Macrophage defense againt M. tuberculosis

巨噬细胞对结核分枝杆菌的防御

• 批准号: 6725294
• 负责人: Jennifer P Wang
• 金额: $ 11.31万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6725294
• 关键词: CpG islands; Mycobacterium tuberculosis; alveolar macrophages; bioassay; biological signal transduction; cell cell interaction; cell line; cellular immunity; clinical research; confocal scanning microscopy; enzyme linked immunosorbent assay; flow cytometry; human subject; immunotherapy; microarray technology; nucleic acid sequence; pathologic process; phagocytosis; polymerase chain reaction; receptor expression; terminal nick end labeling; tissue /cell culture; toll like receptor

DESCRIPTION (provided by applicant): Tuberculosis is a leading cause of death from infection worldwide. Investigations of interactions between Mycobacterium tuberculosis (Mtb) and human macrophages are fundamental for understanding tuberculosis pathogenesis. Immunostimulatory DNA sequences and their synthetic oligonucleotide analogs (CpG-ODN) have been shown to exert antibacterial effects in vitro and in vivo, and we discovered that CpG-ODN activate anti-mycobacterial activity in human monoeyte-derived macrophages (hMDM). The goals of this K08 project are to more fully characterize the mechanism(s) and magnitude of this CpG-ODN effect. Experiments will determine whether anti-mycobacterial responses are activated thorugh TLR9, the only receptor known to be activated by CpG-ODN. While murine macrophages can be activated by interferon (IFN)-gamma to kill intracellular mycobacteria in vitro, we and others have found that IFN-gamma, paradoxically potentiates intracellular growth of the pathogen. The mechanisms whereby human macrophages restrict Mtb remain uncertain, and new knowledge may be gained through delineating the mechanisms acitvated by CpG-ODN. We will determine if this response is broadly applicable to different Mtb strains, and if there are differences between the activity of hMDM and human alveolar macrophages (the initial host cell infected by Mtb in vivo). We will also test whether macrophage-like cell lines (THP-1) can be used to model the CpG-ODN response, since these cells would facilitate molecular studies of Toll-dependent signaling. Clues to the mechanism of this CpG-ODN effect will be sought in functional studies ofmacrophage activation and signaling, and using microarrays to interrogate the transcriptome of stimulated cells broadly. Finally, we will compare the effects of stimulation through different Toll receptors with a panel of ligands to look for similarities or differences compared with CpG-ODN, and to identify potential synergies. These studies will provide new basic knowledge of the innate anti-mycobacterial functions of human macrophages, and they will provide a rational basis for the discovery of new immunotherapeutic strategies for tuberculosis.

描述（由申请人提供）：结核病是全世界感染死亡的主要原因。研究结核分枝杆菌 (Mtb) 和人类巨噬细胞之间的相互作用对于了解结核病发病机制至关重要。免疫刺激性 DNA 序列及其合成寡核苷酸类似物 (CpG-ODN) 已被证明在体外和体内发挥抗菌作用，我们发现 CpG-ODN 可以激活人单核细胞来源的巨噬细胞 (hMDM) 的抗分枝杆菌活性。该 K08 项目的目标是更全面地表征这种 CpG-ODN 效应的机制和程度。实验将确定抗分枝杆菌反应是否通过 TLR9 激活，TLR9 是已知的唯一被 CpG-ODN 激活的受体。虽然小鼠巨噬细胞可以被干扰素 (IFN)-γ 激活以在体外杀死细胞内分枝杆菌，但我们和其他人发现 IFN-γ 相反地增强了病原体的细胞内生长。人类巨噬细胞限制 Mtb 的机制仍不确定，通过描述 CpG-ODN 激活的机制可能会获得新的知识。我们将确定这种反应是否广泛适用于不同的 Mtb 菌株，以及 hMDM 和人肺泡巨噬细胞（体内 Mtb 感染的初始宿主细胞）的活性是否存在差异。我们还将测试巨噬细胞样细胞系 (THP-1) 是否可用于模拟 CpG-ODN 反应，因为这些细胞将促进 Toll 依赖性信号传导的分子研究。这种 CpG-ODN 效应机制的线索将在巨噬细胞激活和信号传导的功能研究中寻找，并使用微阵列广泛询问受刺激细胞的转录组。最后，我们将比较不同 Toll 受体与一组配体的刺激效果，以寻找与 CpG-ODN 相比的相似点或差异，并确定潜在的协同作用。这些研究将为人类巨噬细胞固有的抗分枝杆菌功能提供新的基础知识，并为发现新的结核病免疫治疗策略提供合理基础。