中文摘要：

目的：观察人脐带间充质干细胞（hUC-MSC）在小鼠体内的迁移变化以及宿主的免疫反应。方法：45只BALB/c小鼠分为模型组、移植组和对照组,各15只。模型组和移植组小鼠建立肠炎模型;移植组和对照组小鼠每只移植入1×106个DiI标记的hUC-MSC。运用活体成像技术观察hUC-MSC在小鼠体内的存活和迁移情况;移植第5天,荧光显微镜观察hUC-MSC在移植组和对照组小鼠结肠中的分布;第20天应用流式细胞术检测各组小鼠体内T细胞亚群的变化。结果：hUC-MSC细胞移植后,最先迁移到小鼠的肺部。其在移植组小鼠体内大部分聚集在腹部,逐渐到达有炎症的肠道,第7天时聚集的细胞最多;在对照组小鼠体内散在分布。移植第5天移植组小鼠结肠组织中可见到hUC-MSC细胞。对照组、模型组和移植组小鼠CD3＋CD4＋T细胞的百分数为（36.01±5.25）%、（48.39±10.15）%和（35.50±0.98）%,CD3＋CD8＋T细胞的百分数为（16.89±3.48）%、（10.76±4.23）%和（13.10±3.29）%,CD4＋CD8＋T细胞的百分数为（2.15±0.17）%、（4.69±2.22）%和（2.83±0.73）%,3组间比较,差异均有统计学意义（F=31.726、25.124和83.234,P均〈0.05）,模型组CD3＋CD4＋及CD4＋CD8＋T细胞比例高于对照组（P〈0.05）,移植组与对照组的T细胞亚群数量相近（P〉0.05）。结论：hUC-MSC可迅速迁移到炎症组织并诱导宿主免疫耐受,将成为细胞治疗的重要来源。

英文摘要：

Aim：To observe in immunocompetent colitc mice model whether human umbilical cord-derived mesenchymal stem cell（hUC-MSC） could survive in vivo and make effect.Methods：A total of 45 BALB/c mice were allocated into model group,transplanted group,and control group.Each group had fifteen mice.Colitis model was established in model and transplanted groups.hUC-MSCs（1×106） with DiI lablled were injected into transplanted and control groups.In vivo imaging technique was used to observe distribution of the cells transplanted in colon on the 5th day.Flow cytometry was used to detect T cell subpopulations in each group on the 20th day.Results：The cells moved to the lung of mice after transplantation,and then to intestinal gradually.The cells in transplanted group collected in belly,while scattered in control group.The expression rate of CD3＋CD4＋,CD3＋CD8＋,CD4＋CD8＋T cells were（36.01±5.25）%,（16.89±3.48）%,and（2.15±0.17）%in control group,（48.39±10.15）%,（10.76±4.23）%,and（4.69±2.22）%in modle group,and（35.50±0.98）%,（13.10±3.29）%,（2.83±0.73）%in transplanted group,there were obvious differences（F=31.762,25.124,and 83.234,P0.05）.Conclusion：hUC-MSCs are prone to immigrate to the inflammatory tissues quickly and induce host immune tolerance.