调节性树突状细胞诱导大鼠供者特异性移植物免疫低反应

Regulatory dendritic cells treatment induce donor-specific allograft hyporesponsiveness

目的探讨调节性树突状细胞（rDC）对大鼠同种异体排斥反应的调控及其效应。方法大鼠腹腔心脏移植前7d，受者静脉输注供者来源未成熟DC（imDC）、成熟DC（matDC）、rDC和磷酸盐缓冲液（PBS）。观察移植物体存活时间，比较排异反应病理分级，逆转录聚合酶链反应（RT—PCR）检测受者淋巴结细胞叉状头／翅膀状螺旋转录因子（Foxp3）mRNA表达。结果rDC组（18．6d）移植物平均生存时间较imDC（12．1d）、matDC（6．8d）和PBS（7．1d）组显著延长（P〈0．05）。检测受者淋巴结组织中Foxp3mRNA的表达结果显示：PBS组几乎不表达，matDC组表达较低，imDC组和rDC组表达明显上调，与前两组比较差异有统计学意义（P〈0．01），但两者间差异无统计学意义（P〉0．05）。结论rDC能延长同种异体大鼠心脏移植物的存活时间，诱导受者对供者移植物的特异性免疫低反应。

Objective To investigate the effect and mechanism of regulatory dendritic cell （rDC） in allograft rejection. Methods Graft recipients were infused （i. v. ） with 1×10^6 rDC, imature dendritic cell （imDC） , MatDC or PBS respectively 7 days preceding heterotopie fully MHC-mismatched heart trans- plantation. Graft survival was monitored by transabdominal palpation of the donor heart. The forkhead box P3（Foxp3） mRNA expression was determined in lymph node eells at day 7 after the i. v. infusion by re- verse transcriptase-polymerase chain reaction （RT-PCR）. The sample of allogr＇aft had been studied by he- matoxylin and eosin （HE） stain and scored according to the International society of Heart. Results rDC prolonged the mean survival time （MST） of allograft, which was 18.6 days, as compared to PBS group （7. l days; P〈0.01）, imDC group （12.1 days; P〈0.05） and matDC group （6.8 days; P〈0.01）, respectively. Infusion of rDC and imDC resulted in increased foxp3 mRNA expression as compared to infusion of matDC and PBS, respectively. Conclusion Pretreatment with donor type rDC resulted in pro- longed survival of a completely MHC-mismatched heart allograft, rDC is more efficacious than the classical imDC in the regulation of the alloimmune response.