中文摘要：

目的观察半成熟树突状细胞（smDCs）在小鼠胚胎干细胞（ESCs）来源的肝细胞移植中诱导免疫耐受的作用及机制，并分析smDCs与调节性树突状细胞（regDCs）之间的关系。方法将绿色荧光蛋白（GFP）标记的129系小鼠ESCs按前期方法向肝细胞诱导分化，同时诱导129系小鼠骨髓单核细胞向smDCs和regDCs分化。将smDCs、regDCs分别预先输入BALB／c小鼠体内，3d后再将ESCs分化的肝细胞移植入BALB／e小鼠肝实质内。观察移植细胞生存时间、生长状况、局部免疫反应情况；检测分析受体血CD4＋T细胞Foxp3表达情况等。结果对照组小鼠肝实质内移植细胞仅生存1周，smDCs组与regDCs组生存时间可达4周，移植部位CD3＋T细胞浸润较对照组明显减轻；smDCs与regDCs在形态和表型方面相似，二者均中度表达MHC-11、CIMO、CD80、CD86；smDCs组受体小鼠外周血CD4＋T细胞Foxp3表达量明显升高由1．11％上升至5．38％；regDCs组Foxp3表达量亦有所升高达3．87％。结论smDCs能诱导ESCs源性肝细胞移植耐受，其机制可能与Foxp3＋ Tregs产生相关。smDCs与regDCs作用类似，且均中度表达MHC．Ⅱ、CD40等，推测为同一类型的耐受性树突状细胞。

英文摘要：

Objective To investigate the inducing effect and mechanism of semimature dendritic cell （smDCs） on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cells （ESCs）, and to study the connections between smDCs and regulatory dendritic cells （regDCs）. Methods ESCs of 129 mouse labelled green fluorescent protein （GFP） were induced to hepatocytes by using previous methods. Meanwhile, bone marrow mononuclear cells of 129 mouse were induced to smDCs and regDCs. Moreover, the hepatocytes differentiated from 129 mouse ESCs were transplanted into liver of BALB/e mouse 3 days after infusing smDCs and regDCs suspension of 129 mouse into BALB/c mouse by tail vein respectively. After that, the growth status and survival time of transplanted cells in the recipient and infiltration of lymphocytes in transplant sites were observed. Furthermore, Foxp3 expression of peripheral blood CD4 ＋ T cells was also tested. Results In the control group, the transplanted cells in liver of BALB/c mouse survived only about 1 week. In contrast, the transplanted cells of smDC groups and regDCs groups survived about 4 weeks and the transplant sites of smDC groups also had less CD3 ＋ T cells. The morphology of smDCs were similar with regDCs. The expression of MHC-Ⅱ , CD40, CD80 and CD86 on smDCs and regDCs were moderate. Moreover, the Foxp3 expression of peripheral blood CD4 ＋ T cells in smDC groups was higher than that in the control groups, from 1.11% up to 5.38%. The Foxp3 expression in regDC groups rose to 3, 87%. Conclusion The smDCs could induce transplantation tolerance of hepatocytes differentiated from 129 mouse ESCs in the recipient. The mechanism was associated with high level of Foxp3 ＋ Tregs, which could be increased by means of smDCs appropriate expression of MHC-Ⅱ , CD4O, CD80 and CD86. The smDCs and regDCs were the same type of tolerance dendritic cells.