Researchers identify new allergen from short ragweed pollen

Investigators have identified a new allergen from short ragweed pollen that holds major diagnostic and therapeutic interest, according to research presented at the European Academy of Allergy and Clinical Immunology annual congress in Copenhagen, Denmark.

Researchers performed gel electrophoresis and IgE-immunoblots from 92 ragweed pollen-allergic donors. IgE-binding proteins were identified by mass spectrometry (MS) and molecular biology approaches, including PCR cloning and ragweed pollen transcriptome analysis.

“IgE-immunoblotting indicated that over 54% of tested ragweed pollen-allergic patients have IgE directed toward a so far undescribed 36-kDa protein, thus established as a major allergen,” the researchers reported.

Gene cloning and extensive immunological and MS characterization of natural and recombinant forms expressed in E. coli or tobacco plants determined that the allergen consisted of a 262-amino acid protein related to papain. A strong structural homology with cysteine proteases known as allergens, such as house dust mite-derived allergen Der p 1, was revealed through molecular modeling.

“We identified a previously undescribed major allergen from short ragweed pollen,” the researchers concluded. “This allergen was officially recognized as Amb a 11 [GenBank KF528831], by the World Health Organization and International Union of Immunological Societies Allergen Nomenclature Subcommittee. Because of its involvement in the IgE sensitization of most ragweed-allergic patients, and given its homology with cysteine proteases known to represent clinically important allergens, we conclude that Amb a 11 is of great diagnostic and therapeutic value.”

For more information:

Nony E. #13. Presented at: European Academy of Allergy and Clinical Immunology annual congress 2014; June 7-11; Copenhagen, Denmark.

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