Development of rice-seed based oral allergy vaccines containing hypoallergenic Japanese cedar pollen allergen derivatives for immunotherapy

Allergen-specific immunotherapy is only available curative treatment for IgE-mediated allergen diseases. Hypoallergenic allergen derivative with safety and high efficiency is required as tolerogen to induce immune tolerance to the causing allergens. In this study,　to generate rice-based oral allergy vaccine for Japanese cedar (JC) pollinosis, tertiary structure of major JC pollen allergens, Cry j 1 and Cry j 2, were more completely　destructed by shuffling than the previous ones without losing immunogenicity and then were specifically expressed in the endosperm of transgenic rice seed. They accumulated at high levels and were deposited in endoplasmic reticulum (ER) and ER derived protein bodies (PBs). Low allergenicity of these deconstructed Cry j 1 and Cry j 2 was evaluated by examining their binding activities to the specific IgE and basophil granule degradation test.