肿瘤坏死因子相关凋亡诱导配体转基因治疗鼠角膜移植免疫排斥的研究

The effect of TNF-related apoptosis-inducing ligand on in vivo graft survival after ex vivo adenovirus-mediated gene transfer to cornea

目的 探讨肿瘤坏死因子相关凋亡诱导配体 (tumornecrosisfactor relatedapoptosis inducingligand ,TRAIL)对角膜移植免疫排斥反应的作用。方法 选择受体BALB/c和供体C5 7BL/ 6小鼠 ,各 32只。将其分为正常对照组、可溶性死亡受体 5 (solubledeathreceptor 5 ,sDR5 )浸泡组、TRAIL的重组腺病毒 (Ad TRAIL)转染组及绿荧光蛋白 (greenfluorescentprotein ,GFP)的重组腺病毒 (Ad GFP)转染组 ,每组 8只。采用免疫组化技术分别对病毒接种后不同时间的体外角膜内皮细胞中TRAIL蛋白进行检测。将携带有Ad TRAIL的供体C5 7BL/ 6小鼠角膜移植片移植到受体BALB/c小鼠眼上 ,观察术后角膜免疫排斥反应发生的时间及炎性反应强度 ,并检测免疫排斥的角膜移植片中CD4+及CD8+T淋巴细胞的浸润情况。采用DNA原位缺口末端标记检测角膜移植片中的凋亡细胞。结果 Ad TRAIL转染 3d ,5 0 %以上内皮细胞TRAIL蛋白表达阳性 ;转染 10～ 14d时 ,内皮细胞TRAIL蛋白表达程度最高 ;转染 3周后 ,TRAIL蛋白表达阴性。正常对照组、sDR5浸泡组、Ad TRAIL转染组及Ad GFP转染组小鼠角膜移植术后发生免疫排斥反应的平均时间分别为 17 7、12 3、2 2 0及 17 4d ;4个组间角膜免疫排斥反应时间比较 ,差异有显著意义 (P =0 0 0 0 )。

Objective To observe the effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on the allograft rejection after ex vivo adenovirus-mediated gene transfer to cornea. Methods By co-culture with corneal graft, a replication-deficient adenovirus encoding the mTRAIL gene (Ad-TRAIL) was transduced into graft endothelium of mice. Immunohistochemistry was used to look for the TRAIL protein expression in ex vivo corneal endothelium. The grafts obtained from C57BL/6 mice that carried Ad-TRAIL were transplanted into the eyes of BALB/c mice. The occurrence time, the intensity of immunorejection and the immersion of CD4+ and CD8+ T lymphocytes were observed. TUNEL was used to detect the cell′s apoptosis in the corneal grafts. We used uninfected group, Ad-green-fluorescent protein (GFP) transduced group and soluble death receptor 5 (sDR5) group as controls. Results TRAIL protein expression was seen on more than 50% of endothelium 3 days after Ad-TRAIL transduced into corneal grafts in vitro,with higher expression for 2 weeks,then gradually reduced to negative till 3 weeks. The mean time of allograft rejection was 17.7 days in uninfected group, 22 days in Ad-TRAIL group, 17.4 days in Ad-GFP group and 12.3 days in sDR5 group. The differences among four groups were statistically significant. There were distributions of CD4+,CD8+ T lymphocytes and apoptotic cells in all rejected corneal grafts. Conclusions TRAIL protein can inhibit corneal allograft rejection in mice and prolong the survival time of transplanted allografts.