Treatment of Transplant Reperfusion with an Anti-CD47 Antibody

用抗 CD47 抗体治疗移植物再灌注

• 批准号: 7746004
• 负责人: PAMELA Ann TOY-MANNING
• 金额: $ 20.32万
• 依托单位: VASCULOX, INC.
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7746004
• 关键词: Address; Animal Model; Anti-Inflammatory Agents; Anti-inflammatory; Antibodies; Apoptosis; Bile fluid; Binding; Biological Assay; Biological Availability; Biological Preservation; Blood Circulation; Blood Platelets; Blood Pressure; Blood Vessels; Blood flow; Brain; CD47 gene; Caspase; Cells; Cleaved cell; Clinic; Cryopreservation; Cyclic Nucleotides; Data; Endothelium; Enzymes; Excision; Flushing; Functional disorder; Genetic; Goals; Harvest; Heart; Hemorrhage; Hindlimb; Hypoxia; In Situ Nick-End Labeling; Infection; Inflammation; Inflammation Mediators; Ischemia; Kidney; Knock-out; Life; Ligands; Liver; Longevity; Lung; Malignant Neoplasms; Mechanics; Modeling; Modern Medicine; Monoclonal Antibodies; Mus; Myocardial Infarction; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Operative Surgical Procedures; Organ; Organ Donor; Organ Harvestings; Organ Transplantation; Outcome; Patients; Perfusion; Phase; Platelet Activation; Process; Production; Protocols documentation; Rattus; Reactive Oxygen Species; Reperfusion Injury; Reperfusion Therapy; Respiratory Burst; Rewarming; Shock; Signal Transduction; Site; Solid; Staining method; Stains; Stroke; System; Thrombosis; Thrombospondin 1; Tissues; Transplantation; Transplanted tissue; Trauma; United States National Institutes of Health; Vascular System; Vascular blood supply; Warm Ischemia; Work; cytokine; efficacy testing; fighting; hemodynamics; improved; inhaled nitric oxide; killings; liver transplantation; mouse model; novel strategies; preconditioning; public health relevance; receptor; success; vasoconstriction; wound

DESCRIPTION (provided by applicant): Organ transplantation is one of the great success stories of modern medicine. However, the supply of suitable organs lags far behind the need and many patients die while waitlisted for organs. Current practice involves "donor preconditioning" to stabilize organs and tissues for transplant in attempts to increase the supply of donor organs acceptable for transplantation. A key goal of preconditioning is to reduce the damage inflicted by ischemia-reperfusion injury (IRI) that occurs when the ischemic/ hypoxic organ is connected to the recipient's circulation. This storm of reactive oxygen species, inflammatory mediators and prothombotic factors threatens to kill the new organ and wreaks havoc upon the recipient as well. Current work indicates that enhancing the low levels of nitric oxide (NO) produced by eNOS and nNOS can dramatically improve IRI and transplant outcomes. The founders of Vasculox, Inc have discovered a receptor, CD47, that continually opposes the action of beneficial NO in all vascular cells. Knocking out CD47 in mice or blocking CD47 with a monoclonal antibody (mAb) results in enhanced tissue perfusion in a number of surgical ischemia models and protection from IRI in both liver and hindlimb models. In this phase one proposal, we seek to perform proof of concept studies in a well-characterized rat model of liver transplantation, testing the efficacy of anti-CD47 mAb treatment of the donor liver to protect it from IRI. Here we will compare the best case scenario in which anti-CD47 mAb is administered to the donor rat and maintained throughout liver harvest, cold storage and reperfusion, with the worst case of no CD47 blockade. In our protocol, the heart-beating donor rat will be treated with anti-CD47 mAb, the liver harvested and flushed with anti-CD47 mAb, subjected to cold storage ischemia and then rewarmed in the presence of mAb under controlled conditions of machine reperfusion. After a fixed interval of reperfusion, levels of released soluble liver enzymes and inflammatory mediators will be assayed, tissue taken for assays of ATP and cyclic nucleotides and the liver fixed for quantitative cytologic analysis and histochemical staining for the distribution of the anti-CD47 mAb and apoptosis (TUNEL and cleaved caspase). A simplified nonheart-beating donor model will also be performed when a period of warm ischemia is interposed between mAb administration and organ harvest. The data obtained in this phase I project will establish proof of concept for anti-CD47 mAb therapy in this liver transplant model. Phase II will address the "real world" situation of transplantation of treated or control livers into living recipients that can then be treated (or not) with the anti-CD47 mAb. While we have chosen to focus here on the liver model, we anticipate that anti-CD47 therapy will be of benefit in the transplantation of other organs (heart, kidney, lung, etc) as well as in surgeries involving organ resection for trauma and cancer and, potentially, in myocardial infarction and stroke. PUBLIC HEALTH RELEVANCE: The founders of Vasculox Inc, have discovered a regulatory receptor, CD47, that inhibits nitric oxide signaling in all vascular tissues. Nitric oxide provides many beneficial effects in the vascular system, including limiting ischemia-reperfusion injury. Therefore blocking CD47 and removing nitric oxide inhibition improves ischemia-reperfusion injury and holds promise as a means to improve the condition of organs destined for transplant and to control the damage to the recipient caused by ischemia reperfusion injury. Vasculox is developing a monoclonal antibody that targets CD47 and in this project aims to test the efficacy of such an antibody in a rat model of organ harvest, transport and reperfusion.

