腺病毒介导的CD40Ig基因治疗诱导异基因大鼠心脏移植物的长期存活

目的:通过腺病毒介导的CD40Ig基因治疗,阻断受体体内CD40/CD154共刺激途径,诱导异基因大鼠之间的心脏移植耐受,并探讨相关机制。在将异基因DA大鼠的心脏移植给受体LEW大鼠后,即经门静脉输注携带CD40Ig基因的腺病毒(AdCD40Ig,5×109 pfu)。观察、记录心脏移植物的存活时间。ELISA检测受体大鼠体内CD40Ig蛋白的表达。通过MLR,IL-2逆转实验及Th1/Th2型细胞因子表达的检测,研究耐受的机制。结果:与未处理对照组相比,携带绿色荧光蛋白基因的腺病毒(AdEGFP)给予组,移植物的存活时间未见明显延长;AdCD40Ig腺病毒给予组,异基因大鼠心脏移植物平均存活时间延长至(142.8±26.8)天。ELISA检测表明,CD40Ig蛋白在受体体内表达时间较长,但随时间的推移表达水平逐渐下降。Th1和Th2型细胞因子的检测结果显示,耐受大鼠体内未发现这两类细胞因子偏移的现象。MLR证明耐受大鼠对供体抗原表现为特异性低应答。IL-2逆转实验表明,该耐受形成的早期与克隆无能有关。结论:经.AdCD40Ig腺病毒基因治疗的受体大鼠可以产生特异性的移植耐受,使异基因大鼠心脏移植物长期存活。

Adenovirus-mediated gene transfer of CD40Ig gene induced long-term survival of cardiac allograft in rats

Objective:To induce long-term survival of cardiac allograft in rats by adenovirus-mediated gene transfer of CEMQIg gene, and to investigate the potential mechanisms involved in the induction of transplantation tolerance. Methods: The donor cardiac allograft from DA rats was heterotopically transplanted into the abdomen of LEW recipient rats, and recombinant adenoviruses containing EGFP gene or CD40Ig gene at a dose of 5 x ICf pfu were administered via portal vein, respectively, during the operation. The graft survival was monitored by daily palpation. The expression of CD4QIg fusion protein in the recipients was detected via EIISA. The tolerant mechanism was investigated via MLR, IL-2 reverse experiment and analyzing the expression of Thl/Th2 type cytokines in the recipients.Results: Compared with the untreated recipients, the mean survival time(MST) of the cardiac allograft was not prolonged in the recipients treated with AdEGFP adenovirus, whereas MST were prolonged significantly to 142.8 ?26.8 d in the recipients administered with AdCD40Ig adenovirus. The expression of CD40Ig fusion protein remained a long time but the levels gradually decreased. The results of MLR indicated that the induced tolerance in the recipients was donor-specific. The results of IL-2 reverse experiment demonstrated that the tolerance mechanisms were involved clonal anergy at the early stage of the established tolerance. The expression pattern of Thl/Th2 type cytokines did not indicate the polarization of Thl/Th2 type cytokines in the experimental models. Conclusion: A single injection of the defined dose of adenovirus containing CD40Ig gene via portal vein during operation is enough to induce long-term survival of cardiac allograft in rats.