Dissecting the molecular regulation of T cell localization and function within the Mycobacterium tuberculosis granuloma

剖析结核分枝杆菌肉芽肿内 T 细胞定位和功能的分子调控

基本信息

批准号：
10550190
负责人：
Benjamin Henry Gern
金额：
$ 18.65万
依托单位：
SEATTLE CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-13 至 2026-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10550190
关键词：
Ablation Address Affect Antibiotic Therapy Antibiotics Antigens Autopsy Award BCG Live BLR1 gene Biological Assay CCR CCR6 gene CD4 Positive T Lymphocytes CXCR3 gene Career Mobility Cells Cellular Immunity Cessation of life Clinical Development Development Plans Diffuse Disease Outcome Dose Exhibits Flow Cytometry Future Genetic Genetic Transcription Goals Granuloma Homing Human Image Imaging Device Immune Immune response Immunity Immunization Immunology Immunosuppression In Situ Individual Infection Infiltration Investigation Knock-out Knockout Mice Knowledge Laboratories Learning Lung Lung infections Lymphocyte Macrophage Macrophage Activation Manuscripts Microbe Microscopy Modeling Molecular Mus Mycobacterium tuberculosis Outcome Pathogenesis Pathway interactions Patients Physicians Physiological Play Research Resources Role Scientist Shapes Signal Transduction Site Structure of parenchyma of lung T cell regulation T-Cell Activation T-Lymphocyte Techniques Testing Tissues Training Transforming Growth Factor beta Tuberculosis Vaccination Vaccine Design advanced analytics career career development cell type chemokine receptor conditional knockout effector T cell experimental study global health improved in vivo innovation lung pathogen mouse model novel novel therapeutics novel vaccines pulmonary granuloma receptor response single cell analysis tertiary lymphoid organ trafficking transcriptomics treatment strategy tuberculosis granuloma tuberculosis immunity tuberculosis treatment

项目摘要

PROJECT SUMMARY/ABSTRACT Mycobacterium tuberculosis (Mtb) infection is a major global health problem. Despite widespread immunization with Bacillus Calmette–Guérin and availability of antibiotic therapy, there are 10 million new cases and 1.4 million deaths annually, underscoring the need for improved treatment strategies. CD4 T cell-mediated immunity is critical for protection against Mtb infection, and is governed by 1) appropriate trafficking of CD4 T cells to distinct compartments within the Mtb-infected lung, including sites of infection, and 2) robust effector function at these sites. We have uncovered a spatially-resolved immunosuppressive mechanism by which localized TGFβ signal plays a dominant role in limiting the presence and function of T effector cells within the granuloma, with the greatest effect directly adjacent to infected cells. We have shown that ablation of T cell TGFβR-signaling reverses this suppression and results in reduced bacterial burdens. Here we propose to dissect the mechanistic underpinnings of these observations and address the central hypothesis that: Inappropriate localization of CD4 T cells, in combination with pleiotropic inhibition by localized TGFβ activation within the granuloma core limits effective immunity to Mtb pulmonary infection. To address this hypothesis, we will use a tractable yet physiologic murine ultra-low dose model of Mtb infection and advanced analytical microscopy, then confirm concepts learned in mice in human pulmonary granulomas as follows: 1) We will comprehensively characterize how individual chemokine receptors contribute to CD4 T cell localization, activation, function and ultimately, infection outcome. These findings will be corroborated in human granulomas. 2) We will also characterize how TGFβ activation by individual cell types limits localized CD4 T cell activation, function and infection outcome. This will be validated in granulomas from patients who die from active TB and those with asymptomatic Mtb infection who die from other causes, an unparalleled resource in the antibiotic era. These studies will also yield information about additional inhibitory pathways that are present within pulmonary granuloma and provide a framework for their characterization which can be pursued in future R01 applications. Thus, this proposal will leverage the strengths of our ULD Mtb mouse model and innovative imaging tools to understand how T cells traffic to infected sites and characterize a dominant immunosuppressive factor within this space, which has important implications for vaccine design and host-directed therapy. Dr. Gern’s career development plan builds on a background of using advanced imaging to study pulmonary pathogens with coursework and hands-on training in advanced immunology, Mtb pathogenesis, advanced microscopy, and laboratory management. A K08 award will allow Dr. Gern to make maximal use of SCRI and UW’s extensive scientific resources to achieve scientific independence, advancing his career goal to understand the factors dictating immune cell trafficking and function within different tissue microenvironments during Mtb infection, with the ultimate goal of improving tuberculosis treatment.

项目概要/摘要尽管免疫接种已广泛开展，但结核分枝杆菌 (Mtb) 感染仍是一个主要的全球健康问题。随着卡介苗和抗生素治疗的可用性，有 1000 万新病例和 140 万例每年都有人死亡，这凸显了改进 CD4 T 细胞介导的免疫治疗策略的必要性。对于预防 Mtb 感染至关重要，并受以下因素控制：1) 将 CD4 T 细胞适当运输到不同的区域 Mtb 感染的肺内的隔室，包括感染部位，以及 2) 这些区域的强大效应器功能我们发现了一种空间分辨的免疫抑制机制，通过该机制定位 TGFβ 信号。在限制肉芽肿内 T 效应细胞的存在和功能方面起主导作用，我们已经证明，T 细胞 TGFβR 信号传导的消融可逆转。这种抑制并导致细菌负担减少。在这里，我们建议剖析其机制。这些观察结果的基础并解决了以下中心假设： CD4 的不适当定位 T 细胞，结合肉芽肿核心范围内局部 TGFβ 激活的多效性抑制为了解决这一假设，我们将使用一种易于处理且符合生理学的方法。 Mtb 感染的小鼠超低剂量模型和先进的分析显微镜，然后确认学到的概念在人类肺肉芽肿中的小鼠中，如下：1）我们将全面描述个体如何趋化因子受体有助于 CD4 T 细胞的定位、激活、功能以及最终的感染结果。这些发现将在人类肉芽肿中得到证实 2) 我们还将描述 TGFβ 的激活方式。个别细胞类型限制局部 CD4 T 细胞的激活、功能和感染结果，这一点将得到验证。死于活动性结核病的患者和死于无症状结核分枝杆菌的患者的肉芽肿中其他原因，抗生素时代无与伦比的资源，这些研究也将产生有关的信息。肺肉芽肿中存在的其他抑制途径并为其提供了框架因此，该提案将利用这些优势。我们的 ULD Mtb 小鼠模型和创新成像工具可了解 T 细胞如何运输到感染部位并描述了该领域的主要免疫抑制因素，这对疫苗设计和宿主导向治疗。格恩博士的职业发展计划建立在使用背景的基础上。高级成像研究肺部病原体，并提供高级课程和实践培训免疫学、结核分枝杆菌发病机制、先进显微镜学和实验室管理将授予 Dr. Gern 最大限度地利用 SCRI 和威斯康星大学广泛的科学资源来实现科学独立，推进他的职业目标，以了解决定不同免疫细胞运输和功能的因素结核分枝杆菌感染期间的组织微环境，最终目标是改善结核病治疗。