预注射供体凋亡细胞对移植胰岛存活及外周血T淋巴细胞功能的影响

摘要

目的：研究预先注射供体来源的凋亡细胞对移植胰岛存活时间及外周血T淋巴细胞功能的影响。方法分别利用直线加速器照射及热休克（56℃水浴箱震荡摇1 h）的方法获取供体凋亡细胞和坏死细胞。利用链脲佐菌素（STZ）腹腔注射的方法将接受胰岛移植的大鼠42只诱导为糖尿病模型大鼠后，随机分为4组，分别在胰岛移植前1周注射生理盐水（9只）、正常细胞（12只）、凋亡细胞（12只）及坏死细胞（9只）；在注射处理后第7天进行肾包囊下胰岛移植。通过血糖变化评估胰岛存活时间，并在胰岛移植前（注射后1周）、胰岛移植后1周、2周以及发生排斥反应后取3只大鼠采取外周血，利用四甲基偶氮唑盐（MTT）法检测外周血T淋巴细胞的增殖功能；利用多功能流式点阵仪检测外周血T淋巴细胞亚群细胞因子干扰素（IFN）-γ、白介素（IL）-10的水平及酶联免疫方法测定转化生长因子（TGF）-β1水平。结果凋亡细胞预处理能明显延长胰岛移植物存活时间，并抑制外周血T淋巴细胞对刀豆蛋白A刺激的增殖能力；同时在移植后1周、2周抑制了外周血IFN-γ的分泌，而增加了IL-10、TGF-β1的分泌（均P<0.05）。结论凋亡细胞可能通过抑制外周血T淋巴细胞的增殖活化能力，改变不同T细胞亚群细胞因子的分泌调节受体的免疫反应，从而抑制排斥反应，延长移植物存活。%Objective To study the influence of pre-injection of donor apoptotic cells in the survival of islet grafts and the function of T lymphocytes in the peripheral blood. Methods The donor apoptotic cells and necrotic cells were ob-tained respectively by X-irradiation from electron linear accelerator and a heat-shock procedure (water bath box 56℃, 1 h). The diabetic rats for islet transplantation (n=42) were induced by a single intraperitoneal injection of streptozotocin (STZ), then were randomly divided into four groups:rats were injected by physiological saline group (n=9), normal cells group (n=12), apoptotic donor cell group (n=12) and necrotic donor cell group (n=9). On the seventh day, each group received islet transplantation under the renal capsule. The blood glucose level was detected to reflect the survival of the islets. The periph-eral blood samples of three rats in each group were obtained at different observation times. The proliferative activity of T lym-phocytes was determined by MTT method. The levels of cytokines interferon (IFN)-γ, interleukin (IL)-10 in peripheral blood were measured by Luminex 100 Integrated System, and transforming growth factor (TGF)-β1 by ELISA respectively at 0 d, 1 week, 2 weeks and after rejection. Results The survival time of islets was significantly prolonged by the pre-intervention of apoptotic cells, and the proliferative activity of T lymphocytes stimulated by ConA was inhibited. Meanwhile, the extent of the increased level of IFN-γwas inhibited significantly at 1 week and 2 weeks after transplantation (P<0.05), the levels of IL-10 and TGF-β1 were significantly increased before transplantation, 1 week and 2 weeks after transplantation (P<0.05). Conclusion Our results demonstrated that the pre-treatment of donor apoptotic cells can regulate the recipient’s immune reactive state by inhibiting the proliferative activity of T lymphocytes and changing the levels of cytokines from different sub-sets of T lymphocytes, and finally resulted in the prolonging of the survival of islet grafts.