Identification of the major water/salt insoluble wheat proteins involved in cereal hypersensitivity

Authors

  • C. P. SANDIFORD,

    1. Department of Occupational and Environmental Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London and
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    • Department of Paediatrics and Neonatal Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.

  • A. S. TATHAM,

    1. IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol, UK
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  • R. FIDO,

    1. IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol, UK
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  • J. A. WELCH,

    1. Department of Occupational and Environmental Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London and
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  • M. G. JONES,

    1. Department of Occupational and Environmental Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London and
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  • R. D. TEE,

    1. Department of Occupational and Environmental Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London and
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  • P. R. SHEWRY,

    1. IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol, UK
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  • A. J. NEWMAN TAYLOR

    1. Department of Occupational and Environmental Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London and
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Summary

Background Several studies have investigated water/salt soluble proteins which comprise 50% of the proteins in wheat. The remaining 50% of wheat proteins, are water/salt insoluble proteins of which there is limited information on their role in cereal hypersensitivity.

Objectives To investigate the allergenicity of the water/salt insoluble gliadin and glutenin proteins (prolamins).

Methods RAST, electrophoresis and Western blotting were used to identify water/salt insoluble wheat allergens. Competitive RAST inhibition was conducted to investigate cross-reactivity between prolamins and water/salt soluble wheat proteins.

Results Specific IgE to α-gliadin and to total glutenins were detected in all sera. IgE to β-, γ-, fast ω-, and slow ω-gliadin were present in lower numbers of sera. Prolamin allergens of 90–11 kDa were identified by immunoblotting. Water/salt soluble proteins crossreacted with a-gliadin and total glutenins.

Conclusions Individuals who are hypersensitive to water/salt soluble wheat proteins produce specific IgE to water/salt insoluble wheat proteins. Western blotting has shown that gliadins, glutenins and proteins with similar molecular weights as the endogenous water/salt soluble wheat enzyme inhibitors are important allergens. Alpha and fast ω- are the most allergenic gliadins. The water/salt insoluble proteins share cross-reacting epitopes with water/salt soluble proteins. These data show that the numbers of proteins involved in the development of cereal hypersensitivity is greater than previously believed and that the development of specific IgE to α-gliadin may in part depend on the presence of cross-reacting antibodies to water/salt soluble flour allergens.

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