Expression of hypoallergenic Der f 2 derivatives with altered intramolecular disulphide bonds induces the formation of novel ER-derived protein bodies in transgenic rice seeds

• Published in: Journal of experimental botany Vol. 63; no. 8; pp. 2947 - 2959
• Main Authors: Yang, Lijun, Hirose, Sakiko, Suzuki, Kazuya, Hiroi, Takachika, Takaiwa, Fumio
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.05.2012
• Subjects: Agronomy. Soil science and plant productions; Allergens; Allergens - immunology; Allergies; Animals; Antibodies; Antigens, Dermatophagoides - immunology; Arthropod Proteins - immunology; Biological and medical sciences; Cytoplasmic Structures - immunology; Dermatophagoides pteronyssinus; Digestive enzymes; Disulfides - immunology; Endoplasmic Reticulum - metabolism; Endoplasmic Reticulum - ultrastructure; Endoplasmic Reticulum Stress; Endosperm; Endosperm - metabolism; Fundamental and applied biological sciences. Psychology; Genetic engineering applications; Genetic Vectors - genetics; Genetics and breeding of economic plants; Humans; Immune Tolerance - immunology; Immunoglobulin E - immunology; Mice; Oryza - genetics; Oryza - ultrastructure; Oryza sativa; Plant breeding: fundamental aspects and methodology; Plant physiology and development; Plants, Genetically Modified; Protein Transport; Proteins; RESEARCH PAPER; Research Papers; Rice; Seed Storage Proteins - metabolism; Seeds; Seeds - genetics; Solubility; Subcellular Fractions - metabolism; Transformation, Genetic; Transgenic plants; Vaccination; Monocotyledones; mite allergen; Vaccine; Cereal crop; Oryza sativa; Arachnida; Acari; Gramineae; Disulfide bond; Arthropoda; Seed; Angiospermae; Botany; immunotherapy; rice seed; Allergy vaccine; Spermatophyta; Endosperm; Transgenic plant; Invertebrata; Der f 2; Allergen; Protein body
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/ers006

House dust mites (HDM) are the most common source of indoor allergens and are associated with allergic diseases worldwide. To benefit allergic patients, safer and non-invasive mucosal routes of oral administration are considered to be the best alternative to conventional allergen-specific immunotherapy. In this study, transgenic rice was developed expressing derivatives of the major HDM allergen Der f 2 with reduced Der f 2-specific IgE reactivity by disrupting intramolecular disulphide bonds in Der f 2. These derivatives were produced specifically as secretory proteins in the endosperm tissue of seeds under the control of the endosperm-specific glutelinGluB-1promoter. Notably, modified Der f 2 derivatives aggregated in the endoplasmic reticulum (ER) lumen and were deposited in a unique protein body (PB)-like structure tentatively called the Der f 2 body. Der f 2 bodies were characterized by their intracellular localization and physico-chemical properties, and were distinct from ER-derived PBs (PB-Is) and protein storage vacuoles (PB-IIs). Unlike ER-derived organelles such as PB-Is, Der f 2 bodies were rapidly digested in simulated gastric fluid in a manner similar to that of PB-IIs. Oral administration in mice of transgenic rice seeds containing Der f 2 derivatives encapsulated in Der f 2 bodies suppressed Der f 2-specific IgE and IgG production compared with that in mice fed non-transgenic rice seeds, and the effect was dependent on the type of Der f 2 derivative expressed. These results suggest that engineered hypoallergenic Der f 2 derivatives expressed in the rice seed endosperm could serve as a basis for the development of viable strategies for the oral delivery of vaccines against HDM allergy.