Inhibition of platelet-leukocyte interactions to treat TRALI

描述（由申请人提供）：本申请涉及广泛的挑战领域（04）临床研究和特定的挑战主题04-HL-103评估白细胞与血小板、红细胞和内皮细胞相互作用在心脏、肺和血液疾病发病机制中的作用。 输血相关急性肺损伤（TRALI）是报告给FDA的输血相关发病率和死亡率的主要原因，是一种临床综合征，在输血后6小时内发生急性肺损伤。尽管其病理生理学仍不清楚，但已建议激活多形核中性粒细胞（PMNs）的抗体和/或生物活性脂质会在具有易感促炎事件的患者中引发该综合征。我们的初步研究表明，血小板-白细胞相互作用在疾病中起着关键作用。更具体地，由E-选择素与在PMN上表达的E-选择素配体-I（ESL-1）的接合产生的内皮信号诱导在爬行的PMN的前缘处的整合素Mac-1的活化，允许血小板的捕获，这进而通过活性氧物质（ROS）的产生导致损伤。目前的挑战是进行临床前研究，并开发新的方法来测定这种类型的延迟PMN激活。拟议的翻译研究将导致临床试验，测试新的拮抗剂对TRALI涉及的粘附分子的安全性和有效性。在具体目标1中，我们评估了新型选择素拮抗剂GMI-1070在已建立的TRALI小鼠模型中的疗效。在特定目标2中，我们将开发TRALI的人源化模型，其中小鼠通过在IL-2 r共同γ链缺陷的免疫缺陷NOD/SCID小鼠中移植脐带血来源的造血干细胞和祖细胞来携带循环的人PMN。我们将通过注射抗HNA-2a诱导TRALI，该抗HNA-2a先前显示在大鼠离体模型中产生肺损伤。我们将使用多通道荧光活体显微镜（MECHANISM）评估该抗体的给药是否诱导血小板-白细胞相互作用和ROS生成。我们将确定GMI-1070给药对肺损伤和血小板-白细胞相互作用的影响。在具体目标3中，我们将使用血小板复合物的基于流动的成像与PMN的极化前缘开发PMN激活的二次波的临床相关生物标记物。该试验将提供一种新的生物学终点，以评估PMN激活和抗炎药物的疗效在临床试验中。 公共卫生相关性：初步研究表明，血小板-白细胞相互作用在TRALI的发病机制中起关键作用。在本提案中，我们将进行转化研究并开发新工具，为治疗和/或预防TRALI的临床试验做准备。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (04) Clinical Research, and the specific Challenge Topic 04-HL-103 Assess the role of leukocyte interaction with platelets, erythrocytes, and endothelium in the pathogenesis of heart, lung, and blood diseases. Transfusion-related acute lung injury (TRALI), the main cause of transfusion-related morbidity and mortality reported to the FDA, is a clinical syndrome in which acute lung injury occurs within 6 hours of a blood transfusion. Although its pathophysiology remains unclear, antibodies and/or bioactive lipids activating polymorphonuclear neutrophils (PMNs) have been suggested to initiate the syndrome in patients with a predisposing pro-inflammatory event. Our preliminary studies suggest that platelet-leukocyte interactions play a key role in the disease. More specifically, endothelial signals emerging from the engagement of E- selectin with E-selectin ligand-1 (ESL-1) expressed on PMNs, induced the activation of the integrin Mac-1 at the leading edge of crawling PMNs, allowing the capture of platelets which, in turn, led to injury through the production of reactive oxygen species (ROS). The present challenge is to conduct pre-clinical studies and develop novel methods to assay this type of delayed PMN activation. The proposed translational studies will lead to a clinical trial testing the safety and efficacy of novel antagonists against adhesion molecules involved in TRALI. In Specific Aim 1, we evaluate the efficacy of GMI-1070, novel selectin antagonist, in an established mouse model of TRALI. In Specific Aim 2, we will develop a humanized model of TRALI in which mice harbor circulating human PMNs by transplantation of cord blood-derived hematopoietic stem and progenitor cells in immunodeficient NOD/SCID mice deficient in the IL-2r common gamma chain. We will induce TRALI by injection of an anti-HNA-2a, which was previously shown to produce lung injury in a rat ex vivo model. We will evaluate using multichannel fluorescence intravital microcopy (MFIM) whether the administration of this antibody induces platelet-leukocyte interactions and ROS generation. We will determine the effect of GMI-1070 administration on lung injury, and platelet-leukocyte interactions by MFIM. In Specific Aim 3, we will develop a clinically relevant biological marker of the secondary wave of PMN activation using flow-based imaging of platelet complexes with the polarized leading edge of PMNs. This assay will provide a novel biological end-point to assess PMN activation and the efficacy of anti-inflammatory drugs in clinical trials. PUBLIC HEALTH RELEVANCE: Preliminary studies suggest that platelet-leukocyte interactions play a key role in the pathogenesis of TRALI. In this proposal, we will perform translational studies and develop new tools in preparation of a clinical trial to treat and/or prevent TRALI.