描述（申请人提供）：器官移植是现代医学的伟大成功故事之一。然而，合适的器官供应远远落后于需求，许多患者在等待器官时死亡。目前的做法涉及“供体预处理”，以稳定用于移植的器官和组织，试图增加可用于移植的供体器官的供应。预处理的一个关键目标是减少缺血/缺氧器官与受体循环连接时发生的缺血-再灌注损伤（IRI）造成的损害。这种活性氧、炎症介质和促炎因子的风暴有可能杀死新器官，并对受体造成严重破坏。目前的研究表明，提高eNOS和nNOS产生的低水平一氧化氮（NO）可以显着改善IRI和移植结果。Vasculox公司的创始人发现了一种受体CD 47，它在所有血管细胞中持续对抗有益的NO的作用。敲除小鼠中的CD 47或用单克隆抗体（mAb）阻断CD 47导致在许多手术缺血模型中增强的组织灌注以及在肝脏和后肢模型中保护免于IRI。在这个第一阶段的提案中，我们试图在一个充分表征的大鼠肝移植模型中进行概念验证研究，测试抗CD 47 mAb治疗供体肝脏以保护其免受IRI的有效性。在这里，我们将比较最佳情况，其中将抗CD 47 mAb给予供体大鼠并在整个肝脏收获、冷藏和再灌注过程中维持，最差情况为无CD 47阻断。在我们的方案中，心脏跳动的供体大鼠将用抗CD 47 mAb处理，收获肝脏并用抗CD 47 mAb冲洗，进行冷藏缺血，然后在mAb存在下在受控的机器再灌注条件下复温。在固定的再灌注间隔后，将测定释放的可溶性肝酶和炎症介质的水平，取组织进行ATP和环核苷酸测定，并固定肝脏进行定量细胞学分析和组织化学染色，以确定抗CD 47 mAb和细胞凋亡的分布（TUNEL和裂解的半胱天冬酶）。当在mAb给药和器官收获之间插入一段时间的热缺血时，也将进行简化的无心跳供体模型。在该I期项目中获得的数据将在该肝移植模型中建立抗CD 47 mAb治疗的概念证明。第二阶段将解决“真实的世界”的情况下，移植治疗或对照肝脏到生活受体，然后可以治疗（或不治疗）与抗CD 47单克隆抗体。虽然我们选择将重点放在肝脏模型上，但我们预计抗CD 47治疗将有利于其他器官（心脏、肾脏、肺等）的移植以及涉及创伤和癌症器官切除的手术，并可能有利于心肌梗死和中风。公共卫生关系：Vasculox公司的创始人发现了一种调节受体CD 47，它抑制所有血管组织中的一氧化氮信号传导。一氧化氮在血管系统中提供许多有益的作用，包括限制缺血再灌注损伤。因此，阻断CD 47和去除一氧化氮抑制改善缺血-再灌注损伤，并有望作为改善预定用于移植的器官的状况和控制由缺血再灌注损伤引起的对受体的损害的手段。Vasculox正在开发一种靶向CD 47的单克隆抗体，该项目旨在测试这种抗体在大鼠器官采集，运输和再灌注模型中的功效。