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: 10318938
• 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/10318938
• 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; Hypoxemic Respiratory Failure; 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; 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; graft dysfunction; 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.

肺移植的适应症显著扩大，导致临床增长率超过50%。 在过去的十年里。然而，与其他实体器官相比，肺移植的存活率是最差的。 术后1年和5年分别只有80%和50%的患者存活。原发性移植物功能障碍(PGD)， 由于缺血再灌注损伤，超过50%的受者在移植后24小时内受到影响， 已经成为短期死亡率和长期移植物损失的最重要的风险因素 慢性排斥。因此，针对改善PGD的治疗对改善肺部的潜力最大。 移植结果。先前的报告表明，中性粒细胞的募集和外渗进入 同种异体移植物是PGD发生发展所必需的。耗尽中性粒细胞可以改善PGD，但不是 考虑到它们在病原体清除中的重要性，临床上是可行的。因此，我们将重点放在 了解移植后中性粒细胞重新聚集到肺的机制。我们 发现孤儿核受体(NR4A1)依赖非经典单核细胞(NCM)，其特征 由CD14dimCD16++在人和Ly6ClowCX3CR1HighCCR2-在小鼠体内，均与肺内皮细胞结合 通过白细胞整合素(淋巴细胞因子相关抗原-1)并保留在供体肺中，尽管 目前的器官灌流技术。在小鼠和人肺移植后，活化的供体来源 NCM通过仍然存在的机制介导中性粒细胞募集和外渗进入同种异体移植物 未知。我们已发表的和初步的数据表明，供者来源的Toll样受体的激活 NCM导致中性粒细胞趋化因子巨噬细胞炎性蛋白2(MIP-2)的产生。这个 供体神经干细胞还释放IL-1，促进同种异体移植物的血管通透性增强。重要的是 使用遗传谱系追踪系统，我们发现供者来源的NCM也在 在他们招募中性粒细胞的地方进行移植。总的来说，这些数据支持了我们的假设，即供体来源 肺缺血再灌注后NCM被激活，驱动中性粒细胞流入同种异体移植物，并促进 远处器官的继发性损伤。我们建立了一种带血管的小鼠原位肺模型。 选择性缺乏NCM的NR4A1缺陷供体小鼠的肺可以进行移植 重组荧光野生型或基因突变的NCM以研究其信号转导途径 供体来源的NCM及其对肺IRI的贡献。因此，我们将剖析分子 NCM介导的同种异体移植物和旁观者组织损伤的机制。我们将确定：1) Toll样受体负责激活供体NCM，2)供体NCM通过 迁移到远处的器官和介导旁观者的损伤，3)炎症依赖的产生的作用 流式细胞仪检测IL-1在中性粒细胞外渗中的作用通过这些实验，我们将确定 可在移植前用于临床靶向，在不引起受体毒性的情况下改善PGD。