转人CRP基因在异种移植中的研究

目的：研究转入补体调节蛋白（CRP）DAF、MCP和CD59基因对抑制人补体激活从而克服超急性排斥反应的作用。方法：利用显微注射建立转人衰变加速因子（hDAF)小鼠和猪的模型和转梁hMCP及hCD59真核表达质粒的猪内皮细胞（EC），研究小鼠和猪EC表达抑制人补体激活的人补体调节蛋白（CRP）对异种移植超急性排斥反应的抑制作用。结果（1）转人DAF基因小鼠心脏用新鲜人血连续丛外灌注，转基因组心脏搏动时间（174．6min)比对照组（106．5min)明显延延长。（2）转hDAF基因猪心脏异位移植给猕猴、移植心最长存活90h，受者死亡前移植心仍有功能，移植心病理检查未见超急性排斥反应病理改变。（3）转DAF基因基因猪EC死亡率在不同浓度血清时均明显低于对照组，在转hDAF基因猪EC上再分别转染hMCP及hCD59真核表达质粒，转hDAF hMCP或hDAF hCD59在不同血清浓度时EC死亡率较单纯hDAF组明显下降（P＜0．05）。结论，转人DAF及MCP、CD59补体调节蛋白基因能克服人对异种器官或组织的超急性排斥反应。

A study of human DAF, CD59, MCP (CRPs) transgene in xenotransplantation

Objective In order to study the role of human complement regulatory protein (CRPs) transgene in including DAF, CD59 and MCP in overcoming hyperacute rejection (HAR). Methods and Results Hearts from DAF transgenic mice were continuously perfused in vitro by fresh human blood. Mean heart beating time was prolonged to 174.6 ?min in contrast to 106.5 ?min in the control group; In a porcine to primate heterotopic heart transplantation model, the longest survival time of recipients receiving heart from transgenic pig was more than 90?h, and the recipient died with functional graft. Pathologically, no evidence of HAR was observed. The death rate of human DAF transgenic pig endothelial cells (Ecs) in different dilution of human serum was significantly lower than in the normal Ecs. Plasmid encoding hCD59 or hMCP was transfected to hDAF transgenic pig Ecs, death rate of Ecs transfected with hDAF hMCP or hDAF hCD59 was lower than that in hDAF transgenic pig Ecs ( P < 0.05 ), indicating that hCD59 or hMCP transgene in addition to hDAF could inhibit complement activation more thoroughly, thus overcome HAR. Conclusion hDAF, CD59, MCP transgene could overcome HAR of human receiving xenografts. Two or more CRP genes expression in xenografts could enhance the inhibition of complement due to different mechanisms in the steps of complement activation .