Kennedy S P, Rollins S A, Burton W V, Sims P J, Bothwell A L, Squinto S P, Zavoico G B
Department of Vascular Biology, Alexion Pharmaceuticals, Inc., New Haven 06511.
Transplantation. 1994 May 27;57(10):1494-501.
Discordant xenogeneic organ transplantation is a potential solution to the critical shortage of suitable donor organs. However, clinical application of xenotransplantation with physiologically suitable organs such as those from the pig, is currently limited by the lack of agents to prevent antibody and complement-mediated hyperacute rejection of the transplanted organ. We have used retrovirus-mediated gene transfer to express the terminal complement inhibitor protein, human CD59, in neonatal porcine aortic endothelial cells (nPAEC). Human CD59 was constitutively expressed in nPAECs at levels similar to that of native CD59 in human umbilical vein endothelial cells. The protein was tethered to the cell surface by a glycosyl-phosphatidylinositol anchor, as demonstrated by its removal following treatment with phosphatidylinositol-specific phospholipase C. In a model of antibody-dependent complement activation, nPAECs expressing human CD59 were protected from membrane pore formation and cell lysis by complement derived from either human or baboon sera. Conversely, nPAECs expressing CD59 were not protected from lysis by rabbit or dog complement, indicating that recombinant CD59 retained its species-restricted inhibitory activity. Additionally, CD59 expressed on nPAECs inhibited the C5b-9-dependent generation of membrane prothrombinase activity. Collectively, these data establish that stable expression of human CD59 on xenotypic (porcine) endothelial cells renders these cells resistant to both the cytolytic and procoagulant effects of human complement. We propose that expression of recombinant human CD59 on porcine donor organs may prevent complement-mediated lysis and activation of endothelial cells that leads to hyperacute rejection.
异种器官移植不协调是解决合适供体器官严重短缺的一种潜在方法。然而，使用生理上合适的器官（如猪的器官）进行异种移植的临床应用目前受到限制，因为缺乏预防抗体和补体介导的移植器官超急性排斥反应的药物。我们利用逆转录病毒介导的基因转移，在新生猪主动脉内皮细胞（nPAEC）中表达末端补体抑制蛋白人CD59。人CD59在nPAEC中组成性表达，其水平与人类脐静脉内皮细胞中天然CD59的水平相似。该蛋白通过糖基磷脂酰肌醇锚定在细胞表面，用磷脂酰肌醇特异性磷脂酶C处理后可将其去除，证明了这一点。在抗体依赖性补体激活模型中，表达人CD59的nPAEC受到保护，免受来自人或狒狒血清的补体介导的膜孔形成和细胞裂解。相反，表达CD59的nPAEC未受到兔或狗补体的裂解保护，这表明重组CD59保留了其物种特异性抑制活性。此外，nPAEC上表达的CD59抑制了C5b - 9依赖性膜凝血酶原酶活性的产生。总体而言，这些数据表明人CD59在异种（猪）内皮细胞上的稳定表达使这些细胞对人补体的细胞溶解和促凝血作用具有抗性。我们提出，在猪供体器官上表达重组人CD59可能预防补体介导的内皮细胞裂解和激活，从而导致超急性排斥反应。
