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Laminin γ‐1 and collagen α‐1 ( VI ) chain are galactose‐α‐1,3‐galactose–bound allergens in beef
Author(s) -
Takahashi H.,
Chinuki Y.,
Tanaka A.,
Morita E.
Publication year - 2014
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/all.12302
Subject(s) - immunoglobulin e , chemistry , immunoassay , food allergy , allergy , antibody , sensitization , biochemistry , immunology , microbiology and biotechnology , medicine , biology
Background Sensitization to the carbohydrate galactose‐α‐1,3‐galactose (α‐Gal) has been reported in patients with beef allergy. However, the proteins responsible for this allergy have not yet been identified. This study aimed to identify beef proteins that predominantly react with serum IgE in Japanese patients with beef allergy. Methods Sera were collected from 29 patients with beef allergy who had allergic reaction(s) such as urticaria, abdominal pain, vomiting, and anaphylactic shock after ingestion of beef and pork; the sera tested positive for IgE against beef and pork. IgE‐binding proteins were detected by immunoblotting sera from the patients and identified using a combination of two‐dimensional gel electrophoresis and peptide mass fingerprinting techniques. The involvement of carbohydrate in the binding of IgE to allergens was examined by periodate treatment and an inhibition assay with cetuximab by immunoblotting. Specific IgE binding to cetuximab was measured using the CAP ‐fluorescent enzyme immunoassay. Results Two IgE‐binding proteins (240 kD a and 140 kD a) were detected in beef extract and identified as laminin γ‐1 and the collagen α‐1 (VI) chain from B os taurus , respectively. Periodate treatment or the inhibition assay resulted in the loss of IgE binding to these proteins. Immunoblotting with anti‐α‐Gal antibody revealed the presence of α‐Gal on the 240‐ and 140‐ kD a beef proteins. The amount of IgE bound to cetuximab was significantly correlated with that to beef in the patients with beef allergy. Conclusion The carbohydrate moiety (α‐Gal) on laminin γ‐1 and collagen α‐1 ( VI ) chain are possibly common IgE‐reactive proteins in the Japanese patients with beef allergy.