Identification and characterization of maize-specific pollen allergens

Abstract

Background: Zea mays (maize, corn) is worldwide the most grown crop. Maize pollen is known to be of high allergenicity; however there are few reports about maize pollen allergy. Maize pollen allergy has been discussed as cross-allergy to other poaceae. Clinically relevant specific maize pollen allergens have not been reported yet. Our aim was to identify and characterize specific maize pollen allergens. Methods: A maize pollen pJuFo cDNA phage display library was created and screened for IgE binding to maize pollen proteins with pooled sera from patients suffering from inhalative maize pollen allergy using the phage display technique. Fished cDNA clones were identified by sequence analysis. Recombinant proteins were expressed in E. coli. Sera of 8 workers occupationally exposed to maize pollen were screened with ELISA to determine type I-sensitization to the recombinant maize pollen proteins. Results: Fished cDNA clones coded 16 potential maize pollen allergens; 4 of them were further analyzed. One belongs to the already characterized maize allergen family profilin, another 3 were identified to be novel maize allergens from the families cytochrome c oxidase copper chaperone, 14-3-3-like proteins and endothelial differentiation-relating factor.. Serum IgE antibodies to each recombinant allergen were found in up to 3 of the 8 maize workers. Conclusions: There is evidence that maize pollen has a relevant allergenicity. 2 of the 4 maize pollen allergens we found (14-3-3-like proteins and endothelial differentiation-relating factor) belong to protein families which have not been described as allergens before. We conclude that beyond its cross-reactivity to other poaceae maize pollen is also a specific allergen.