Role of Spleen educated monocytes in mediating ischemia-reperfusion injury following lung transplant

脾脏单核细胞在介导肺移植后缺血再灌注损伤中的作用

• 批准号: 9765907
• 负责人: Ankit Bharat
• 金额: $ 59.25万
• 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: 2019-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9765907
• 关键词: Affect; Allografting; Alveolar; Alveolar Macrophages; Atlases; Biopsy; Blood Vessels; Bone Marrow; CCL2 gene; CX3CL1 gene; Caring; Cells; Chronic; Clinical; Data; Development; Disease; Donor person; Endothelium; Experimental Designs; Extravasation; Fractalkine; Functional disorder; Genes; Genetic; Genetic study; Herpes zoster disease; Hour; Human; Hypoxemia; Image; Immune; Inflammasome; Injury; Interleukin-1 beta; Intervention; Life; Lung; Lung Transplantation; Lung diseases; Mediating; Membrane; Molecular; Mus; Mutate; Neutrophil Infiltration; Organ; Outcome; Paper; Pathologic; Patient-Focused Outcomes; Patients; Pharmacology; Production; Proteins; Publishing; Pulmonary Inflammation; Receptor Activation; Reperfusion Injury; Reperfusion Therapy; Reporting; Respiratory Failure; Risk Factors; Role; Savings; Signal Pathway; Signal Transduction; Spleen; Splenic Red Pulp; Structure of parenchyma of lung; Syndrome; System; TLR2 gene; Testing; Tight Junctions; Time; Toll-like receptors; Transforming Growth Factor beta; Transgenic Organisms; Translations; Transplantation; Variant; allograft rejection; clinical application; clinical practice; clinically relevant; experimental study; improved; interstitial; lung injury; macrophage; monocyte; mortality; mouse model; neutrophil; novel therapeutics; pathogen; post-transplant; reconstitution; recruit; response; spleen transplantation; two-photon

PROJECT SUMMARY Primary graft dysfunction (PGD) after lung transplantation, resulting from ischemia reperfusion injury (IRI), is the predominant cause of poor lung transplant outcomes. Pathologically, PGD is characterized by neutrophil extravasation into the alveolar space. In murine models of lung transplantation, NETosis of extravasated neutrophils induces irreversible allograft injury. Non-selective depletion of neutrophils can ameliorate PGD, but is not clinically feasible given their importance in pathogen clearance. Accordingly, we have focused on understanding the specific mechanisms that drive neutrophil extravasation into the allograft leading to PGD after lung transplantation. We discovered that after lung transplantation, Ly6ClowCCR2- non-classical monocytes (NCM), retained in the donor lung, and Ly6ChighCCR2+ classical monocytes (CM), recruited to the allograft, are both necessary for the extravasation of neutrophils into the interstitial space and the resulting lung injury. Both NCM and CM produce IL-1β in response to IRI, with differing consequences. We present preliminary data suggesting that IL-1β produced by NCM activates donor alveolar macrophages (AM), inducing their secretion of monocyte chemoattractant protein 1 (MCP-1) which results in recruitment of CM. Our data also demonstrates that CM recruited to the allograft further produce IL-1β in response to signaling through toll-like receptors, which permeabilizes the endothelium by downregulating the tight junction protein, Zona Occludens 2 (ZO-2), to promote neutrophil extravasation. Using a genetic lineage tracing system and heterochronic spleen transplants we reported that CMs originating in the bone marrow receive signals from the spleen necessary for their function in mediating neutrophil extravasation after transplantation revealing the spleen as an active immune organ in this response. We present preliminary data to support our hypothesis that after lung transplantation, IL-1β released by donor NCM induces the secretion of MCP-1 from donor alveolar macrophages, which is necessary for the recruitment of recipient CM primed by splenic red pulp macrophages. This results in sustained IL-β signaling in the allograft that promotes neutrophil extravasation and graft injury. We will test this hypothesis in two aims. Aim 1. To determine whether donor NCM and alveolar macrophage-dependent MCP-1 secretion recruits host splenic CM to mediate neutrophil extravasation after lung transplantation. Aim 2. To determine whether splenic endothelial fractalkine retains CM recruited by TGF-β released from red pulp macrophages to prime the NLRP3 inflammasome. We use causal genetic strategies in mouse models identify disease mechanisms and tie these experiments to applicable therapies that can be tested in humans. In addition, we have taken care to pair our results with unbiased analyses of human lung tissue obtained from biopsies of the donor lung before and at several times after reperfusion during lung transplantation to create a molecular atlas of human ischemia reperfusion injury. These studies will facilitate the rapid translation of our findings to clinical practice.

项目摘要 肺移植后因缺血导致的原发性移植物功能障碍 (PGD) 再灌注损伤（IRI）是肺移植结果不佳的主要原因。从病理学上来说，PGD是 其特征是中性粒细胞外渗至肺泡腔。在小鼠肺移植模型中， 渗出的中性粒细胞的 NETosis 会引起不可逆的同种异体移植损伤。非选择性耗竭中性粒细胞 可以改善 PGD，但鉴于其在病原体清除中的重要性，在临床上不可行。因此， 我们专注于了解驱动中性粒细胞外渗到体内的具体机制 同种异体移植导致肺移植后进行PGD。我们发现肺移植后，Ly6ClowCCR2- 保留在供体肺中的非经典单核细胞 (NCM) 和 Ly6ChighCCR2+ 经典单核细胞 (CM)， 募集到同种异体移植物中，对于中性粒细胞外渗到细胞间隙中都是必需的，并且 由此造成的肺损伤。 NCM 和 CM 都会产生 IL-1β 来响应 IRI，并产生不同的后果。我们 目前初步数据表明 NCM 产生的 IL-1β 激活供体肺泡巨噬细胞 (AM)， 诱导它们分泌单核细胞趋化蛋白 1 (MCP-1)，从而招募 CM。 我们的数据还表明，招募到同种异体移植物中的 CM 响应信号传导进一步产生 IL-1β 通过 Toll 样受体，通过下调紧密连接蛋白使内皮细胞通透， 闭塞带 2 (ZO-2)，促进中性粒细胞外渗。使用遗传谱系追踪系统和 在异时性脾移植中，我们报道了起源于骨髓的 CM 接收来自 脾脏对于移植后介导中性粒细胞外渗的功能是必需的 脾脏作为这种反应中的活跃免疫器官。我们提供初步数据来支持我们的假设 肺移植后，供体NCM释放的IL-1β诱导供体肺泡分泌MCP-1 巨噬细胞，这是招募由脾红髓巨噬细胞引发的受体 CM 所必需的。 这导致同种异体移植物中持续的 IL-β 信号传导，促进中性粒细胞外渗和移植物损伤。 我们将从两个目标来检验这个假设。目的 1. 确定供体 NCM 和肺泡是否 巨噬细胞依赖性 MCP-1 分泌招募宿主脾 CM 介导中性粒细胞外渗 肺移植后。目标 2. 确定脾内皮分形蛋白是否保留 CM 被红髓巨噬细胞释放的 TGF-β 招募来启动 NLRP3 炎性体。我们使用 小鼠模型中的因果遗传策略确定了疾病机制并将这些实验与 可以在人体上进行测试的适用疗法。此外，我们还小心地将我们的结果与 对供体肺活检之前和多次获得的人肺组织进行公正的分析 肺移植再灌注后创建人体缺血再灌注损伤分子图谱。 这些研究将有助于我们的研究结果快速转化为临床实践。