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.

项目摘要/摘要 脓毒症仍然与20%到30%的高死亡率有关，每年的成本为240亿美元。 占美国所有住院总费用的近五分之一。流行性脓毒症 管理层表示支持。因此，确定治疗方法是一项紧迫的任务，以改善 败血症的结局。中性粒细胞作为先天免疫细胞的第一道防线消灭微生物。在脓毒症中， 夸大的从头产生的中性粒细胞称为紧急粒细胞生成，主要通过G-CSF发生 制作。然而，未成熟的中性粒细胞也被释放到循环中，以满足对 中性粒细胞数量较多，但其抗菌防御功能较差，导致脓毒症患者宿主防御能力较差 病人。G-CSF本身不会触发中性粒细胞的完全成熟。因此，通过干预来实现 促进中性粒细胞成熟是脓毒症中更好的宿主防御的关键。整合素CD11c为 被认为是区分脓毒症和全身炎症反应综合征的敏感标记物。我们 以往研究表明，CD11c KO小鼠在盲肠诱导的多菌败血症中存活率较低 结扎和穿孔(CLP)手术，表明CD11c在脓毒症中的关键作用。已经有很少的 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)及其缺陷与BM中性粒细胞减少有关 成熟。在总结紧急粒细胞生成的小鼠模型中，成熟的中性粒细胞在 CD11c KO小鼠与野生型(WT)小鼠相比数量显著减少，进一步表明其 中性粒细胞成熟的重要性。我们创造了CD11c结构性活性敲入(KI)小鼠，它 在稳定状态和感染期间，骨髓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 CRISPR/Cas9技术显示原代小鼠CD11c KO中性粒细胞或HL-60细胞缺乏CD11c 中性粒细胞成熟较少。基于这些结果，我们假设CD11c的活性将显著 调节中性粒细胞在稳定状态下的成熟程度和细胞内的紧急粒细胞生成 举止。我们的初步数据表明，CD11c也将调节中性粒细胞效应的一个子集。 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 效应器功能稳定，目标1和目标2败血症。因为IQGAP1被认为是一个 作为CD11c的结合伙伴，其作用也将被研究，以阐明CD11c如何调节的机制 中性粒细胞成熟和效应功能。研究将通过使用人类脓毒症受试者和小鼠进行 模特们。由于目前尚无CD11c小分子激动剂和拮抗剂，我们将对其进行筛选。 在目标3.在提案完成后，我们预计我们将巩固CD11c将是一个关键 中性粒细胞成熟调节因子和效应器功能用于脓毒症的治疗干预。