Impact of Mycobacterium tuberculosis on monocyte differentiation in vivo

结核分枝杆菌对体内单核细胞分化的影响

• 批准号: 10606380
• 负责人: Alexander Mohapatra
• 金额: $ 8.09万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 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 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10606380
• 关键词: 2019-nCoV; Adoptive Transfer; Affect; Alveolar Macrophages; Antimycobacterial Agents; Aspergillus; Attenuated; BCG Live; Bioinformatics; Bone Marrow; COVID-19; COVID-19 pandemic; Cause of Death; Cell Differentiation process; Cells; Chronic; Chronic Phase; Containment; Cryptococcus; Data; Dendritic Cells; Development; Drug resistance; Effectiveness; Environment; Flow Cytometry; Gene Expression; Gene Expression Profile; Generations; Genes; Genus Mycobacterium; Growth; Heterogeneity; Homeostasis; Human; Immune; Immune Evasion; Immune response; Infection; Infection Control; Inflammatory; Link; Lipopolysaccharides; Listeriosis; Lung; Lung infections; Monocytosis; Mononuclear; Multi-Drug Resistance; Mus; Mycobacterium bovis; Mycobacterium tuberculosis; Pathway interactions; Phagocytes; Pharmaceutical Preparations; Phase; Phenotype; Physicians; Population; Population Heterogeneity; Process; Production; Research; Research Personnel; Resources; Scientist; Signal Transduction; Site; Stimulus; Testing; Tissues; Toxoplasma; Training; Tuberculosis; Tuberculosis Vaccines; Vaccines; Virulence Factors; Work; adaptive immune response; chronic infection; experimental study; global health; granulocyte-monocyte progenitors; health disparity; improved; in vivo; innovation; insight; monocyte; mortality; mycobacterial; neutrophil; novel strategies; novel therapeutics; pathogen; permissiveness; progenitor; programs; recruit; resistant strain; response; single-cell RNA sequencing; stem cells

PROJECT SUMMARY Tuberculosis was the leading infectious cause of mortality worldwide from 2007 to 2019, only dethroned in 2020 by the Covid-19 pandemic. Unlike Covid-19, there is no effective vaccine for tuberculosis, so it will remain a leading infectious cause of death worldwide. With multidrug-resistant strains emerging, there is a critical need to develop new therapies that enhance the immune response to infection. The mechanisms used by Mtb to evade elimination are incompletely understood. The Ernst lab has observed that in mice infected with M. tuberculosis, certain phagocytes (mononuclear cell subset 1; MNC1) descended from bone marrow monocytes are especially “permissive”: they are more frequently infected than are other phagocytes and poorly eliminate engulfed mycobacteria. However, accumulation of monocyte-derived cells in inflamed tissues is associated with pathogen clearance in other infections. Recent work has also shown that the bone marrow monocyte population is not homogeneous; rather, subpopulations of monocytes have differing transcriptional profiles and have varying responses to distinct inflammatory stimuli. These data prompt the hypothesis that M. tuberculosis reprograms the bone marrow to produce monocytes that differentiate into lung cells that are highly permissive of mycobacterial growth and survival. To test this hypothesis, spectral flow cytometry will be used to determine whether acquisition of the phenotype observed in MNC1 cells begins in bone marrow monocytes from Mtb- infected mice. Bone marrow monocytes from uninfected and infected mice will also be co-transferred into infected recipients to determine whether monocyte origin influences differentiation into MNC1 cells. The heterogeneity of bone marrow monocytes will also be assessed by single-cell RNA sequencing to test multiple hypotheses about mechanisms underlying the differentiation of permissive lung cells. Monocytes from Mtb- infected mice will be compared to those from uninfected mice and from mice administered lipopolysaccharide. In a separate experiment, gene expression in bone marrow monocytes from Mtb-infected mice will be compared to that in monocytes from mice infected with the attenuated mycobacterial strain M. bovis bacillus Calmette- Guérin Pasteur, to link Mtb-specific genes to altered monocyte development. The proposed studies will improve understanding of how M. tuberculosis affects monocytes recruited to the lung from the bone marrow and could lead to host-directed therapies to augment their mycobactericidal activity, an innovative target that would increase the effectiveness of current anti-mycobacterial drugs. All work will be performed at UCSF, which offers a supportive, well-resourced training environment for physician-scientists like the applicant. The proposed studies will provide him with expertise in monocyte development, experimentation in a high-containment facility, and bioinformatic analysis, facilitating his transition to an independent investigator studying immune responses to lung infections.

项目概要 2007年至2019年，结核病是全球头号传染病，直到2020年才被取代 与 Covid-19 不同，结核病没有有效的疫苗，因此它仍将是一种结核病。 随着多重耐药菌株的出现，迫切需要解决这一问题。 开发增强对感染的免疫反应的新疗法 结核分枝杆菌逃避感染的机制。 恩斯特实验室观察到，在感染结核分枝杆菌的小鼠中，消除机制尚不完全清楚。 某些源自骨髓单核细胞的吞噬细胞（单核细胞亚群 1；MNC1）尤其具有 “宽容”：它们比其他吞噬细胞更容易被感染，并且被吞噬的清除效果较差 然而，单核细胞来源的细胞在发炎组织中的积累与病原体有关。 最近的研究还表明，骨髓单核细胞群并未被清除。 同质；相反，单核细胞亚群具有不同的转录谱并且具有不同的转录谱 这些数据提出了结核分枝杆菌重编程的假设。 骨髓产生单核细胞，这些单核细胞分化成高度允许的肺细胞 为了检验这一假设，将使用光谱流式细胞术来确定分枝杆菌的生长和存活。 MNC1 细胞中观察到的表型的获得是否始于 Mtb- 的骨髓单核细胞 未感染和感染小鼠的骨髓单核细胞也将被共同转移到体内。 感染的受体以确定单核细胞来源是否影响分化为 MNC1 细胞。 骨髓单核细胞的异质性也将通过单细胞RNA测序来评估，以测试多个 关于允许单核细胞从 Mtb- 分化的机制的假设。 将感染的小鼠与未感染的小鼠和施用脂多糖的小鼠进行比较。 在另一个实验中，将比较 Mtb 感染小鼠的骨髓单核细胞的基因表达 与来自感染减毒分枝杆菌菌株牛分枝杆菌卡介苗的小鼠的单核细胞中的结果相比， Guérin Pasteur，将 Mtb 特异性基因与改变的单核细胞发育联系起来。拟议的研究将改善。 了解结核分枝杆菌如何影响从骨髓募集到肺部的单核细胞，并且可以 导致宿主定向疗法以增强其杀分枝杆菌活性，这是一个创新目标 提高现有抗分枝杆菌药物的有效性所有工作将在 UCSF 进行，该机构提供 为像申请人这样的医师科学家提供一个支持性的、资源丰富的培训环境。 研究将为他提供单核细胞发育、高密闭设施实验方面的专业知识， 和生物信息分析，帮助他转变为研究免疫反应的独立研究者 肺部感染。