Nanoparticle Targeting of Neutrophil Subpopulations in Inflammatory Lung Injury

项目总结/摘要 急性呼吸窘迫综合征是由严重失调的免疫反应引起的，免疫反应导致肺血管损伤和富含蛋白质的炎症反应。 水肿中性粒细胞（PMN）的过度活化是肺损伤的主要原因。实验性 脓毒症和脓毒症患者，一些中性粒细胞被强烈激活并被隔离在肺中，而另一些则通过 通过肺微血管系统畅通无阻，并作为重要的宿主防御细胞发挥作用。之前的发现 提示PMNs可能以不同的亚群和不同的激活阶段存在。的概念 中性粒细胞的异质性提出了一种可能性，即激活的中性粒细胞的子集可能有助于适应不良， 炎症反应并导致肺损伤。我们发现有一部分中性粒细胞 内化的100 nm白蛋白纳米颗粒（ANP）。我们的支持数据显示， 在小鼠实验性脓毒症中显着增加，并且它们被证明是发展所必需的 炎症性肺损伤我们还将药物与ANP结合，以将其精确递送到这些PMN中。这些 结果提出了几个基本的问题：什么是这种中性粒细胞的人口的性质？是否有相关的 人口在人类？它们的功能是什么，它们的起源是什么？ANP的发病机制是什么 内化？这些细胞介导肺损伤吗？ANP能否将药物输送到PMN中， 疾病的过程？我们将通过描述以下功能来解决这些PMNs： CD 11b高CD 16 + CD 45高ANP高PMN亚群，与对照CD 11b高CD 16 + CD 45高ANP低PMN相反 介导炎症性肺损伤（目的1）。在这里，我们将测试假设，即ANPhigh PMNs是 在功能上不同于ANPlow PMN，并且前者在介导肺损伤中是至关重要的。接下来我们就 确定不同PMN亚群中的差异β2整合素信号传导及其在 介导肺损伤（目的2）。在这里，我们将测试的假设，β2整合素和下游信号 与ANPlow PMN相比，在ANPlow PMN中， 需要炎性肺损伤最后，我们将定义的起源，命运，和表型异质性， 中性粒细胞介导肺损伤（目的3）。在这里，RNA-Seq分析迄今已揭示了不同的趋化因子 受体作为肺中ANP高PMN的标志物，我们将利用这些信息来分离该亚群，以进一步 表征它们并评估它们在介导肺损伤中的功能作用。我们还将定义时间- 在炎症活化过程中，ANP高与ANP低PMN的依赖性转录组学特征和网络， 评估它们的微分特性。因此，一起研究将不仅定义一个人口有毒伤害促进 而且还有望发现新的治疗靶点，以逆转炎症性肺 损伤

PROJECT SUMMARY / ABSTRACT ARDS results from a severely dysregulated immune response that leads to lung vascular injury and protein-rich edema. Excessive activation of neutrophils (PMNs) is a primary cause of the lung damage. In experimental sepsis and septic patients, some PMNs are intensely activated and sequestered in lungs while others pass through the lung microvasculature unimpeded and function as essential host-defense cells. Previous findings suggest that PMNs might exist as various subsets and in different stages of activation. The concept of heterogeneity of PMNs raises the possibility that a subset of activated PMNs may contribute to a maladaptive inflammatory response and be responsible for lung injury. We found that a subset of PMNs specifically internalized 100 nm albumin nanoparticles (ANPs). As our Supporting Data show this population of PMNs increased significantly in experimental sepsis in mice and they were shown to be essential for the development of inflammatory lung injury. We also conjugated drugs to ANP for their precise delivery into these PMNs. These results raise several fundamental questions: What is the nature of this PMN population? Is there a related population in humans? What is their function and what is their origin? What is the mechanism of ANP internalization? Do these cells mediate lung injury and can ANP deliver drugs into this PMN population to reverse the course of the disease? We will address these PMNs by characterizing the function of CD11bhighCD16+CD45highANPhigh PMN subset as opposed to control CD11bhighCD16+CD45highANPlow PMNs in mediating inflammatory lung injury (Aim 1). Here we will test the hypothesis that ANPhigh PMNs are functionally distinct from ANPlow PMNs and that the former are crucial in mediating lung injury. Next, we will determine differential β2 integrin signaling in the distinct PMN sub-populations and their role in mediating lung injury (Aim 2). Here we will test the hypothesis that β2 integrins and downstream signaling pathway are hyper-activated in ANPhigh PMNs compared to ANPlow PMNs and differential PMN signaling is required inflammatory lung injury. Finally, we will define the origin, fate, and phenotypic heterogeneity of PMNs mediating lung injury (Aim 3). Here, RNA-Seq profiling has thus far revealed distinct chemokine receptors as markers of ANPhigh PMNs in lungs, and we will use this information to isolate this subset to further characterize them and assess their functional role in mediating lung injury. We will also define the time- dependent transcriptomic profiles and networks of ANPhigh vs. ANPlow PMNs during inflammatory activation to assess their differential properties. Thus, together studies will not only define a population toxic injury-promoting population of PMN but also hopefully identify new therapeutic targets to reverse the course of inflammatory lung injury.