Determinants of human neutrophil fate after phagocytosis

吞噬作用后人类中性粒细胞命运的决定因素

• 批准号: 10092904
• 负责人: William M. Nauseef
• 金额: $ 48.68万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10092904
• 关键词: Apoptosis; Apoptotic; Cell Death; Cells; Cessation of life; Complex; Cytoplasmic Granules; Disease; Environment; Failure; Generations; Health; Homeostasis; Host Defense; Human; Infection; Inflammasome; Inflammation; Inflammatory; Inflammatory Response; Ingestion; Innate Immune Response; Interleukin-1 beta; Invaded; Membrane; Microbe; Mission; NADPH Oxidase; Necrosis; Neisseria gonorrhoeae; Oxidants; Pathway interactions; Phagocytes; Phagocytosis; Phagosomes; Phase; Phosphotransferases; Production; Proliferating Cell Nuclear Antigen; Protein Kinase; Proteins; RIPK1 gene; Resolution; Role; Serine Protease; Signal Pathway; Signal Transduction; Staphylococcus aureus; System; Time; Tissues; cytokine; first responder; human pathogen; insight; macrophage; microbicide; neutrophil; novel; receptor; tool

Human innate immune response to microbes depends on the coordinated interactions among a variety of cells and secreted factors, with polymorphonuclear leukocytes (PMN) typically prominent among the first responders. In their capacity as phagocytic cells, PMN sequester ingested prey in membrane-bound phagosomes, where oxidants from the NADPH oxidase and proteins from granules synergize to create a toxic environment that promotes death and degradation of the engulfed microbe. In certain settings, a significant fraction of ingested microbes survives within PMN. The persistence of viable microbes within phagosomes not only provides a mechanism for sustained infection but also can modulate the local inflammatory tone by altering the programmed cell death of PMN and promoting PMN release of proinflammatory cytokines. Interference with phagocytosis-induced apoptosis of PMN (PICD), either by delaying apoptosis, as seen with N. gonorrhoeae (Ngc) or engaging a novel necrotic cell death pathway, as seen with Staphylococcus aureus (SA), thwarts resolution of the inflammatory response and causes release of host-derived danger signals that promote inflammation and secondary tissue damage. Thus, effective innate immune response requires not only death and degradation of invading microbes but also resolution of inflammation and reestablishment of homeostasis. The overarching hypothesis of this proposal is that the failure of PMN to undergo apoptotic cell death derails the resolution phase of the inflammatory response and instead amplifies disease. Because activated human PMN (hPMN) and their secreted products can sculpt the inflammatory tone in tissue, we propose to use Ngc and SA -- both human pathogens that survive within PMN, alter phagocytosis- induced cell fate pathways and elicit profound inflammatory local changes – as tools to probe mechanisms that dictate phagocyte fate and timely resolution of inflammation. We will pursue two Specific Aims: Aim 1: To determine the mechanisms that regulate human PMN fate . A. Determine the signaling pathways that differentially direct hPMN towards survival vs programmed cell death (apoptosis vs primary necrosis). B. Determine the composition and activities of the ripoptosome (intracellular complexes) in hPMN after phagocytosis C. Determine the role of Proliferating Cell Nuclear Antigen (PCNA) in the fate of phagocytosing hPMN Aim 2: To determine the mechanisms underlying hPMN secretion of IL-1β during phagocytosis A. Identify the role of inflammasomes in IL-1β production by hPMN during phagocytosis B. Determine the importance of serine proteases in generation of IL-1β C. Determine the role of Receptor-interacting kinase-3 (RIPK-3) in hPMN IL-1β secretion

人类对微生物的先天免疫反应取决于多种微生物之间的协调相互作用 细胞和分泌因子，其中多形核白细胞 (PMN) 通常是最重要的 响应者。作为吞噬细胞，PMN 将摄取的猎物隔离在膜结合的状态中 吞噬体，NADPH 氧化酶中的氧化剂和颗粒中的蛋白质协同作用，产生有毒物质 促进被吞噬微生物死亡和降解的环境。在某些设置下，显着 摄入的微生物的一部分在 PMN 中存活。吞噬体内活微生物的持久性不 不仅提供了持续感染的机制，还可以通过调节局部炎症张力 改变 PMN 的程序性细胞死亡并促进 PMN 释放促炎细胞因子。 通过延迟细胞凋亡来干扰吞噬作用诱导的 PMN 细胞凋亡 (PICD)，如 淋病奈瑟菌 (Ngc) 或参与一种新的坏死细胞死亡途径，如金黄色葡萄球菌所示 (SA)，阻碍炎症反应的解决并导致宿主衍生的危险信号的释放 促进炎症和继发性组织损伤。因此，有效的先天免疫反应不需要 不仅是入侵微生物的死亡和降解，而且还包括炎症的消退和免疫系统的重建。 体内平衡。该提案的总体假设是 PMN 未能经历细胞凋亡 细胞死亡破坏了炎症反应的消退阶段，反而加剧了疾病。 因为激活的人类中性粒细胞 (hPMN) 及其分泌产物可以塑造体内的炎症基调 组织，我们建议使用 Ngc 和 SA——这两种人类病原体都在 PMN 中生存，改变吞噬作用—— 诱导细胞命运途径并引发深刻的炎症局部变化——作为探索机制的工具 决定吞噬细胞的命运和炎症的及时解决。我们将追求两个具体目标： 目标 1：确定调节人类 PMN 命运的机制 。 A. 确定分别指导 hPMN 生存与编程的信号通路 细胞死亡（细胞凋亡与原发性坏死）。 B. 确定 hPMN 中核糖体（细胞内复合物）的组成和活性 吞噬作用 C. 确定增殖细胞核抗原 (PCNA) 在吞噬 hPMN 命运中的作用 目标 2：确定吞噬过程中 hPMN 分泌 IL-1β 的机制 A. 确定炎症小体在吞噬过程中 hPMN 产生 IL-1β 中的作用 B. 确定丝氨酸蛋白酶在 IL-1β 生成中的重要性 C. 确定受体相互作用激酶 3 (RIPK-3) 在 hPMN IL-1β 分泌中的作用