输注转染FasL基因的供者树突状细胞减轻小鼠心脏移植排斥反应

目的 探讨转染FasL基因的供者树突状细胞(DC)对小鼠心脏移植排斥反应的影响.方法 分离并培养C57BL/6小鼠骨髓DC,然后采用脂质体法以自行构建的pTracer-FasL真核表达质粒转染DC.以C57BL/6小鼠为供者,Balb/c小鼠为受者,将其分为转染组(n=12)、未转染组(n=12)及移植对照组(n=12).转染组小鼠心脏移植前7 d经阴茎背静脉注射1×106个转染FasL基因的供者DC;未转染组小鼠心脏移植前7 d经阴茎背静脉注射1×106个未转染的供者DC;移植对照组仅行心脏移植,不接受供者DC输注.供心均移植于受者腹腔内.各组中,6只小鼠用于观察移植心脏存活时间,另6只于术后7 d处死,取移植心脏,进行组织学观察及移植心脏排斥反应病理分级.结果 转染组、未转染组和移植对照组小鼠移植心脏存活时间的中位数分别为20 d、8.5 d和9 d,转染组移植心脏的存活时间明显长于未转染组和移植对照组(P＜0.01).转染组中,2只排斥反应的病理分级为0级,4只为1级;未转染组中,2只为2级,4只为3级;移植对照组中,1只为2级,5只为3级.转染组排斥反应的病理分级明显低于移植对照组(P＜0.01).结论 受者于心脏移植前输注转染FasL基因的供者DC,可有效延长移植心脏的存活时间,并减轻排斥反应的程度.

Alleviation of the heart transplantation rejection by infusion of FasL transfected DCs in mice

Objective To study the protective effect by infusion of the donor bone marrow derived dendritic cells (DCs) transfected with FasL in the grafts and its anti-rejection mechanism.Methods Mouse myeloid DCs were cultured in selective medium. FasL gene was transfected into DCs with Liposome. The heterotopic heart transplantation model in mice was established, then the experimental animals were divided into 3 subgroups as follows: subgroup 1-treated by DCs transfected with FasL (n = 12), subgroup 2-3 taken as controls: subgroup 2 (allograft transplantation, n = 12),subgroup 3 (normal DCs infusion, n= 12). On the 7th pre-operative day, DCs modified by FasL were transfused into recipients. The graft survivals were individually recorded and pathologically evaluated according to graft rejection grading on the post-operative day 7. Results Stable heterotopic heart transplantation model in mice was established successfully. In subgroup 1-treated by DCs transfected with FasL, the mean survival time (MST) of grafts was significantly longer than in subgroup 2 and subgroup 3 (20 days vs. 9 days, 8. 5 days, P＜0. 01), and pathological grading of rejection was significantly lower than in subgroups 2 and 3 (P＜0. 01). Conclusion Donor-derived DCs transfected with FasL gene could exhibit protective effect on grafts. The anti-rejection mechanism might be due to specially inducing apoptosis of T lymphocytes.