Open AccessEvaluation of basophil activation caused by transgenic rice seeds expressing whole T cell epitopes of the major Japanese cedar pollen allergens
Author(s) -
Takaishi Shinya,
Saito Saburo,
Kamada Minori,
Otori Nobuyoshi,
Kojima Hiromi,
Ozawa Kenjiro,
Takaiwa Fumio
Publication year - 2019
Publication title -
clinical and translational allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.979
H-Index - 37
ISSN - 2045-7022
DOI - 10.1186/s13601-019-0249-8
Subject(s) - basophil activation , genetically modified rice , medicine , basophil , immunoglobulin e , immunology , allergy , oral immunotherapy , antigen , genetically modified crops , antibody , transgene , biology , biochemistry , gene
Background Japanese cedar (JC) pollinosis is a serious type I allergic disease in Japan. Although subcutaneous immunotherapy and sublingual immunotherapy have been applied to treat JC pollinosis, high doses of allergens may cause IgE‐mediated allergic reactions. The transgenic rice seeds that contain genetically modified Cry j 1 and Cry j 2, the two major allergens of JC pollen, have been developed as candidates for oral immunotherapy. Although the antigens in the transgenic rice seeds (Tg‐rice seeds) were engineered such that they decrease binding ability with IgE and they are of insufficient length to cross‐link IgE on the surface of mast cells or basophils, the safety of Tg‐rice seeds for patients with JC pollinosis was unclear. Methods To verify the safety of Tg‐rice seeds in terms of allergies, we investigated the percentage of activated basophils induced by Tg‐rice seed extract in the basophil activation test. Blood samples from 29 patients with JC pollinosis were collected. Tg‐rice seed extract, non‐transgenic wild‐type rice seed extract, and Cry j 1 and Cry j 2 were mixed with the blood with reagents. The percentage of activated basophils was assessed by CD203c expression, a basophil activation marker. Results The percentage of activated basophils after the stimulation with Tg‐rice seed extract was 4.5 ± 1.6% (mean ± SD) compared with 62.9 ± 20.2% after Cry j 1‐ and Cry j 2‐stimulation (difference 58.4%, P < 0.001, 95% confidence interval 51.0–65.9%). Conclusions The results will contribute to the safety of Tg‐rice seeds in terms of allergies.