subset of ∼40% of patients showed greater reactivity to nAmb a 1 than to rAmb a 1. Conclusions The data suggest that there is less reactivity of human IgE to rAmb a 1 compared with nAmb a 1. The development of more sensitive, quantitative ELISA for Amb a 1 will require the production of new mAb especially directed against nAmb a 1.