An additive solution to expand the lung transplant organ pool

项目摘要 肺移植领域的主要挑战是健康供体肺（移植物）的可用性低， 移植后供体肺的损伤这些是由于炎症和氧化损伤引起的， 在移植物储存期间。在用于改善肺可用性和 移植结果是短的储存时间（包括< 3小时，在灌注下储存，即离体肺 灌注或EVLP回路，低温储存，以及使用各种抗氧化剂溶液）和 移植后免疫抑制治疗。其中，EVLP单独显示承诺，但它是成本- 禁止使用，并且在肺获取部位通常无法使用。免疫抑制疗法，虽然 部分有效会使移植受体衰弱。 Peroxitech LLC建议使用一种替代策略来阻断最早的信号传导事件， 在肺储存期间触发，进而导致炎症和损伤。查特吉集团的作品 已经表明肺血管壁对与肺储存相关的血流停止作出响应， 激活内皮信号级联，导致NADPH氧化酶2（NOX 2）的激活和反应性 氧物种（ROS）的产生。该小组还报道了磷脂酶A2（PLA 2）活性的变化。 过氧化物氧还蛋白6酶在NOX 2活化中至关重要。最近，Peroxitech公司发现了一种九种氨基酸 肽序列（PIP-2），其可以阻断Prdx 6的PLA 2活性，从而减少NOX 2活化， ROS产生。初步数据显示，小鼠肺中储存的9种肽氨基酸显著 减少ROS的产生。肺中ROS的产生已被充分证实会引起炎症的活化， 抗原呈递级联反应是募集先天性（多形核中性粒细胞或 PMN）和来自接受者的适应性免疫细胞（T淋巴细胞）。中性粒细胞粘附于血管壁， 新移植的肺（移植物），迁移和释放氧化剂，导致移植物损伤，同时激活T- 淋巴细胞驱动移植组织的溶解。Peroxitech公司提出通过阻断供体肺中的 在与PIP-2（体外）一起储存期间的信号，使得PMN募集和T细胞活化（两者都是 其是ROS依赖性的）在移植后被最小化。为此，将评价PIP-2作为肺保护剂 溶液我们将在目的1）评价PIP-2制剂在供体肺保护中的有效性， 2）评价PIP-2作为保存液在小鼠肺移植中的作用 结果。如果获得的数据显示在肺储存期间PIP-2的使用导致肺功能的显著降低， 炎症，损伤和改善的肺功能，移植后，我们将能够进行到第二阶段 在离体人类供体肺中对这种药物进行全面的临床和分析评估， 批准

PROJECT SUMMARY Major challenges in the field of lung transplantation are the low availability of healthy donor lungs (graft) and the damage to donor lungs post-transplant. These arise due to inflammation and oxidative damage initiated during the graft storage period. Among the multiple strategies employed to improve lung availability and transplant outcome are short storage times (comprising of < 3 h, storage under perfusion i.e. ex vivo lung perfusion or EVLP circuit, hypothermic storage, and the use of various antioxidant solutions) and immunosuppression therapy post-transplant. Of these, EVLP alone shows promise; however it is cost- prohibitive and often unavailable at the point of site of lung procurement. Immunosuppressive therapy, though partially effective is debilitating for the transplant recipient. Peroxitech LLC proposes to use an alternate strategy of blocking the earliest signaling events that are triggered during lung storage and that in turn lead to inflammation and injury. Work from the Chatterjee group has shown that pulmonary vascular wall responds to stop of blood flow associated with lung storage by activating an endothelial signaling cascade that leads to activation of NADPH oxidase 2 (NOX2) and reactive oxygen species (ROS) production. This group also reported that the phospholipase A2 (PLA2) activity of the enzyme Peroxiredoxin 6 is crucial in NOX2 activation. Recently, Peroxitech discovered a nine amino-acid peptide sequence (PIP-2) that can block the PLA2 activity of Prdx6 and thus diminish NOX2 activation and ROS production. Preliminary data shows that murine lungs stored in the 9 peptide aminoacid significantly reduced ROS production. ROS generation in lungs is well established to cause activation of inflammation and antigen presentation cascades which are signals for recruitment of innate (polymorphonuclear neutrophils or PMN) and adaptive immune cells (T lymphocytes) from the recipient. PMN adhere to the vessel wall of the newly transplanted lung (graft), transmigrate and release oxidants causing injury to the graft while activated T- lymphocytes drive lysis of the graft tissue. Peroxitech proposes to pre-“treat” donor lungs by blocking the signals during storage with PIP-2 (outside the body) such that PMN recruitment and T cell activation (both of which are ROS dependent) after transplant, is minimized. For this will evaluate PIP-2 as a lung preservation solution. We will in Aim 1) Evaluate PIP-2 formulations for effectivity in donor lung protection with increasing storage times and Aim 2) Evaluate the effect of PIP-2 as a preservation solution in murine lung transplant outcomes. If data obtained show that PIP-2 usage during lung storage leads to a significant reduction in inflammation, injury and an improved lung function, post-transplant, we will be enabled to proceed to Phase II with a full clinical and analytical evaluation of this agent in isolated human donor lungs, for an eventual FDA approval.