Purinergic regulation of Innate Immunity to promote Venous Homeostasis

摘要 深静脉血栓形成（DVT）和继发性肺栓塞（VTE）影响90万人 美国人，每年导致超过60，000人死亡。越来越多的证据支持 炎症和凝血之间的相互作用，其放大了VTE中的血栓-炎症反应。 激活的、受伤的和垂死的细胞释放核苷酸，形成“危险”信号的嘌呤能光环， 血管稳态位于白细胞和内皮细胞表面， 外核苷酸酶，CD 39迅速磷酸化水解ATP和ADP，以消除这些“危险”信号， 促进体内平衡。我们已经发现，CD 39是一个有效的抑制血栓炎症反应， 在DVT中。我们新的初步数据表明，CD 39抑制循环白细胞-血小板相互作用， 限制程序性先天免疫应答的激活，包括炎性小体组装， 中性粒细胞胞外陷阱（NET）形成，血栓生长的关键驱动因素。驱动这一假设的是 CD 39在先天免疫和血栓形成的交叉点提供了一个关键的血管检查点 阻止静脉血栓炎症循环使用独特的细胞谱系（骨髓，中性粒细胞， 内皮）特异性CD 39基因缺失小鼠，以及DVT的互补模型，我们将： 1)阐明CD 39在静脉血栓形成和成熟过程中对细胞募集的作用。这些 实验将确定谱系特异性CD 39对血细胞募集的影响，以及空间动力学 静脉血栓形成过程中它们的相互作用; 2）确定髓系CD 39 防止静脉血栓炎症。这些实验将决定 巨噬细胞和中性粒细胞CD 39与静脉血栓形成的关系。补充性体外和体内研究， 转基因小鼠将阐明CD 39抑制 3）确定CD 39缺陷对微泡的影响 表型、功能和动力学。这些研究将揭示功能 改变整体和谱系特异性CD 39对微泡介导的血栓炎性细胞因子的影响 发信号。这些研究应该产生新的见解，如何外核苷酸酶，作为一个检查点的功能， 在血栓形成和炎症的交叉点，可以用来改善静脉血栓的治疗。 血栓形成

ABSTRACT Deep venous thrombosis (DVT) and secondary pulmonary embolism (together, VTE) affect 900,000 Americans, and result in >60,000 deaths each year. A growing body of evidence supports the concept of crosstalk between inflammation and coagulation which amplifies the thrombo-inflammatory response in VTE. Activated, injured, and dying cells release nucleotides that form purinergic halo of “danger” signals that disrupt vascular homeostasis. Located on the surface of leukocytes and the endothelium, the vascular ectonucleotidase, CD39 rapidly phosphohydrolyzes ATP, and ADP to extinguish these “danger” signals and promote homeostasis. We have found that CD39 is a potent suppressor of the thrombo-inflammatory response in DVT. Our new preliminary data show that CD39 inhibits circulating leukocyte-platelet interactions, and restricts activation of programmed innate immune responses, including inflammasome assembly and neutrophil extracellular trap (NET) formation, key drivers of the growing thrombus. The hypothesis driving this work is that CD39 provides a critical vascular checkpoint at the intersection of innate immunity and thrombosis to arrest the relentless venous thrombo-inflammatory cycle. Using unique cell lineage (myeloid, neutrophil, endothelial)-specific CD39 gene-deleted mice we have generated, and complementary models of DVT, we will: 1) Elucidate the role for CD39 on cellular recruitment during venous thrombogenesis and maturation. These experiments will define the effect of lineage-specific CD39 on blood cell recruitment, and the spatial dynamics of their interactions during venous thrombogenesis; 2) Determine the mechanism(s) by which myeloid CD39 protects against venous thrombo-inflammation. These experiments will determine the contributions of macrophage and neutrophil CD39 to venous thrombosis. Complementary in vitro and in vivo studies with genetically-modified mice will elucidate the molecular signaling processes by which CD39 inhibits inflammasome activation during thrombogenesis; 3) Determine the effect of CD39-deficiency on microvesicle phenotype, function, and kinetics, during venous thrombosis. These studies will reveal the functional consequences of altering global- and lineage-specific CD39 on microvesicle-mediated thrombo-inflammatory signaling. These studies should yield new insights into how an ectonucleotidase that functions as a checkpoint at the intersection of thrombosis and inflammation may be exploited to improve treatments in venous thrombosis.