Modulation of neutrophil function through emperipolesis

项目摘要 近50年来，人们已经知道，中性粒细胞定期出现在巨核细胞（MK）， 组织学现象称为帝国主义。利用我们开发的新工具在体外研究这一过程 在体内，我们发现，在实验性炎症应激中， 一种鼠系统。中性粒细胞渗透到MK细胞质中，提供其表面的一部分 在出现活力和完整之前，膜到血小板。我们的初步数据显示， 在帝国主义期间增加MK衍生的外泌体，并以增强的迁移能力出现。基础上 这些结果，我们探讨了这一假设，即帝国是一种新的细胞间相互作用， 中性粒细胞的功能。 我们在两个独立但互补的目标中测试这一假设。在目标I中，我们研究了 本发明涉及MK外泌体，特别是MK外泌体对中性粒细胞效应子功能、代谢和体内 在嗜中性粒细胞依赖性K/BxN血清转移关节炎中的迁移。在Aim II中，我们采用了整体安装3D 骨髓成像、双光子体内显微镜检查、特异性MK缺失和潜在的帝国主义 封锁测试的可能性，帝国主义代表了一个定量的重要途径， 中性粒细胞从体内骨髓中排出，包括在实验性关节炎中。 总之，这些研究将确定一种新的形式的合作之间的MK和中性粒细胞，调节 中性粒细胞参与健康和疾病的能力。更广泛地说，根据我们最近的 由于MKs被鉴定为关节炎中IL-1的来源，这些研究继续发展对 MK和中性粒细胞参与全身性炎症性疾病。这些"高风险、高回报" 对一个以前被忽视的生物过程的研究，在哺乳动物物种中广泛保守， 这是一个扩展研究帝国主义作为一种新的细胞中细胞现象的阶段。

Project Summary For almost 50 years it has been known that neutrophils regularly appear within megakaryocytes (MKs), a histological phenomenon termed emperipolesis. Using new tools we developed to study this process in vitro and in vivo, we found that emperipolesis is common and increases with experimental inflammatory stress in a murine system. Neutrophils penetrate into the MK cytoplasm, donating a fraction of their surface membrane to platelets before emerging viable and intact. Our preliminary data show that neutrophils take up MK-derived exosomes during emperipolesis and emerge with enhanced migratory capacity. Building on these results, we explore the hypothesis that emperipolesis is a novel cell-in-cell interaction that modulates the function of neutrophils. We test this hypothesis in two independent but complementary aims. In Aim I, we examine the effect of emperipolesis, and in particular of MK exosomes, on neutrophil effector functions, metabolism, and in vivo migration in neutrophil-dependent K/BxN serum transfer arthritis. In Aim II, we employ whole-mount 3D marrow imaging, 2-photon in vivo microscopy, and specific MK deletion and potentially emperipolesis blockade to test the possibility that emperipolesis represents a quantitatively important pathway of neutrophil egress from bone marrow in vivo, including in experimental arthritis. Together, these studies will define a new form of cooperation between MKs and neutrophils that modulates the ability of neutrophils to participate in health and disease. More generally, building upon our recent identification of MKs as a source of IL-1 in arthritis, these studies continue to develop the understanding of MKs and neutrophils as participants in systemic inflammatory disease. These “high risk, high reward” studies of a previously overlooked biological process, widely conserved across mammalian species, will set the stage for an extended investigation of emperipolesis as a novel cell-in-cell phenomenon.