26-Week oral safety study in macaques for transgenic rice containing major human T-cell epitope peptides from Japanese cedar pollen allergens.

A study of repeated oral administration of transgenic rice containing a hybrid peptide of major human T-cell epitopes (7Crp) from Japanese cedar pollen allergens was carried out in cynomolgus macaques over 26 weeks. The monkeys were divided into three groups, each comprising three males and three females, administered a high dose of transgenic rice, a low dose of transgenic rice, or a high dose of the parental rice strain. The transgenic rice 7crp#10 and the parental nontransgenic control were polished, steamed, mashed, and prepared in water at 40% (w/v). Monkeys were orally administered a high or low dose of transgenic rice or the nontransgenic control by gavage every day. No adverse effects on general behavior or body weight of animals were observed during the study. Analysis of blood from monkeys administered for 26 weeks showed that, with few exceptions, there were no significant differences in hematological or biochemical values between them. Additionally, neither pathological symptoms nor histopathological abnormalities were observed. Thus, it was concluded that oral administration of transgenic rice containing T-cell epitopes from Japanese cedar pollen allergens has no adverse effects.