Regulation of rejection against zenotransplantation by gene transfer of guinea pig species-specific complement regulatory molecules

为了保护自身细胞膜上的补体激活，补体的膜抑制剂限制同种血清的补体激活(Okada等人)。1983年)。在异种移植中，调节供体器官补体的激活对克服超急性排斥反应非常重要。现已培育出表达人补体调节膜抑制因子的转基因猪，其中包括衰变加速因子(DAF)、膜辅助因子蛋白(MCP)和HRF2O(2OkDa同源限制因子)，并用作猪到灵长类动物器官移植的模型。最近，为了在实验动物中鉴定调控分子，我们克隆了豚鼠(Gp)DAF和gpMCP以及大鼠512抗原(Rat Crry)和大鼠DAF和大鼠MCP的cDNA。此外，我们还分析了大鼠DAF和大鼠MCP的基因定位，表明小鼠MCP基因与远端染色体上的Cr2基因紧密连锁。gpDAF是由单一拷贝基因选择性剪接产生的多个异构体组成的。这些异构体主要由糖基磷脂酰肌醇锚定形式和跨膜形式组成，这些形式在人DAF中不存在。我们将这六种主要异构体的cDNA导入实验动物，并对其功能差异进行了评估，以选择最佳的候选基因导入实验动物。

To protect complement activation on self cell membranes, membrane inhibitors of complement restrict complement activation of homologous serum (Okada et al. 1983). In xenotransplantation, regulation of complement activation on donor organ is very important to overcome hyperacute rejection. Transgenic pigs that express human complement regulatory membrane inhibitors which include decay accelerating factor (DAF), membrane cofactor protein (MCP) and HRF2O (2OkDa homologous restriction factor), have been generated, and being used as models of transplantation of organs from pig to primates. Recently, for the purpose of identifying regulatory molecules among the experimental animals, we have cloned the cDNAs of guinea pig(gp) DAF and gpMCP, and rat 512 antigen (rat Crry) and rat DAF and rat MCP.Furthermore we also analyzed the gene orientation of rat DAF and rat MCP which shows close linkage between the mouse Mcp and Cr2 genes on distal chromosome 1.gpDAF consists of multiple isoforms generated by alternative splicing from a single copy gene. The isoforms are mainly comprised of a glycosylphosphatidylinositol anchored form and a transmenbrane form that are not present in human DAF.We have transfected cDNA of the six major isoforms and the functional differences were evaluated to choose the best candidate to transgene into the experimental animals.