Generation of transgenic rice with reduced content of major and novel high molecular weight allergens

Yuko Ogo,Yuhya Wakasa,Fumio Takaiwa,Tsukasa Matsuda,Atsuo Urisu,Kana Hirano

doi:10.1186/s12284-014-0019-0

Yuko Ogo, Yuhya Wakasa + Show 4 more

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https://doi.org/10.1186/s12284-014-0019-0

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Abstract

BackgroundRice seed proteins contain antigens that provoke allergic responses in some individuals with food allergy, particularly in those with cereal allergy, and these antigens can elicit clinical symptoms such as eczema and dermatitis. We previously generated transgenic rice with reduced accumulation of the three major allergens, which dramatically reduced the level of IgE binding from patients’ sera. However, the transgenic rice still possesses allergenic reactivity. Recently, two globulin-like proteins were identified as candidates of novel high molecular weight (HMW) IgE-binding proteins that cause rice allergy.ResultsWe identified a glucosidase family encoded by four genes as novel HMW rice allergens based on IgE antibody reactivity from individuals with allergy to rice. To further reduce allergenicity, we generated transgenic rice with reduced accumulation of these HMW allergens. We crossed the rice with reduced HMW allergens and with reduced major allergens, and all major and HMW allergens were substantially reduced in the progeny of the crossed rice. Allergen suppression did not significantly alter accumulation patterns of seed storage proteins and protein folding enzymes. The sera of a portion of patients showed low IgE-binding to the crossed line, suggesting that the crossed line is effective for a portion of patients who are allergic to proteins other than major allergens.ConclusionsThe transgenic rice with reduced levels of all major and HMW allergens is thought to be an option for a portion of allergy patients with hypersensitive responses to various kinds of rice allergens.Electronic supplementary materialThe online version of this article (doi:10.1186/s12284-014-0019-0) contains supplementary material, which is available to authorized users.

Highlights

Rice seed proteins contain antigens that provoke allergic responses in some individuals with food allergy, in those with cereal allergy, and these antigens can elicit clinical symptoms such as eczema and dermatitis
Two serum specimens including serum 2 showed lower IgE-binding to Major x high molecular weight (HMW) lines than to the lines with reduced contents of the major allergens, while the others showed IgE binding to Major x HMW lines almost to the Major lines or tended to give even slightly high IgE-binding (Figure 5). These results suggested that Major x HMW rice is effective for a portion of the patients who are allergic to proteins other than major allergens, it may not be effective for the other patients
Seed characteristics in rice lines with reduced levels of the major and HMW allergens We investigated the accumulation of seed storage proteins in mature seeds

Summary

Introduction

Rice seed proteins contain antigens that provoke allergic responses in some individuals with food allergy, in those with cereal allergy, and these antigens can elicit clinical symptoms such as eczema and dermatitis. Α-globulin (26 kDa), β-glyoxalase I (33 kDa), and α-amylase/trypsin inhibitor (14–16 kDa) were identified as major rice allergens based on recognition by IgE from individuals with food allergy (Alvarez et al, 1995; Limas et al, 1990; Usui et al, 2001; Matsuda et al., 2006). The 14–16 kDa α-amylase/trypsin inhibitors constitute a multigene family, whereas the 26 and 33 kDa allergens are encoded by single-copy genes. These allergens strongly react with IgE antibody in sera from many individuals with rice allergy, and caused eczematous and atopic dermatitis (Urisu et al, 1991)

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