供者特异性T细胞疫苗延长同种肝移植存活及其机制的初步分析

A preliminary analysis on the mechanism of prolongation in the survival time of liver allografts induced by donor-specific T cell vaccination

为检测细胞因子(CK)在肝移植物中的表达,探讨供者特异性T细胞疫苗(TCV)延长同种肝移植存活的机制。术前分别用特异和非特异TCV免疫受者,另设单纯移植对照。大鼠原位肝移植后观察肝移植物的存活时间(MST);术后第7天获取移植物,作组织切片观察;通过RT-PCR检测肝移植物内IL-2、IFN-γ、IL-4和IL-10的表达水平;进行混合淋巴细胞反应。结果发现供者特异性LCTCV组MST(15.7±4.2)d比非特异性LTCV组(11.3±2.7)d显著延长(P<0.01),而单纯移植组MST为(5.7±1.4)d(P<0.05);组织切片观察特异性LCTCV组未发现明显排斥改变;与其他两组比较,特异性LCTCV组MLR受到显著抑制(P<0.01);RT-PCR显示:特异性LCTCV组IL-4、IL-10的表达水平显著高于其他两组,IL-2和IFN-γ在单纯移植组呈高表达,同时IFN-γ在非特异LTCV组有表达。实验表明:细胞因子网络调控在免疫耐受形成中发挥重要作用,IFN-γ和IL-2主要参与急性排斥反应,IL-4和IL-10促进同种耐受的形成,不同的微环境下同一种细胞因子所发挥的主要作用会有所变化。

To investigate the mechanism of prolongation in the survival time of liver allografts induced by donor-specific T cell vaccination （TCV）, rat recipients were immunized with donor-specific and non-specific TCV with orthotopic liver transplantation（OLT） served as control, laver grafts were harvested at 7th day after OLT and the median survival time（MST） was recorded. Histological examination of the rejection reactions was conducted by hematoxylin and eosin staining and the one-way mixed lymphocyte reaction（MI.R） was performed as well. The expressions of cytokines（IL-2, IFN-γ, IL-4 and IL-10） in liver grafts were assayed by RT-PCR. From this experiment, it was demomstrated that the MST of liver grafts in group of rats receiving the donorspecific TCV（ 15.7±4.2）days was significantly prolonged in comparison with that of the non-specific TCV （11.3±2.7）days and the MST of liver grafts from OLT control was （5.7±1.4） days. Histological examination showed that liver damage was noticeable in group of OI.T control, and slight damage could be demonstrated in non specific TCV group; however, there was no overall architechural change in donor-specific TCV group. Compared with other two groups, the MI.R in the donor specific TCV group was significantly suppressed. As demonstrated by RT PCR, the expressions of II_4 and II-10 were significantly higher than lhose of the other two groups, while IL-2 and IFN y appeared to be hightly expressed in the OLT control group, and IFN 7 was moderately expressed in the non specific TCV group. It is concluded that cytokines network modulation plays an important role in the development of immuno-tolerance and it depends on the concrete micro environ ment.