Yonsei Med J.  2006 Aug;47(4):505-512. 10.3349/ymj.2006.47.4.505.

Evaluating the Allergic Risk of Genetically Modified Soybean

• Kim SH
• Kim HM
• Ye YM
• Kim SH
• Nahm DH
• Park HS
• Ryu SR
• Lee BO

• KMID: 1779500
• DOI: http://doi.org/10.3349/ymj.2006.47.4.505

Abstract

Genetically modified (GM) soybean (carrying the EPSPS transgene) is the most common GM food in Korea. In order to assess whether genetic modification increases the allergenic risk of soybeans, the allergenicity and IgE-reactive components of wild-type and GM soybean extracts were compared in allergic adults who had been sensitized to soybeans. We enrolled 1,716 adult allergy patients and 40 healthy, non-atopic controls. Skin prick tests and IgE enzyme linked immunosorbent assays (ELISAs) were performed using wild-type and GM soybean extracts, along with other common inhaled allergens. The specificities of serum IgE antibodies from allergic patients and the identities of the IgE-reactive components of the soybean extracts were compared using ELISA inhibition testing, 2-dimensional gel electrophoresis, and IgE immunoblotting. To evaluate the effects of digestive enzymes and heat treatment, the soybean extracts were heated or pre- incubated with or without simulated gastric and intestinal fluids. The IgE sensitization rates to wild-type and GM soybeans were identical (3.8% of allergic adults), and circulating IgE antibodies specific for the two extracts were comparable. The results of the ELISA inhibition test, SDS-PAGE, and IgE immunoblotting showed a similar composition of IgE-binding components within the wild-type and GM extracts, which was confirmed using two-dimensional gel electrophoresis, IgE immunoblotting, and amino acid sequencing. None of the subjects had a positive response to purified EPSPS protein in the skin prick test, ELISA, or IgE immunoblot analysis. These findings suggest that the IgE sensitization rate to GM soybean extracts is identical to that of wild-type soybean extracts in adult allergy patients. In addition, based on both in vivo and in vitro methods, the allergenicity of wild type and GM soybean extracts was identical.

Keyword

Soybean; genetically modified; allergic risk

MeSH Terms

Soybeans/*immunology
Skin Tests
Protein Structure, Tertiary
*Plants, Genetically Modified
Middle Aged
Immunoglobulin E/blood/chemistry
Immunoblotting
Humans
Food Hypersensitivity/etiology/*immunology
Food/*adverse effects
Enzyme-Linked Immunosorbent Assay
Electrophoresis, Gel, Two-Dimensional
*Crops, Agricultural
Allergens/*immunology
Adult
Adolescent

Figure

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  Fig. 1 Ten percent SDS-PAGE (A) and IgG immunoblot analysis (B) of wild-type (W) and GM (G) soybean extracts, and EPSPS (E) protein. Samples were incubated without (1, 3) or with β-mercaptoethanol (2, 4).

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  Fig. 2 Soybean-specific serum IgE binding to both wild-type (open circles) and GM (closed circles) extracts by ELISA according to wild-type soybean skin reactivity. Horizontal bars indicate mean values.

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  Fig. 3 IgE ELISA inhibition results for wild-type (A) and GM (B) soybean-coated wells with the serial addition of EPSPS protein, wild-type soybean extract, or GM soybean extract. Significant inhibition was noted for both wild-type and GM soybean extracts, while no significant inhibition was noted with D. pteronyssinus and EPSPS protein.

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  Fig. 4 IgE immunoblot analysis of EPSPS protein (E), wild-type (W) and GM (G) soybean extracts using sera from the sensitized patients (1-14), non-atopic controls (C), anti-EPSPS antibody (15), and buffer control (B). Wild-type: Daewon soybean, GM: Roundup Ready® soybean (GTS 40- 3-2).

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  Fig. 5 Two-dimensional gel electrophoresis (A) and IgE immunoblot (B) of wild-type and GM soybean extracts.

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