Methods: The recombinant proteins (CSR1-2, DMO) were expressed and purified for the serum screening test. Sera were obtained from Korean children with allergic symptoms who had positive soybean-specific IgE. The level of serum specific IgE was measured by the ImmunoCAP system (Phadia, Uppsala, Sweden) and considered as positive when they were 0.35 kU/L or higher. The allergenicity of purified-recombinant protein was evaluated by immunoblot analysis.
Results: Sera from 40 allergic patients sensitized to soybean (26 boys and 14 girls) were obtained. Their age ranged between 0 and 4 years (mean age 2.2 years). The soybean-specific IgE level of the patients was 26.8 kU/L on average. Most of the patients(27/40) were diagnosed with atopic dermatitis, while some of them had asthma (2/40), urticaria (2/40), or other allergic diseases (9/40). Serum screening test was done using patients’sera and newly inserted protein in GM soybean. CSR1-2 and DMO from GM soybean had an apparent molecular weight of 64 kDa and 39.8 kDa, respectively. The immunoblot analysis showed positive IgE reactivity between patients' sera and proteins from traditional soybeans. However, CSR1-2 and DMO did not show any reactivity.
Conclusion: Our results suggest that novel proteins (CSR1-2, DMO) encoded by newly inserted gene in GM soybean are not likely to develop allergies.
Reference:1. Kim JH, Ahn K, Lee SI, Kim HY. Allergenicity assessment of insect-resistant genetically modified maize Bt11, MON810 and MON863. Food Sci Biotechnol 2009;18(5):1273-8
2. Lee SI, Kim JY, Han YS, Lee GS,Kim JH, Kim HY, Ahn K. : Assessment of Allergenicity in Genetically Modified Herbicide-Resistant Foods Using the Serum Screening Test, Pediatr. Allergy Respir. Dis(Korea) 2009;19(3):250-259