Fumio Takaiwa

Rice Seed-Based Allergy Vaccines: Induction of Allergen-Specific Oral Tolerance Against Cedar Pollen and House Dust Mite Allergies

Japanese cedar pollen and house dust mite allergens are major causes of immunoglobulin (Ig)E-mediated type I allergy. For these allergies allergen-specific immunotherapy using systemic immunization with crude allergen extracts has been achieved as an only curative treatment. Here, we introduce a novel allergen-specific immunotherapy using rice seed-based oral vaccines comprising genetically modified hypoallergenic tolerogen or T-cell epitope peptides derived from allergens as a desirable alternative.

Transgenic Rice for Mucosal Vaccine and Immunotherapy

The use of recombinant allergen–based immunotherapy has improved current practical approaches to allergy treatment and has revealed potential new clinical strategies for the control of allergic diseases. Oral immunotherapy using a rice-based oral vaccine is one attractive strategy that was shown to be effective for the control of pollen allergies. When the peptides for a T cell specific to Japanese cedar (Cryptomeria japonica) pollen are expressed by transgenic rice seeds and orally administered to naive mice, it induced oral tolerance responsible for the inhibition of the IgE-mediated allergic response, suppression of histamine production, and reduction of clinical symptoms (e.g., sneezing), thereby preventing the development of this pollen-induced allergy. The results may have important implications for the development of peptide-based mucosal vaccines and for immunotherapy to control allergic diseases. The potential of transgenic rice as a new mucosal vaccine-delivery vehicle for the control of allergies is reviewed from the perspective of future directions for the development of clinically effective allergy vaccines.