白介素-35修饰间充质干细胞抑制小鼠心脏移植排斥反应的研究

Research of inhibiting cardiac allograft rejection in mice by interleukin-35 gene modifiedmesenchyma stem cells

目的探讨白介素(IL)-35修饰间充质干细胞(MSC)抑制小鼠心脏移植排斥反应的作用及机制。方法体外构建稳定表达IL-35的MSC(IL-35-MSC)。建立小鼠腹腔异位心脏移植模型,根据干预方式不同分为同系对照组、生理盐水对照组、MSC处理组及IL-35-MSC实验组(每组各12只)。各组随机选取6只小鼠术后第5天处死,HE染色观察移植心脏病理变化,ELISA检测外周血IL-35浓度,流式细胞术(FCM)检测脾脏T淋巴细胞亚群比例。剩余6只用于记录移植物存活期。结果成功构建小鼠心脏移植模型,同系对照组移植物术后28 d均存活;相较于生理盐水对照组存活(6.50±0.55)d及MSC处理组存活(12.00±0.89)d,IL-35-MSC实验组移植物存活期(18.50±1.64)d明显延长(n=6,P<0.01)差异有统计学意义。相较于其他组,IL-35-MSC实验组移植术后第5 d脾脏Th17比例和Th1/Th2比值降低,CD4+Foxp3+Treg细胞比例增高,差异具有统计学意义(n=6,P<0.01)。结论 IL-35-MSC能够有效减轻小鼠心脏移植排斥反应,以IL-35-MSC为基础的细胞免疫疗法有望成为诱导移植术后免疫耐受的新途径。

Objective To explore the effect and mechanism of interleukin-35 gene modified mesenchyma stem cells(MSC)on ameliorating cardiac allograft rejection and prolonging graft survival of transplanted heart in mice.Methods In this study,IL-35-MSC secreting IL-35 continuously and steadily were successfully constructed in vitro.Abdominal heterotopic heart transplantation model was established successfully.And they were randomly divided into syngeneic control group;saline control group,MSC treatment group and IL-35-MSC experimental group(n=12 each).Six mice were randomly selected for sacrificing at Day 5 post-operation for detecting the related indicators in each group:Hematoxylin eosin staining was used for pathological examination.Enzyme-linked immunosorbent assay(ELISA)was employed for detecting the concentration of IL-35 in peripheral blood and the proportion of T lymphocyte subsets in spleen was analyzed by flow cytometry(FCM).Then the remaining mice were used for recording the graft survival.Results The model of abdominal heterotopic heart transplantation in mice was successfully constructed.As compared with saline control group(6.50±0.55 d)and MSC treatment group(12.00±0.89 days),IL-35-MSC significantly alleviated rejection after transplantation and effectively prolonged the survival time of graft(18.50±1.64 days)(n=6,P<0.01).As compared with other groups,percentage of Th17 cells and Th1/Th2 ratio in spleen decreased significantly while the proportion of CD4+Foxp3+Treg increased significantly in IL-35-MSC experimental group at Day 5 post-transplantation(n=6,P<0.01).Conclusions IL-35-MSC may alleviate cardiac allograft rejection and prolong graft survival.And cellular immunotherapy based upon IL-35-MSC may provide a new approach for inducing immune tolerance.