转Bt玉米暴露对亲代及子代大鼠免疫细胞分型及细胞因子的影响

为研究转苏云金芽胞杆菌(Bacillus thuringiensis,Bt)基因抗虫玉米长期食用对大鼠免疫的影响,以其亲本非转基因玉米饲料及商业饲料为对照,分别采用流式细胞术及液相芯片法检测喂养90 d后亲代及子代刚断乳大鼠外周血、脾脏免疫细胞分型及相关血清细胞因子的表达。结果发现,转Bt基因抗虫玉米饲料组亲代大鼠外周血和脾脏及子代脾脏各淋巴细胞亚群(CD4~+、CD8~+、TCRαβ~+、TCRγδ~+)的细胞数量比例及亲代血清中10种细胞因子表达水平均与非转基因玉米饲料组无显著差异(P0.05);子代外周血B淋巴细胞数量比例显著增高,巨噬细胞炎症蛋白-1α、单核细胞趋化因子-1β、白细胞介素-5表达水平明显降低(P0.05)。结果表明:转Bt基因抗虫玉米暴露90 d对亲代大鼠免疫系统影响不大;对子代刚断乳大鼠的细胞免疫及体液免疫有一定的影响。

Effects of Parental Exposure to Genetically Modified Bt Maize on Immune Cell Phenotypes and Cytokines in Parental Rats and Weaning Offspring

In order to evaluate the effects of chronic exposure to genetically modified (GM) maize expressing Bacillusthuringiensis (Bt) toxins on immunity in rats, flow cytometry and liquid chip method were applied to detect immune cellphenotypes in the peripheral blood and spleen and the expression levels of related cytokines in the serum of parental ratsand newly weaning offsprings. Feeds with non-transgenic maize or commercial maize were used as control in this study. Ascompared to the control maize, Bt maize did not induced any alteration in the percentage of T and B cells and CD4+, CD8+,TCR αβ+, and TCR γδ+ subpopulations either in blood and spleen of parental rats or in the spleen of weaning offspring.No significant difference in the expression levels of cytokines (IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IFN-γ, TNF-α,MCP-1β, and MIP-1α) in the serum of parental rats was observed between the Bt and parental control maize groups (P > 0.05).However, the percentage of peripheral B cells was raised significantly, while the expression levels of MIP-1α, MCP-1β andIL-5 were significantly decreased in the peripheral blood of weaning offspring (P < 0.05). These results suggest long-termconsumption of genetically modified maize does not affect the immune system of parental rats, but may exert some influenceon cellular and humoral immunity in weaning offspring.