Lazzeri M, Mora M, Mulder L C, Marsicano G, Marinucci G, Boschi M, Bruzzone P, Alfani D, Cortesini R, Rossini M
Chiron-Biocine Research Center, Siena, Italy.
J Urol. 1998 Apr;159(4):1364-9.
The major obstacle to successful discordant kidney xenotransplantation is hyperacute rejection (HAR). Complement plays a key role in the induction of HRA, defined by endothelial cell activation, loss of vascular integrity, hemorrhage and thrombosis. The activation of complement is tightly controlled by a number of species-specific regulatory proteins which inhibit, at different points, the cascade of events leading to the formation of the membrane attack complex (MAC). We have tested the hypothesis that kidneys derived from transgenic mice expressing two human complement inhibitors, Decay Accelerating Factor (hDAF) and Membrane Cofactor Protein (MCP), could be protected from human complement-mediated damage.
Control and transgenic mice were perfused with human plasma by cannulation of the right jugular vein, at a perfusion rate of 10 microL./min. for two hours. Complement C3 deposition was detected on kidney sections by immunohistochemistry using specific FITC antibody. Complement-induced tissue damage was evaluated by histopathological examination.
Heavy deposition of complement C3 was observed on kidneys derived from perfused control mice. This was associated with a characteristic HAR pathology of severe interstitial hemorrhage, inflammatory reaction, loss of glomerula and tubuli structure. Kidneys derived from mice transgenic for hDAF or hMCP were partially protected from both complement C3 deposition and tissue damage. The expression of both hDAF and hMCP in double transgenic mice significantly increases the protection from human complement-mediated damage.
A novel model of in vivo perfusion with human plasma has been adopted to recreate the initial event of HAR. Our data show that this murine model could be very valuable to determine the effect of transgenic human molecules in protecting vascularized organs from human complement attack.
成功进行不匹配肾异种移植的主要障碍是超急性排斥反应（HAR）。补体在HAR的诱导过程中起关键作用，其表现为内皮细胞活化、血管完整性丧失、出血和血栓形成。补体的激活受到多种物种特异性调节蛋白的严格控制，这些蛋白在不同阶段抑制导致膜攻击复合物（MAC）形成的一系列事件。我们检验了这样一个假设，即源自表达两种人类补体抑制剂衰变加速因子（hDAF）和膜辅因子蛋白（MCP）的转基因小鼠的肾脏可以免受人类补体介导的损伤。
通过右颈静脉插管，以10微升/分钟的灌注速率对对照小鼠和转基因小鼠灌注人血浆，持续两小时。使用特异性异硫氰酸荧光素（FITC）抗体通过免疫组织化学检测肾切片上补体C3的沉积。通过组织病理学检查评估补体诱导的组织损伤。
在灌注的对照小鼠的肾脏上观察到补体C3的大量沉积。这与严重的间质出血、炎症反应、肾小球和肾小管结构丧失等典型的HAR病理相关。源自hDAF或hMCP转基因小鼠的肾脏在补体C3沉积和组织损伤方面均受到部分保护。双转基因小鼠中hDAF和hMCP的表达显著增强了对人类补体介导损伤的保护作用。
采用了一种用人血浆进行体内灌注的新型模型来重现HAR的初始事件。我们的数据表明，这种小鼠模型对于确定转基因人类分子在保护血管化器官免受人类补体攻击方面的作用可能非常有价值。
