Purinergic modulation of the autoimmune vascular phenotype

项目摘要/摘要 这项关于“自身免疫血管表型的嘌呤能调节”的更新是在4年的基础上提出的。 早期研究人员在狼疮、新冠肺炎和抗磷脂综合征领域的发现 (APS)。尽管在后一种疾病中常规使用传统的抗凝剂，但每5名APS患者中仍有1人 预计将经历一次突破性的血栓事件。此外，抗凝血剂几乎不能缓解 慢性闭塞性微血管病变，随着时间的推移损害APS器官。如何对抗抗凝剂- APS的耐药表现尚不清楚。这个项目现在努力使用一位表型较深的患者 队列、选定的体外系统和最相关的动物模型以确定辅助治疗 APS诊所的治疗方法。它的成功完成将进一步揭示中性粒细胞的表型 并将提供对嘌呤能信号转导、中性粒细胞-血小板相互作用、 中性粒细胞代谢在血栓形成事件中起作用。我们的目标是在这笔赠款的下一个周期之前，我们将 已经确定了1-2个最有希望在我们的APS诊所重新使用的候选药物。 APS是血栓形成和晚期妊娠丢失的主要获得性原因。在追求一种机械主义 了解APS中的免疫血栓形成，我们小组是第一个证明中性粒细胞胞外陷阱 (网、染色质缠结和杀微生物蛋白从激活的中性粒细胞通过“网”排出) 是APS相关血栓形成所必需的。自从我们上次竞争提交以来，我们发现 CD73产生的胞外腺苷通过激活表面抑制净释放 腺苷A2a受体(A2AR)，从而促进细胞内cAMP。关键的初步数据说明了这一点 更新证明(I)CD73-A2AR轴抑制了血小板介导的中性粒细胞激活；(Ii) 髓系特异性A2AR基因敲除小鼠的过度血栓形成；(Iii)高活性糖代谢 在APS中性粒细胞中，A2AR激动剂使其正常化；以及(Iv)通过以下方法减轻APS小鼠的血栓形成 注重新陈代谢的干预措施。假设CD73-A2AR-cAMP轴的操纵将 恢复APS中性粒细胞动态平衡。特定目标1将定义嘌呤能信号转导的机制 影响APS患者中性粒细胞和血小板功能。这一目标将首次定义嘌呤能 亲血栓疾病的概况，阐明嘌呤能信号调节的机制 中性粒细胞-血小板通讯，并潜在地确定APS患者中最有可能受益的亚群 抗血小板和/或腺苷受体调节疗法。具体目标2将决定在何种程度上 嘌呤能信号可被用来使APS中性粒细胞代谢正常化。这一目标预计将 提供对内毒素血症代谢需求的新认识，阐明操作策略 中性粒细胞代谢，并确定APS患者中最有可能从这些策略中受益的亚群。

PROJECT SUMMARY/ABSTRACT This proposed renewal of “Purinergic modulation of the autoimmune vascular phenotype” builds upon 4 years of discovery by an early stage investigator in the areas of lupus, COVID-19, and antiphospholipid syndrome (APS). Despite the routine use of traditional anticoagulants in the latter disease, 1 in 5 APS patients is still expected to experience a breakthrough thrombotic event. Furthermore, anticoagulants do little to mitigate the chronic occlusive microangiopathy that damages APS organs over time. How to combat anticoagulant- resistant manifestations of APS is unknown. This project now endeavors to use a deeply-phenotyped patient cohort, selected in vitro systems, and the most relevant animal models to identify adjuvant therapeutic approaches for the APS clinic. Its successful completion will shed additional light on neutrophil phenotypes in APS and will provide a new understanding of the role that purinergic signaling, neutrophil-platelet interactions, and neutrophil metabolism play in thrombotic events. The goal is that by the next cycle of this grant, we will have identified the 1-2 most promising drug candidates for repurposing in our APS clinic. APS is a leading acquired cause of both thrombosis and late-term pregnancy loss. In pursuit of a mechanistic understanding of immunothrombosis in APS, our group was the first to show that neutrophil extracellular traps (NETs, tangles of chromatin and microbicidal proteins expelled from activated neutrophils via “NETosis”) are required for APS-associated thrombosis. Since our last competitive submission, we have found that extracellular adenosine generated by the ectonucleotidase CD73 restrains NET release by activating surface adenosine A2A receptors (A2AR) and thereby boosting intracellular cAMP. Key preliminary data that inform this renewal demonstrate (i) restraint of platelet-mediated neutrophil activation by the CD73-A2AR axis; (ii) exaggerated thrombosis in myeloid lineage-specific A2AR knockout mice; (iii) hyperactive glucose metabolism in APS neutrophils that normalizes with A2AR agonists; and (iv) mitigation of thrombosis in APS mice by metabolism-focused interventions. The hypothesis is that manipulation of the CD73-A2AR-cAMP axis will restore neutrophil homeostasis in APS. Specific Aim 1 will define mechanisms by which purinergic signaling influences neutrophil and platelet function in APS. This Aim will define for the first time the purinergic landscape of a thrombophilic disorder, elucidate mechanisms by which purinergic signaling regulates neutrophil-platelet communication, and potentially identify the subset of APS patients most likely to benefit from antiplatelet and/or adenosine receptor-modulating therapies. Specific Aim 2 will determine the extent to which purinergic signaling can be leveraged to normalize neutrophil metabolism in APS. This Aim is expected to provide a new understanding of the metabolic requirements of NETosis, elucidate strategies for manipulating neutrophil metabolism, and identify the subset of APS patients most likely to benefit from those strategies.