中文摘要：

目的 通过慢病毒载体介导的鼠叉状头螺旋转录因子（Foxp3）基因表达构建鼠基因工程调节性T细胞（Tr）,探讨输注基因工程Tr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Foxp3基因转导入BALB/c小鼠的CD4＋CD25-T淋巴细胞,即为基因工程Tr细胞.建立小鼠异基因骨髓移植模型,在移植时联合输注基因工程Tr,通过受鼠移植后生存期、组织病理学改变、炎性细胞因子浓度等指标评价其防治GVHD的作用.并与单纯照射组、移植对照组、空载体对照组相比较.结果 单纯照射组、移植对照组、工程Tr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Tr组小鼠存活时间明显长于其他各组（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Tr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.移植后移植对照组、工程Tr组、空载体对照组受鼠血清IFN-γ、IL-2和TNF-α浓度在21～28 d时达高峰,工程Tr组在21 d时IFN-γ、IL-2和TNF-α浓度高峰较其他两组为低（P＜0.05）.结论 小鼠异基因骨髓移植时联合输注基因工程Tr细胞可通过减少受鼠移植后炎性细胞因子的分泌有效减少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（Tr） infused after allogeneic bone marrow transplantation（allo-BMT） on graft-versushost disease（GVHD） in mice. Methods Lentivirus-mediated expression of forkhead box P3 （Foxp3） converted CD4 ＋ CD25 - T cells from BALB/c mice into engineered Tr in vitro. An allo-BMT model of BALB/c→C57BL/6 mice was established. After irradiation, the recipients were injected with donor cells along with genetic engineering Tr. Survival time, histopathological analysis, serum levels of inflammatory cytokines were observed after allo-BMT. Results The mean survival times in radiation group, transplantation control group, engineering Tr group and empty vector control group were （ 8.8 ± 0.6 ） d, （ 36.7 ± 2.5 ） d, （ 51.6 ± 4.0 ） d and （ 34.1 ± 2. 3 ） d. The survival time in engineering Tr group was significantly increased as compared to other groups as judged by the log-rank 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 Tr group. The serum levels of IFN-γ, IL-2 and TNF-α were all increased after transplantation in above groups. The peaks of concentrations of IFN-γ, IL-2 and TNF-α in engineering Tr group were significantly decreased compared to transplantation control group and empty vector control group at day 21 （ P 〈 0. 05 ）. Conclusion Co-injection of genetic engineering Tr can efficiently prevent recipients from lethal GVHD during allo-BMT in mice by reducing the serum levels of inflammatory cytokines.