Blastocyst MHC基因转染延长小鼠移植心脏存活时间

The effect of blastocyst MHC gene transfection on the survival of mouse heart grafts

目的 探讨Blastocyst MHC基因经供心冠状动脉转染对移植心脏存活时间的影响。方法分别以近交系健康雄性Balb／c小鼠和C57BL／6小鼠为供、受者，制备小鼠颈部心脏移植模型，对照组供心以0～4℃托马斯Ⅱ溶液灌注；环孢素A（CsA）组供心用前述方法灌注，术后受者腹腔注射CsA5mg·g^-2·d^-1；转染组供心以含BlastocystMHC基因转染质粒的托马斯Ⅱ溶液灌注；联合处理组供心以含BlastocystMHC基因转染质粒的托马斯Ⅱ溶液灌注，术后腹腔内注射CsA。观察各组移植心脏存活时间和组织学变化，测定移植心脏组织中BlastocystMHC基因mRNA表达以及外周血CD4＋CD25＋调节性T淋巴细胞（Treg细胞）及CD3＋CD8＋T淋巴细胞的变化。结果CsA组、转染组和联合处理组移植心脏存活时间较对照组明显延长（P〈0．05），其中以联合处理组最为显著，达（20．50±5．61）d。转染组术后1、3d的BlastocystMHC基因mRNA表达水平较对照组明显升高（P〈0．05）。术后7d，联合处理组的排斥反应程度最轻，其冠状动脉内膜增生也最轻。术后7d，CsA组和联合处理组Treg细胞明显多于对照组（P〈0．05），而CD3＋CD8＋T淋巴细胞明显少于对照组（P〈0．05）。结论移植前转染BlastocystMHC基因能够通过上调Treg细胞、抑制CD3＋CD8＋T淋巴细胞而延长小鼠移植心脏存活时间，与CsA联合有协同作用。

Objective To investigate the effects of Blastocyst MHC gene transfection to coronary on the survival time of mouse heart grafts and the mechanism Methods Inbred male Balb/c mice and C57BL/6 mice were selected as donors and recipients respectively, to construct mouse cervical heart transplantation models. In the control group; the donor hearts were perfused using the 0-4℃ St. Thomas Ⅱ solution in the cyclosporirine A （CsA） group, the donor hearts were perfused as same as the control＇s and received intraperitoneal injection of CsA （5 mg.g^-1-d^-1 ） after surgery; in the transfection group the donor hearts were perfused using St. Thomas Ⅱ solution with Blastoeyst MHC gene plasmid in the combined treatment group, the donor hearts were perfused using St. Thomas Ⅱ solution with Blastocyst MHC gene plasmid and received intraperitoneal injection of CsA （5 mg.g^-1.d^-1 ） after surgery. The survival time of transplanted heart allografts were observed, and their histopathological changes and the degrees of coronary intimal hyperplasia were estimated. Blastocyst MHC gene mRNA expression levels were detected by real time fluorescence quantitative RT-PCR. Flow cytometry was applied in assessment of the levels of CD4＋ CD25 ＋ regulatory T cells （Treg） and CD3＋ CD8＋ T cells. Results The survival time in the CsA group, transfection group and combined treatment group was significantly longer than in the control group （P〈0. 05） and that in the combined treatment group was the longest, up to （20, 50 ± 5, 61） days. On the postoperative day 1 and 3, Blastoeyst MHC gene mRNA expression level in the transfeetion group was significantly higher than that in the control group （P〈0.05）, On the postoperative day 7, the degrees of rejection and coronary intimal hyperplasia in the combined treatment group were the lightest. On the postoperative day 7 the number of Tregs in the CsA group and the combined treatment group was significantly increased as compared with that in the control group （P〈0. 05）, hut that of CD3＋ CD8＋ T cells in the CsA group and the combined treatment group was less than that in the control group （P〈0.05）. Conclusion Blastocyst MHC gene transfection in mouse transplanted cardiac allograft can extend its survival time through upregulation of Treg and downregulation of CD3 ＋ CD8＋ T cells in the mice. The combination of Blastoeyst MHC gene and CsA may exert the synergic effects.