Ex vivo perfusion in a lung box for rehabilitation of donor lungs

描述（由申请人提供）：大多数潜在的供体肺被拒绝移植，因此许多患者在等待合适的供体时死亡。供体肺通常在脑死亡后从个体中取出；然而，在心脏死亡后使用非心脏跳动供体肺（NHBD）重新引起了人们的兴趣。利用NHBD肺的主要挑战是难以评估热缺血期后的功能，这将导致严重的损伤。两种新方法有望极大地扩大NHBD肺的利用：1)在移植前使用“肺盒”进行体外肺灌注（EVLP）评估和恢复肺，以及2)使用腺苷2A受体（A2AR）激动剂恢复肺并预防缺血-再灌注（IR）损伤。本研究将这两种方法结合起来，完善了一种基于肺盒的EVLP方法，以评估和治疗性地修复NHBD肺，以成功移植。我们已经证明了在使用A2AR激动剂EVLP后NHBD猪肺的康复和成功移植，并且我们已经证明了腺苷2B受体（A2BR）拮抗剂可以减轻IR损伤。因此，我们提出的研究将验证这样的假设，即通过使用A2AR激动剂或A2BR拮抗剂进行evlp介导的治疗，NHBD肺可以恢复并成功移植。我们将用三个目标来检验这一假设。Aim 1将使用猪肺移植模型来确定使用A2AR激动剂的EVLP是否可以安全地延长NHBD肺的热缺血和冷缺血时间。目的2将确定EVLP与A2AR激动剂治疗是否将边缘和先前排斥的人类供体肺恢复到可接受的移植状态。目的3将确定含有A2BR拮抗剂的EVLP是否能恢复猪和人的NHBD肺。在每个目标中，我们还将确定EVLP对NHBD肺的康复是否需要抑制NKT细胞活化、上皮细胞活化和中性粒细胞浸润。该项目解决了困扰肺移植的两个主要问题：适合移植的肺太少和移植后由于IR损伤导致的原发性移植物衰竭。如果NHBD肺可以安全康复用于移植，那么就可以消除肺供体短缺。因此，这个项目将提供一种手段，大大扩大供体肺池的规模，并支持临床试验，旨在挽救更多的生命，那些在肺移植等待名单上的患者。

DESCRIPTION (provided by applicant): The majority of potential donor lungs are rejected for transplantation and thus many patients die while waiting for a suitable donor. Donor lungs are typically retrieved from individuals after brain death; however, there is renewed interest in utilizing non-heart- beating donor (NHBD) lungs retrieved after cardiac death. The major challenge for utilization of NHBD lungs is the difficulty in assessing function after a warm ischemic period which results in significant injury. Two novel approaches show promise to greatly expand the utilization of NHBD lungs: 1) use of a "lung box" for ex vivo lung perfusion (EVLP) to assess and rehabilitate lungs prior to transplantation, and 2) use of adenosine 2A receptor (A2AR) agonist to rehabilitate lungs and prevent ischemia-reperfusion (IR) injury. This proposal combines these two approaches to perfect a lung box-based method of EVLP to assess and therapeutically rehabilitate NHBD lungs for successful transplantation. We have demonstrated the rehabilitation and successful transplantation of NHBD porcine lungs after EVLP with an A2AR agonist, and we have demonstrated that an adenosine 2B receptor (A2BR) antagonist attenuates IR injury. Thus our proposed studies will test the hypothesis that NHBD lungs can be rehabilitated for successful transplantation by EVLP-mediated therapy using an A2AR agonist or A2BR antagonist. We will test this hypothesis with three aims. Aim 1 will use a porcine lung transplant model to determine if EVLP with A2AR agonist can safely extend both warm and cold ischemic times of NHBD lungs. Aim 2 will determine if EVLP with A2AR agonist therapy will rehabilitate marginal and previously rejected human donor lungs to an acceptable state for transplantation. Aim 3 will determine if EVLP with A2BR antagonist will rehabilitate porcine and human NHBD lungs. Within each aim, we will also determine if the rehabilitation of NHBD lungs by EVLP entails the inhibition of NKT cell activation, epithelial cell activation and neutrophil infiltration. This project addresses two major problems that plague lung transplantation: far too few suitable lungs for transplant and primary graft failure after transplat due to IR injury. If NHBD lungs can be safely rehabilitated for transplantation, then the lung donor shortage could be eliminated. Thus this project will provide a means to greatly extend the donor lung pool size and support clinical trials aimed at saving many more lives of those patients on the lung transplant waiting list.