中文摘要：

目的调节性T细胞（Treg）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（IDO）基因转染小鼠树突状细胞（DC）,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。方法采用慢病毒转染技术,将含人全长IDO基因转染到小鼠DC细胞,G418筛选获得IDO-DC细胞,同时设置空白对照组（DC细胞）及空质粒转染组（EGFP-DC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DC细胞,与小鼠T淋巴细胞共培养后,Treg细胞增殖明显,和EGFP-DC细胞（7.5%vs 3.6%,P〈0.05）及DC细胞（7.5%vs 3.1%,P〈0.05）相比差异显著。结论 IDO基因转染小鼠DC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。

英文摘要：

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 was to investigate the effects of mouse DC cell transfected with IDO gene on inducing the proliferation of Treg cell in vitro.Methods By using the recombinant lentiviral vector,the human IDO cDNA was transfected into mouse DC cell（IDO-DC） and co-culture with T lymphocytes from the peripheral blood of C57 mouse.The parental DC cells and DC cells transfected with blank plasmid pEGFP（EGFP-DC） 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 DC cell successfully and the IDO-DC cells could induce the proliferation of Treg cell.There was significantly difference between the IDO-DC cells and EGFP-DC cells（7.5%：3.6%,P0.05） and between the IDO-DC cells and DC cells（7.5%：3.1%,P0.05）.Conclusion Our results suggest that the DC 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.