CD11c as a novel target to improve neutrophil effector functions and sepsis outcome

CD11c 作为改善中性粒细胞效应功能和脓毒症结局的新靶点

• 批准号: 10552923
• 负责人: Koichi Yuki
• 金额: $ 38.94万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10552923
• 关键词: Accounting; Adult; Advocate; Aging; Agonist; Binding; Biological Assay; Biological Markers; Blood; Bone Marrow; CD34 gene; CRISPR/Cas technology; Cell Adhesion Molecules; Cell surface; Cells; Child; Circulation; Clinical Trials; Complement Receptor; Data; Dendritic Cells; Development; Emergency Situation; Escherichia coli; Future; Generations; Genes; Genetic Transcription; Goals; Granulocyte Colony-Stimulating Factor; Granulopoiesis; HL-60 Cells; Hematopoietic stem cells; Heterogeneity; Hospital Mortality; Hospitalization; Host Defense; Human; ITGAX gene; ITGB2 gene; Immune; In Vitro; Incidence; Infection; Integrin Binding; Integrins; Intervention; Knock-in Mouse; Knockout Mice; Leukocytes; Ligand Binding; Ligands; Microbe; Modeling; Morbidity - disease rate; Mus; Ontology; Operative Surgical Procedures; Outcome; Output; Patients; Phagocytes; Play; Population; Production; Proliferating; Reporting; Research; Role; Sampling; Sepsis; Signal Pathway; Sterility; Supportive care; Systemic Inflammatory Response Syndrome; Testing; Therapeutic; Therapeutic Intervention; Time; Translations; United States; Wild Type Mouse; aged; antagonist; antimicrobial; candidate identification; cecal ligation puncture; cost; cytokine; experimental study; improved; improved outcome; in vivo; member; microbial; mortality; mouse model; neutrophil; novel; novel therapeutics; peripheral blood; polymicrobial sepsis; precursor cell; septic; septic patients; single-cell RNA sequencing; small molecule; transcriptomic profiling

Project Summary/ Abstract Sepsis remains to be associated with a high mortality of 20 to 30% with annual cost of $24 billion, accounting for nearly one-fifth of the total aggregate costs in all the hospitalizations in the United States. Current sepsis management is supportive. Therefore, identifying therapeutic approaches is an urgent task to improve the outcome of sepsis. Neutrophils eradicate microbes as the first-line defense innate immune cells. In sepsis, exaggerated de novo neutrophil production called emergency granulopoiesis occurs mainly via G-CSF production. However, immature neutrophils are also released into a circulation to meet a high demand for neutrophil number, but they have less antimicrobial defense functions, leading to worse host defense in septic patients. G-CSF itself does not trigger full neutrophil maturation. Thus, an intervention to attain the enhancement of neutrophil maturation is critical in sepsis for better host defense. Integrin CD11c was considered a sensitive marker to differentiate sepsis from systemic inflammatory response syndrome. We previously showed that CD11c KO mice had worse survival in the polymicrobial sepsis induced by cecal ligation and puncture (CLP) surgery, indicating the critical role of CD11c in sepsis. There has been a paucity of research about its functional role in vivo. We unexpectedly identified that CD11c was expressed in the bone marrow (BM) neutrophils (largely intracellular) and its deficiency was associated with less BM neutrophil maturation. In a mouse model to recapitulate emergency granulopoiesis, mature neutrophils were released in significantly less quantity in CD11c KO mice compared to wild type (WT) mice, further suggesting its importance in neutrophil maturation. We created CD11c constitutively active knock-in (KI) mice, which demonstrated to have more mature neutrophils in the BM in a steady-state condition and during infection with better bacterial eradication and outcomes. In addition, our in vitro neutrophil maturation experiments using primary murine CD11c KO neutrophils or HL-60 cells devoid of CD11c by CRISPR/Cas9 technology showed less neutrophil maturation. Based on these results, we hypothesized that CD11c activity would significantly regulate the degree of neutrophil maturation in a steady state and emergency granulopoiesis in a cell-intrinsic manner. Our preliminary data suggested that CD11c would also regulate a subset of neutrophil effector functions irrelevant of maturation. Thus, we will determine the role of CD11c in neutrophil maturation and effector functions in a steady state and sepsis in Aim 1 and Aim 2. Because IQGAP1 was suggested to be a binding partner for CD11c, its role will also be studied to delineate the mechanism of how CD11c regulates neutrophil maturation and effector functions. Studies will be done by using human sepsis subjects and murine models. Because there are no CD11c small molecule agonists and antagonists available, we will screen them in Aim 3. Upon the completion of the proposal, we expect that we would solidify that CD11c would be a critical regulator of neutrophil maturation and effector functions for a therapeutic intervention in sepsis.

