Molecular and Immunological Characterization of a Wheat Serine Proteinase Inhibitor as a Novel Allergen in Baker's Asthma
| Autor: | Josef Thalhamer, Angelika Stoecklinger, Rudolf Valenta, Alisher Touraev, Monika Grote, Claudia Constantin, Santiago Quirce, Adriano Mari, Erwin Heberle-Bors, Ines Swoboda |
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| Rok vydání: | 2008 |
| Předmět: |
Adult
Male Serine Proteinase Inhibitors Molecular Sequence Data Immunology Wheat flour Wheat Hypersensitivity Basophil Biology medicine.disease_cause Immunoglobulin E law.invention Allergen immune system diseases Food allergy law Complementary DNA medicine Humans Immunology and Allergy Amino Acid Sequence Microscopy Immunoelectron Phylogeny Triticum Gene Library Base Sequence food and beverages Allergens Middle Aged medicine.disease Asthma respiratory tract diseases Occupational Diseases medicine.anatomical_structure Biochemistry Seeds Recombinant DNA biology.protein Female Sequence Alignment |
| Zdroj: | The Journal of Immunology. 180:7451-7460 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | IgE-mediated sensitization to wheat flour belongs to the most frequent causes of occupational asthma. A cDNA library from wheat seeds was constructed and screened with serum IgE from baker's asthma patients. One IgE-reactive phage clone contained a full-length cDNA coding for an allergen with a molecular mass of 9.9 kDa and an isoelectric point of 6. According to sequence analysis it represents a member of the potato inhibitor I family, a group of serine proteinase inhibitors, and thus is the first allergen belonging to the group 6 pathogenesis-related proteins. The recombinant wheat seed proteinase inhibitor was expressed in Escherichia coli and purified to homogeneity. According to circular dichroism analysis, it represented a soluble and folded protein with high thermal stability containing mainly β-sheets, random coils, and an α-helical element. The recombinant allergen showed allergenic activity in basophil histamine release assays and reacted specifically with IgE from 3 of 22 baker's asthma patients, but not with IgE from grass pollen allergic patients or patients suffering from food allergy to wheat. Allergen-specific Abs were raised to localize the allergen by immunogold electron microscopy in the starchy endosperm and the aleuron layer. The allergen is mainly expressed in mature wheat seeds and, despite an ∼50% sequence identity, showed no relevant cross-reactivity with allergens from other plant-derived food sources such as maize, rice, beans, or potatoes. Recombinant wheat serine proteinase inhibitor, when used in combination with other specific allergens, may be useful for the diagnosis and therapy of IgE-mediated baker's asthma. |
| Databáze: | OpenAIRE |
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