ESTABLISHMENT OF NEW IMMUNOSUPPRESSIVE STRATEGY USING GENE TRANSFECTION TECHNIQUE

据报道，异种抗体诱导的内皮细胞活化和凋亡可能是异种移植排斥反应的主要原因，也可能是异种抗体直接破坏细胞的原因。因此，预防内皮细胞凋亡可以预防移植物冠状动脉粥样硬化（GCAS）。本研究在仓鼠心脏移植（HTx）模型中，采用FK506和眼镜蛇毒因子（CVF）阻断补体和细胞型排斥反应，研究转染细胞保护基因Bcl-2对移植物存活和GCAS的影响。【材料与方法】采用Ono-Lindsey法将14只金仓鼠心脏移植至Lewis大鼠腹腔。所有大鼠均肌肉注射CVF （0.2 mg/Kg，第0天和第1天）和FK506 （1 mg/Kg，第0天和第1天）。这些心脏被分成两组。b（+）组和- b（-）组分别用含Bcl-2基因载体的hvj脂质体和仅用载体灌注冠状动脉转染移植物。排斥反应的定义是外部触诊停止。采用H-E染色和Bcl-2免疫组化染色对移植物进行评价。【结果】两组间移植物存活率无显著差异。HTx后3周内，Bcl-2仅在b组（+）移植物中表达。虽然b组（-）的GCAS评分显著高于b组（+），但HTx治疗后4周以上各组间差异无统计学意义。【结论】虽然两组间移植物存活率无显著差异，但这些数据提示，基因转染Bcl-2可能阻止内皮细胞活化，从而预防移植物冠状动脉粥样硬化。

It has been reported that endothelial cell activation and apoptosis induced by xenoantibody may play a major role in concordant xenograft rejection as well as direct cell destruction by xenoantibody. Thus, prevention of endothelial cellular apoptosis may prevent graft coronary atheroscrelosis (GCAS). In the present study, the effects of gene transfection of cytoprotective gene, Bcl-2 in graft survival and GCAS was investigated in a hamster-to-rat cardiac transplant (HTx) model in which the recipients were treated with FK506 and cobra venom factor (CVF) to block complement and cellular type rejection.【Material and Method】 14 Golden Hamster hearts were transplanted into Lewis rat abdomen using Ono-Lindsey methods. All rats were given CVF (0.2 mg/Kg ; day 0 and 1) and FK506 (1 mg/Kg from day 0) intramuscularly. These hearts were divided into two groups. In Group-B (+) and -B (-), grafts were transfected by perfusing coronary artery with HVJ-liposome containing vector with Bcl-2 gene and only vector, respectively. Rejection was defined by cessation of palpation from outside. The explanted grafts were evaluated by H-E staining and immunohistochemical staining of Bcl-2.【Results】 Graft survival was not significantly different in these groups. Bcl-2 was expressed only in the graft of Group-B (+) within 3 weeks after HTx. Although GCAS score in Group-B (-) was significantly higher than that in Group-B (+), there was no difference between those more than 4 weeks after HTx.【Conclusion】 Although there was no significant difference in graft survival between both groups, these data suggested that gene transfection of Bcl-2 may prevent endothelial cell activation resulting in preventing graft coronary astheroscrelosis in concordant xenografts.