T细胞疫苗诱导异种胰岛移植免疫耐受的实验研究

The Effects of T Cell Vaccination on Xenogeneic Islet Cell Transplantation

目的体外制备供体特异性T细胞疫苗(T cell vaccine),探讨T细胞疫苗免疫(T cell vaccination)诱导异种胰岛细胞移植免疫耐受的作用。方法腹腔注射链脲佐菌素诱导建立Balb/c小鼠Ⅰ型糖尿病模型,用酶消化法和密度梯度离心法无菌分离纯化Wistar大鼠胰岛细胞。制备Balb/c小鼠针对Wistar大鼠的T细胞疫苗:实验随机分为三组,G1:糖尿病小鼠对照组;G2:胰岛细胞移植组,糖尿病小鼠+胰岛细胞移植+1640培养液(对照组);G3:胰岛细胞移植加T细胞疫苗免疫组,糖尿病小鼠+胰岛细胞+T细胞疫苗(实验组),于d1,d7,d14,d21实验组Balb/c小鼠接种TCV(1×107/mL),对照组用1640替代。接种前和每次接种后第5d分别进行混合淋巴细胞反应。胰岛细胞移植:将Wistar大鼠的胰岛按1200～1500IEQ/kg经肝门静脉导入小鼠体内,移植后观测血糖和体重变化。结果异种胰岛细胞移植可以诱导I型糖尿病小鼠血糖降至正常水平且维持一段时间,对照组小鼠移植后(5.12±1.36)d即发生排斥,实验组移植物存活时间达(20.25±3.45)d。结论TCV能够有效延长异种胰岛移植物的存活时间,是一种潜在诱导异种胰岛移植免疫耐受的方法。

Objective To explore the the effects of T cell vaccination on xenogeneic islet cell transplantation. Methods Balb/c mice （H2-d） were used as recipients and Wistar rats were used as donors. Type I diabetes mice model were made by injecting streptozotocin intravenously. Type Ⅰ diabetes mice were randomly divided into three groups,Group A：Diabetic mice with no transplantation and no TCV, Group B： Islet cell transplantation ＋RPMI1640 culture medium, Group C（experimental group）： Islet cell transplantation＋TCV.T cell vaccine was made by using attenuated spleen lymphocytes from Balb/c mice which were challenged with Wistar rat spleen lymphocytes in vitro and were stimulated with Con A. Balb/c mice as recipients were immunized with TCV on the time points of d1,d7,d14,d21 and;RPMI1640 culture medium was used in control group. One-way mixed lymphocyte reaction（MLR） was performed with effector of immunized Balb/c mice peripheric lymphocytes and stimulator of Wistar rat peripheric lymphocytes on the second day of T cell vaccination. Islet cells were isolated from Wistar rat pancreas using the protocol of enzyme digestion and density gradient centrif μ gation. Islet cells were transplanted into immunized Balb/c mice at the density of 1200 - 1500IEQ/kg by the way of portal vein injection. Recipient＇s blood glucose was monitored everyday and body weight was recorded weekly after transplantation. Results Xenogeneic islet cell transplantation can induce type I diabetic mice blood glucose to normal levels and remain for some time,the control group mice after transplantation （5.12 ± 1.36） days, which happened rejection,the experimental group graft survival time of up to（20.25 ± 3.45）days. Conclusion T cell vaccination can significantly prolong the survival time of xenogeneic pancreatic islet grafts;T cell vaccination is a potential approach to to induce xenogeneic islet transplant tolerance.