中文摘要：

目的 探讨输注慢病毒载体介导的鼠基因工程调节性T淋巴细胞（Treg细胞）对小鼠异基因骨髓移植后移植物抗宿主病（GVHD）的影响。方法利用慢病毒载体介导，将鼠叉状头螺旋转录因子（Foxp3）基因转导人Balb／c小鼠的CD4＋CD25T淋巴细胞，即为基因工程Treg细胞。以Balb／c小鼠为供者，C57BL／6小鼠为受者，进行异基因骨髓移植，实验分4组进行：（1）工程Treg组经受鼠尾静脉输注供鼠骨髓细胞5×10^6个＋脾细胞5×10^6个＋基因工程Treg细胞5×10^6个；（2）移植对照组经受鼠尾静脉输注供鼠骨髓细胞5×10^6个＋脾细胞5×10^6个；（3）单纯照射组经受鼠尾静脉输注RPMI1640培养液0．2ml；（4）空载体对照组经受鼠尾静脉输注供鼠骨髓细胞5×10^6个＋脾细胞5×10^6个＋空载体转导的CD4＋CD25T淋巴细胞5×10^6个。每天观察受鼠存活情况；记录GVHD的发生情况；各组均于小鼠濒死前取其肝脏、小肠、皮肤等组织，进行病理学观察；取长期存活（超过60d）的受鼠骨髓细胞，检测嵌合情况。结果单纯照射组、移植对照组、工程Treg组和空载体对照组小鼠存活时间分别为（8．8±0．6）d、（36．7±2．5）d、（51．6±4．0）d和（34．1±2．3）d，工程Treg组小鼠存活时间明显长于其他各组，差异有统计学意义（P＜0．05）。移植对照组及空载体对照组小鼠肝脏、皮肤和小肠病理切片均存在GVHD病理改变，工程Treg组长期存活小鼠的肝脏、皮肤和小肠常规病理切片结构基本正常，未见GVHD病理表现，该组GVHD评分明显低于移植对照组及空载体对照组。结论小鼠异基因骨髓移植时联合输注基因工程Treg细胞可有效减少GVHD的发生，减轻其严重程度。

英文摘要：

Objective To explore the influence of the lentiviral vectors-mediated mouse genetic engineering regulatory T cells （Treg） infused after allogeneic bone marrow transplantation （allo- BMT） on graft-versus-host disease （GVHD） in mice. Methods Lentivirus-mediated expression of Forkhead box P3 （Foxp3） converted CD4＋ CD25＋ T cells from Balb/c mice into engineered Tregs in vitro. An allo-BMT model of Balb/c→C57BL/6 mice was established. Mice were randomly assigned into four groups： （1） The recipients in engineering Treg group were injected with 5×10^6 donor bone marrow cells and 5×10^6 splenocytes plus 5×10^6 genetic engineering Treg; （2） The recipients in transplantation control group were injected with 5×10^6donor bone marrow cells and 5×10^6 splenocytes; （3） The recipients in radiation group were injected with 0. 2 ml RPMI 1640; （4） The recipients in empty vector control group were injected with 5×10^6 donor bone marrow cells and 5×10^6 splenocytes plus 5×10^6 empty vector transduced CD4＋ CD25- T cells. Survival time, clinical GVHD score or histopathological analysis （skin, liver and small intestine） were observed after alto-BMT. Chimerism of bone marrow cells from recipients survived for 60 days after transplantation was measured. Results The mean survival times in radiation group, transplantation control group, engineering Treg group and empty vector control group were （8. 8 ± 0. 6）, （36. 7 ± 2. 5）, （51.6 ±4. 0） and （34. 1 ± 2. 3）days respectively. The survival time in engineering Treg group was significantly prolonged as compared with other groups as judged by the logrank test （P〈0. 05）. Histopathological analysis in several target organs （skin, liver and small intestine） confirmed the presence of severe GVHD in transplantation control group and empty vector control group. No histological signs of GVHD were observed in recipients in engineering Treg group and clinical GVHD scores in this group were significantly decreased compared