XENOGENEIC NATURAL ANTIBODY TARGETS--STRUCTURE-FUNCTION

移植领域的一个主要挑战是 捐献器官短缺。 虽然异种移植可以解决这个问题， 问题，其潜在的使用受到超急性排斥反应的限制。 当器官被移植到两个人之间时不可避免地会发生的反应。 远缘物种。 超急性异种移植排斥反应是 以血管损伤的明显证据为特征， 由天然抗体和补体的反应引发， 受体与供体的血管内皮衬里 器官. 拟议研究的总体目标是阐明 超急性异种移植排斥反应的发病机制和发展 预防战略;实现这些目标将有助于 涉及异种移植用于改善疾病的应用， 人类 拟议研究的一个具体目标是进一步表征 猪内皮细胞糖蛋白gp 135，似乎是 人类天然抗体的最重要靶点 排斥反应。针对此的单克隆抗体 糖蛋白和/或部分氨基酸序列将用于分离 并克隆全长cDNA。 将使用蛋白质和cDNA序列 基于与其他已知的gp 135蛋白的同源性，推断gp 135蛋白的功能。 序列，因为它涉及到超急性 排斥反应其他猪内皮细胞 发现糖蛋白在病理生理学上是重要的，这些 糖蛋白也将被研究。 该项目的另一个目的是确定人类自然的作用， 抗体和补体介导异种内皮损伤。 人天然抗体和人及鼠单克隆抗体 针对特异性猪内皮细胞抗原，包括 gp 135，将在有和没有补体的情况下进行测试，以确定 刺激或“激活”猪内皮细胞。的表现 内皮细胞激活，因为它发生将与特定的 抗内皮细胞抗体识别的结构和活性 补体部分或其组合作为刺激物。

One major challenge in the field of transplantation is the critical shortage of donor organs. While xenotransplantation might address this problem, its potential use is limited by the hyperacute rejection reaction that inevitably occurs when organs are transplanted between phylogenetically distant species. Hyperacute xenograft rejection is characterized by prominent evidence of vascular injury that is thought to be initiated by the reaction of natural antibodies and complement of the recipient with the endothelial lining of blood vessels of the donor organ. It is the overall objective of the proposed research to elucidate the pathogenesis of hyperacute xenograft rejection and to develop strategies to prevent it; the achievement of these goals will contribute to the application of xenotransplantation for amelioration of disease in humans. One specific aim of the proposed research is the further characterization of a porcine endothelial cell glycoprotein, gp135, which appears to be the most important target of human natural antibodies in the initiation of the rejection reaction. Monoclonal antibodies directed against this glycoprotein and/or partial amino acid sequences will be used to isolate and clone full length cDNA. The protein and cDNA sequences will be used to deduce the function of gp135 based on homology with other known sequences and as it relates to the pathophysiology of hyperacute rejection. To the extent that other porcine endothelial cell glycoproteins are found to be pathophysiologically important, these glycoproteins will be investigated as well. Another aim of this project is to define the roles of human natural antibodies and complement in mediating injury to xenogeneic endothelium. Human natural antibodies and human and murine monoclonal antibodies directed against specific porcine endothelial cell antigens, including gp135, will be tested with and without complement for the ability to stimulate or "activate" porcine endothelial cells. The manifestations of endothelial cell activation as it occurs will be related to the specific structures recognized by anti-endothelial cell antibodies and the active complement moieties or combination thereof required as a stimulus.