Kroshus T J, Bolman R M, Dalmasso A P, Rollins S A, Guilmette E R, Williams B L, Squinto S P, Fodor W L
Department of Surgery, University of Minnesota, Minneapolis, USA.
Transplantation. 1996 May 27;61(10):1513-21. doi: 10.1097/00007890-199605270-00018.
The serious shortage of available donor organs for patients with end stage organ failure who are in need of solid organ transplantation has led to a heightened interest in xenotransplantation. The major barrier to successful discordant xenotransplantation is hyperacute rejection. Hyperacute rejection results from the deposition of preformed antibodies that activate complement on the luminal surface of the vascular endothelium, leading to vessel occlusion and graft failure within minutes to hours. Endogenous membrane-associated complement inhibitors normally protect endothelial cells from autologous complement -- however, these molecules are species-restricted and therefore are ineffective at inhibiting activated xenogeneic complement. To address the pathogenesis of hyperacute rejection in the pig-to-human combination, F1 offspring were generated from a transgenic founder animal that was engineered to express the human terminal complement inhibitor hCD59. High-level cell surface expression of hCD59 was detected in the hearts and kidneys of these transgenic F1 animals, similar to expression levels in human kidney tissue. The hCD59 was expressed on both large vessel and capillary endothelium. Ex vivo perfusion experiments, using human blood as the perfusate, were performed with transgenic porcine hearts and kidneys to evaluate the ability of hCD59 to inhibit hyperacute rejection. These experiments demonstrated that transgenic organs expressing hCD69 resisted hyperacute rejection, as measured by increased organ function for both the hearts and the kidneys, as compared with control pig organs. Hearts from hCD59-expressing animals demonstrated a five-fold prolongation in function compared with controls, 109.8 +/- 20.7 min versus 21.2 +/- 2.9 min (P = 0.164). The hCD59-expressing kidneys also demonstrated significantly prolonged function at 157.8 +/- 27.0 min compared with 60.0 +/- 6.1 min for controls (P = 0.0174). Deposition of C9 neoantigen In the vasculature of porcine organs perfused with human blood was markedly reduced in organs expressing hCD59. These studies demonstrate that C5b-9 plays an important role in hyperacute rejection of a porcine organ perfused with human blood and suggest that donor pigs transgenic for hCD59 may be an integral component of successful clinical xenotransplantation.
对于需要实体器官移植的终末期器官衰竭患者而言，可用供体器官的严重短缺引发了人们对异种移植的浓厚兴趣。成功进行非协调性异种移植的主要障碍是超急性排斥反应。超急性排斥反应是由预先形成的抗体沉积引起的，这些抗体在血管内皮细胞的管腔表面激活补体，导致血管阻塞和移植器官在数分钟至数小时内功能衰竭。内源性膜相关补体抑制剂通常可保护内皮细胞免受自身补体的攻击——然而，这些分子具有物种特异性，因此在抑制激活的异种补体方面无效。为了解决猪到人的组合中超急性排斥反应的发病机制，从一只经过基因工程改造以表达人末端补体抑制剂hCD59的转基因奠基动物产生了F1代后代。在这些转基因F1动物的心脏和肾脏中检测到hCD59在细胞表面高水平表达，类似于人肾组织中的表达水平。hCD59在大血管和毛细血管内皮上均有表达。使用人血作为灌注液，对转基因猪的心脏和肾脏进行了体外灌注实验，以评估hCD59抑制超急性排斥反应的能力。这些实验表明，与对照猪器官相比，表达hCD69的转基因器官抵抗了超急性排斥反应，这通过心脏和肾脏的器官功能增强得以体现。与对照相比，表达hCD59的动物的心脏功能延长了五倍，分别为109.8±20.7分钟和21.2±2.9分钟（P = 0.164）。表达hCD59的肾脏功能也明显延长，为157.8±27.0分钟，而对照为60.0±6.1分钟（P = 0.0174）。在用人血灌注的猪器官脉管系统中，C9新抗原的沉积在表达hCD59的器官中明显减少。这些研究表明，C5b - 9在用人血灌注的猪器官超急性排斥反应中起重要作用，并表明转hCD59基因的供体猪可能是成功进行临床异种移植不可或缺的组成部分。
