Molecular characterization of wheat allergens specifically recognized by patients suffering from wheat-induced respiratory allergy.

Abstract

BACKGROUND:

Wheat (Triticum aestivum) is an important allergen source responsible for various clinical manifestations of allergy (i.e. food allergy, pollen allergy, respiratory allergy to flour-Baker's asthma).

OBJECTIVE:

The objective of this study was the molecular and immunological characterization of new recombinant wheat allergens and to evaluate their usefulness for the diagnosis of allergy to wheat.

METHODS:

A T. aestivum cDNA library was constructed and screened with serum IgE from patients suffering from wheat allergy to identify cDNAs coding for new wheat allergens. The allergen-encoding cDNAs were expressed in Escherichia coli and purified to homogeneity. IgE reactivity of recombinant proteins was analysed in RAST-based, non-denaturing dot blot experiments and by ELISA with sera from wheat allergic patients and their allergenic activity was assessed in basophil degranulation experiments.

RESULTS:

We report the molecular characterization, recombinant expression and purification of five wheat allergens, a thioredoxin h isoform, glutathione transferase, 1-Cys-peroxiredoxin, profilin and dehydrin. Homologous proteins were identified by sequence comparisons in various plants. 1-Cys-peroxiredoxin appeared to be the most relevant of the newly identified wheat allergens according to prevalence of IgE recognition and results from basophil degranulation experiments. It showed IgE cross-reactivity with seed proteins from barley, rye, rice, maize, soy, oat and spelt. 1-Cys-peroxiredoxin, glutathione transferase and dehydrin were mainly recognized by patients with baker's asthma but not wheat-induced food allergy.

CONCLUSION AND CLINICAL RELEVANCE:

The characterized recombinant wheat allergens may be useful for the development of serological tests which allow the discrimination of different clinical manifestations of wheat allergy.

• Authors: S Pahr, C Constantin, A Mari, S Scheiblhofer, J Thalhamer, C Ebner, S Vrtala, I Mittermann, R Valenta
• Journal: Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology (Clin Exp Allergy) Vol. 42 Issue 4 Pg. 597-609 (Apr 2012) ISSN: 1365-2222 [Electronic] England
• PMID: 22417217 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Blackwell Publishing Ltd.

Chemical References

• Allergens
• Plant Proteins
• Recombinant Proteins
• Immunoglobulin E

Topics

• Adult
• Allergens (chemistry, immunology, isolation & purification)
• Amino Acid Sequence
• Asthma (immunology)
• Cell Degranulation (immunology)
• Cross Reactions
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoblotting
• Immunoglobulin E
• Male
• Middle Aged
• Molecular Sequence Data
• Plant Proteins (chemistry, immunology, isolation & purification)
• Recombinant Proteins (chemistry, immunology)
• Reverse Transcriptase Polymerase Chain Reaction
• Wheat Hypersensitivity (immunology)
• Young Adult