大鼠供心转染CTLA4-Ig基因抑制心脏移植后排斥反应

Prolonged cardiac allograft survival by means of intracornary infusion with CTLA 4-Ig gene

目的研究大鼠供心转染CTLA4-Ig基因抑制心脏移植术后排斥反应的可行性。方法以BN大鼠为供者,Lewis大鼠为受者,建立心脏移植模型。将实验分为2组。对照组:供心获取过程中不给予任何干预处理;实验组:在供心获取的过程中,以质粒载体携带CTLA4-Ig(pUF1-CTLA4-Ig)经过冠状动脉灌注供心。采用逆转录聚合酶链反应(RT-PCR)检测供心组织中CTLA4-IgmRNA的表达,观察移植心存活时间;酶联免疫法(ELISA)检测血清γ-干扰素(IFN-γ)和白细胞介素-4(IL-4)水平;观察移植心的组织学改变;用免疫组织化学SABC法检测移植心组织中CD4+和CD8+T细胞的浸润。结果实验组移植心存活时间较对照组明显延长[(11.70±1.24)dvs(5.62±0.74)d,P<0.05]。移植后5d,实验组移植心组织中可见CTLA4-IgmRNA的表达;对照组病理学检查可见心肌间质出现弥漫性的炎性细胞浸润,伴有局部的心肌坏死,组织间质水肿,实验组仅有局灶性血管外周及心肌间质内炎性细胞浸润,未见坏死;对照组移植心组织中浸润的CD4+和CD8+T细胞数量明显高于实验组(P<0.01);实验组血清IFN-γ水平明显低于对照组(P<0.01),但血清IL-4水平差异无统计学意义(P>0.05)。结论经冠状动脉灌注转染CTLA4-Ig基因,可以抑制心脏移植后排斥反应。

Objective To investigate the feasibility of prolonged cardiac allograft survival by means of intracornary infusion with CTLA4-Ig gene. Methods Hearts from BN rats were transplanted into the abdomen of Lewis recipients. The expriments were divided 2 groups： （1） control group：with on spcific treatment; （2） experimental group： Donor hearts were infused with pUF1-CTLA4-Ig by means of coronary artery before transplantation. The expression of CTLA4-Ig in the transplanted hearts was detected by R.T PCR, the levels of serum interferon-γ and interleukin-4 in recipients after heart transplantation determined by ELISA analysis, and the infiltrating CI34 and CI）8 T cells in transplanted hearts were detected by immunohistochemistry assay. Results The survival time of the allografts in the gene-transfected group was significantly prolonged as compared with that in the control group [（ 11.70 ± 1.24） days vs （5.62 ± 0. 74） days, P〈 0. 05]. The levels of serum interferon-γ in transfected group was much lower than in the control group （P〈0. 05）. The expression of CTLA4-Ig mRNA was detected at 5th day after transplantation by RT-PCR. Conclusion Infusion with CTLA4-Ig gene by means of coronary artery can prolong the survival of the cardiac allograft.