IDO基因转染小鼠Lewis肺癌细胞体外诱导Treg细胞增殖的研究

目的 调节性T细胞(regulatory T cell,Treg cell)在肿瘤局部免疫耐受中发挥了重要作用,但其产生机制尚不清楚.本实验通过将吲哚胺-2,3-双加氧酶(indoleamine-2,3-dioxygenase,IDO)基因转染小鼠Lewis肺癌细胞,体外研究对Treg细胞的诱导增殖作用,为肺癌免疫耐受产生机制研究提供新的依据.方法 采用阳离子脂质体Lipofectmine2000,将含人全长IDO基因的pEGFP-IDO真核表达质粒转染到小鼠Lewis肺癌细胞,G418筛选获得Lewis-IDO细胞,同时设置空白对照组(Lewis细胞)及空质粒转染组(Lewis-EGFP细胞),将3种细胞分别与小鼠T淋巴细胞混合培养,利用流式细胞技术分析3种细胞对Treg细胞的诱导增殖作用.结果 IDO基因成功转染到小鼠Lewis细胞,与小鼠T淋巴细胞共培养后,Treg细胞增殖明显,和Lewis-EGFP细胞(6.2%:4.9%,P＜0.05)及Lewis细胞(6.2%:5.0%,P＜0.05)相比差异有统计学意义.结论 IDO基因转染小鼠Lewis肺癌细胞在体外能明显增强Treg细胞的增殖,为肺癌局部免疫耐受机制研究提供了新的实验依据.

In vitro proliferation of regulatory T cell induced by mouse Lewis lung cancer cell transfected with IDO gene

Objective Regulatory T(Treg) cells play the important role in the immune tolerance of cancer.But the mechanism is still not clear.The aim of this study is to investigate the effects of mouse Lewis lung cancer cell transfected with IDO gene on inducing the proliferation of Treg cell in vitro.Methods By using the cationic liposome Lipofectamine 2000,the eukaryotic expression plasmid vectors carrying human IDO cDNA was transfected into mouse Lewis lung cancer cell line(Lewis-IDO) and co-culture with lymphocytes from the peripheral blood of C57 mouse.The parental Lewis cells and Lewis cells transfected with blank plasmid pEGFP(Lewis-EGFP) was used as control groups.After culture,the Treg cells were sorted using fluorescence-activated cell sorting(FACS).Results The IDO gene was transfected into Lewis cell successfully and the Lewis-IDO cells could induce the proliferation of Treg cell.There was significantly difference between the Lewis-IDO cells and Lewis-EGFP cells(6.2%:4.9%,P<0.05) and between the Lewis-IDO cells and Lewis cells(6.2%:5.0%,P<0.05).Conclusion Our results suggest that the Lewis cells transfected with IDO gene can induce the proliferation of Treg cell in vitro,which will be of benefit to the research of cancer immune tolerance.