Studies on the effect of genetically modified foods on oral tolerance

本研究旨在调查转基因大豆对小鼠口服耐受性的影响，转基因大豆似乎在预防食物过敏中起着重要作用。在卵白蛋白（OVA）免疫前和免疫后的适当时间内，每天口服大豆，在免疫前5天，每天1次喂食卵白蛋白（OVA）作为抗原，诱导口服耐受。3周后，采用酶联免疫吸附法（ELISA）检测脾脏细胞抗ova IgG的产生和对抗原的增殖反应，同时检测细胞中[^3H]-氨基的摄入量。Th1反应包括抗ova IgG2a和IFN-g的产生，Th2反应包括抗ova IgG1和IL-10。结果表明，转基因大豆对口服OVA引起的淋巴样细胞增殖的下调无影响，但能有效抑制抗OVA IgG、IgG2a、IgG1抗体的产生以及脾细胞IFN-g和IL-10的分泌。这些结果表明，至少在我们的研究中使用的转基因大豆似乎并不能预防食物过敏。

The present study was undertaken to investigate the effect of genetically modified soybeans on oral tolerance in mice that appeared to play an important role in the prevention of food allergy. The soybeans were daily given orally over an appropriate period before and after immunization of OVA and oral tolerance was induced by feeding ovalbumin(OVA) as an antigen once a day for five days before immunization with the antigen. Then 3 weeks later anti-OVA IgG production and proliferative responses of spleen cells to the antigen were determined by ELISA and intake of[^3H]-mymidine in the cells. Th1 responses including anti-OVA IgG2a and IFN-g production and Th2 responses including anti-OVA IgG1 and IL-10 were also measured. The results showed that administration of the genetically modified soybeans was followed by no effects on the dowregulation of proliferation of lymphoid cells caused by oral OVA but was effective in facilitating the suppression of anti-OVA IgG,IgG2a,IgG1 antibody production as well as IFN-g and IL-10 secretion from splenic cells. These results suggest that genetically modified soybeans used in our studies, at least, does not appear to prevent food allergy.