Donor nonclassical monocytes initiate lung injury following transplantation

供体非经典单核细胞在移植后引发肺损伤

• 批准号: 10093127
• 负责人: Ankit Bharat
• 金额: $ 55.12万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10093127
• 关键词: Acute; Adoptive Transfer; Affect; Allografting; Alveolar; Antibodies; Antigens; Biology; Blood Vessels; CX3CL1 gene; CX3CR1 gene; CXCL2 gene; Chemotactic Factors; Chronic; Clinical; Contralateral; Data; Development; Distant; Donor person; Endothelial Cells; Endothelium; Extravasation; Fractalkine; Functional disorder; Genetic; Growth; Hour; Human; Hypoxemia; IL1R1 gene; Inflammasome; Injury; Integrins; Interleukin-1; Interleukin-1 beta; Lead; Leukocytes; Lung; Lung Transplantation; Lymphocyte; Mediating; Membrane; Molecular; Mus; Mutate; NR4A1 gene; Neutrophil Infiltration; Organ; Outcome; Pathway interactions; Patient-Focused Outcomes; Patients; Perfusion; Pharmacology; Prevention; Production; Publishing; Pulmonary Inflammation; Reperfusion Injury; Reperfusion Therapy; Reporting; Resistance; Respiratory Failure; Risk Factors; Role; Signal Pathway; Signal Transduction; Solid; Specificity; Syndrome; System; TLR2 gene; Techniques; Therapeutic; Tight Junctions; Tissues; Toll-like receptors; Toxic effect; Transcript; Transplantation; Up-Regulation; Vascular Permeabilities; cadherin 5; clinical application; experience; experimental study; improved; insight; lung development; lung injury; lung ischemia; migration; monocyte; mortality; mouse model; neutrophil; novel; pathogen; post-transplant; preservation; pulmonary function; reconstitution; recruit; success; transplantation therapy

The indications for lung transplantation have expanded significantly, resulting in a clinical growth of over 50% in the last decade. However, the survival following lung transplant is the worst compared to other solid organs with only 80% and 50% of patients alive at 1 and 5 years, respectively. Primary graft dysfunction (PGD), resulting from ischemia-reperfusion injury, affects over 50% of recipients within 24 hours of transplantation and has emerged as the most important risk factor for both short-term mortality as well as long-term graft loss from chronic rejection. As such, therapies directed to ameliorate PGD have the highest potential for improving lung transplant outcomes. Prior reports have demonstrated that recruitment and extravasation of neutrophils into the allograft is necessary for the development of PGD. Depleting neutrophils can ameliorate PGD, but is not clinically feasible given their importance in pathogen clearance. Accordingly, we have focused on understanding the mechanisms that drive neutrophil recruitment to the lung following transplantation. We discovered that orphan nuclear receptor (NR4A1)-dependent non-classical monocytes (NCM), characterized by CD14dimCD16++ in humans and Ly6ClowCX3CR1highCCR2- in mice, are bound to the pulmonary endothelium via a leukocyte integrin (lymphocyte factor associated antigen-1) and retained in the donor lungs despite the current techniques for organ perfusion. Following murine and human lung transplant, activated donor-derived NCM mediate neutrophil recruitment and extravasation into the allograft through mechanisms that remain unknown. Our published and preliminary data suggest that activation of toll-like receptors in donor-derived NCM leads to the production of neutrophil chemoattractant, macrophage inflammatory protein 2 (MIP-2). The donor NCM also release IL-1 and contribute to enhanced vascular permeability in the allograft. Importantly, using a genetic lineage tracing system we found that donor-derived NCM also migrate to distant organs after transplant where they recruit neutrophils. Collectively, these data support our hypothesis that donor-derived NCM are activated following lung ischemia-reperfusion, drive neutrophil influx into the allograft, and promote secondary injury to distant organs. We have developed a model of murine vascularized orthotopic lung transplantation where lungs from NR4A1-deficient donor mice, which selectively lack NCM, can be reconstituted with fluorescent wild-type or genetically mutated NCM to study the signaling pathways in donor-derived NCM and their contribution to lung IRI. Accordingly, we will dissect the molecular mechanisms underlying NCM-mediated injury in the allograft and bystander tissues. We will determine: 1) The toll-like receptors responsible for the activation of donor NCM, 2) Mechanisms through which donor NCM migrate to distant organs and mediate bystander injury, 3) The role of inflammasome-dependent production of IL-1 by NCM in mediating neutrophil extravasation. Through these experiments, we will identify pathways that could be clinically targeted, prior to transplantation, to ameliorate PGD without causing recipient toxicity.

肺移植的适应症已大大扩展，导致临床增长超过50％ 在过去的十年中。但是，与其他固体器官相比，肺移植后的生存最差 在1和5年中，只有80％和50％的患者活着。一级移植功能障碍（PGD）， 由缺血 - 重新灌注损伤引起的，在移植后的24小时内影响超过50％的受体 已成为短期死亡率以及长期移植物的最重要危险因素 慢性拒绝。因此，针对改善PGD的疗法具有改善肺的最高潜力 移植结果。先前的报告表明，中性粒细胞招募和渗出 截形对于开发PGD是必要的。耗尽嗜中性粒细胞可以改善PGD，但不是 鉴于它们在病原体清除率中的重要性。根据，我们专注于 了解移植后促进中性粒细胞募集到肺部的机制。我们 发现孤儿核接收器（NR4A1）依赖性非古典单核细胞（NCM）的特征是 人类中的CD14DIMCD16 ++在小鼠中与Ly6clowcx3cr1highccr2-绑定到肺部内皮 通过白细胞整联蛋白（淋巴细胞因子相关抗原1），并保留在供体肺Dospite中 当前的器官灌注技术。跟随鼠和人类肺移植，激活的供体衍生 NCM通过仍然存在的机制介导嗜中性粒细胞的募集和渗出到同种异体移植物中 未知。我们已发布的初步数据表明，在供体衍生中激活类似收费的接收器 NCM导致产生中性粒细胞趋化剂，巨噬细胞炎症蛋白2（MIP-2）。这 供体NCM还释放IL-1，并有助于同种异体移植中的血管通透性增强。重要的是， 使用遗传谱系追踪系统，我们发现供体衍生的NCM也迁移到遥远的器官之后 他们招募嗜中性粒细胞的移植。总的来说，这些数据支持我们的假设，即捐助者衍生 肺部缺血 - 再灌注后，NCM被激活，将中性粒细胞影响到同种异体移植物中，并促进 远处器官的继发伤害。我们已经开发了一种鼠血管矫形器肺的模型 从选择性缺乏NCM的NR4A1缺乏供体小鼠的肺的移植可以是 用荧光野生型或遗传突变的NCM重组以研究信号通路 捐助者衍生的NCM及其对肺IRI的贡献。根据，我们将剖析分子 NCM介导的损伤的机制在同种异体移植和旁观者组织中。我们将确定：1） 负责供体NCM激活的收费类受体，2）供体NCM的机制 迁移到遥远的器官并介导旁观者伤害，3） NCM介导嗜中性粒细胞渗出的IL-1。通过这些实验，我们将确定 可以在移植前临床靶向以减轻PGD，而不会引起受体毒性。