项目概要/摘要 脓毒症仍然与 20% 至 30% 的高死亡率相关，每年造成 240 亿美元的损失， 占美国所有住院总费用的近五分之一。当前败血症 管理层是支持的。因此，寻找治疗方法是改善病情的紧迫任务。 败血症的结果。中性粒细胞作为第一道防御先天免疫细胞消灭微生物。在败血症中， 被称为紧急粒细胞生成的过度从头产生的中性粒细胞主要通过 G-CSF 发生 生产。然而，未成熟的中性粒细胞也被释放到循环中以满足对细胞的高需求。 中性粒细胞数量较多，但抗菌防御功能较少，导致脓毒症宿主防御能力较差 患者。 G-CSF 本身不会触发中性粒细胞完全成熟。因此，干预是为了实现 增强中性粒细胞成熟对于脓毒症中更好的宿主防御至关重要。整合素 CD11c 是 被认为是区分脓毒症和全身炎症反应综合征的敏感标志物。我们 先前表明，CD11c KO 小鼠在盲肠引起的多种微生物败血症中的存活率较差 结扎穿刺 (CLP) 手术，表明 CD11c 在脓毒症中的关键作用。已经有少量 研究其在体内的功能作用。我们意外地发现CD11c在骨骼中表达 骨髓 (BM) 中性粒细胞（主要在细胞内）及其缺乏与 BM 中性粒细胞减少有关 成熟。在重现紧急粒细胞生成的小鼠模型中，成熟的中性粒细胞被释放 与野生型（WT）小鼠相比，CD11c KO 小鼠的数量显着减少，进一步表明其 对中性粒细胞成熟的重要性。我们创建了 CD11c 组成型活性敲入 (KI) 小鼠， 证明在稳态条件下和感染期间，BM 中有更多成熟的中性粒细胞 更好的细菌根除和结果。此外，我们的体外中性粒细胞成熟实验使用 通过 CRISPR/Cas9 技术显示原代小鼠 CD11c KO 中性粒细胞或缺乏 CD11c 的 HL-60 细胞 中性粒细胞成熟较少。基于这些结果，我们假设 CD11c 活性会显着 调节稳态中的中性粒细胞成熟程度和细胞固有的紧急粒细胞生成 方式。我们的初步数据表明 CD11c 还会调节中性粒细胞效应子的一个子集 与成熟无关的功能。因此，我们将确定 CD11c 在中性粒细胞成熟和 效应器在目标 1 和目标 2 中处于稳态和脓毒症功能。因为 IQGAP1 被认为是 CD11c 的结合伴侣，我们还将研究其作用，以描述 CD11c 调节的机制 中性粒细胞成熟和效应功能。研究将使用人类脓毒症受试者和小鼠进行 模型。由于目前尚无可用的CD11c小分子激动剂和拮抗剂，我们将对其进行筛选 目标 3。提案完成后，我们预计我们将巩固 CD11c 将是一个关键的 中性粒细胞成熟和效应器功能的调节剂，用于脓毒症的治疗干预。