Parenchymal and airway CD4+ T cells in protection against pulmonary tuberculosis

实质和气道 CD4 T 细胞预防肺结核

• 批准号: 10291777
• 负责人: RICHARD F SILVER
• 金额: --
• 依托单位: LOUIS STOKES CLEVELAND VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10291777
• 关键词: Address; Adoptive Cell Transfers; Adoptive Transfer; Animal Model; Antibodies; Antigens; Area; Barbering; Blood Circulation; Blood Vessels; Bronchoalveolar Lavage; Bronchoscopy; CD4 Positive T Lymphocytes; CXCR3 gene; Cells; Child Development; Communication; Complex; Containment; Development; Evaluation; Exposure to; Genus Mycobacterium; Goals; Health; Homing; Human; Immune; Immune response; Immunity; Immunology procedure; Individual; Infection; Inhalation; Injections; Interferon Type II; International; Intravenous; Label; Laboratories; Leukocytes; Ligands; Lung; Lymphocyte; Mediating; Memory; Methodology; Military Personnel; Modeling; Modification; Mus; Mycobacterium Infections; Mycobacterium bovis; Mycobacterium tuberculosis; National Institute of Allergy and Infectious Disease; Nature; Organism; Phenotype; Population; Prevalence; Proteins; Public Health; Pulmonary Tuberculosis; Research; Research Personnel; Respiratory Tract Infections; Risk; Sampling; Silver; Site; Stains; Structure of parenchyma of lung; Surface; T memory cell; T-Lymphocyte; Tail; Tissues; Tuberculosis; Tuberculosis Vaccines; Vaccination; Vaccines; Veins; Veterans; Virulent; Work; antigen challenge; base; chemokine; experience; insight; intravenous injection; memory CD4 T lymphocyte; mouse model; novel; novel strategies; particle; prevent; recruit; respiratory; respiratory pathogen; response; study population; tuberculin purified protein derivative; vaccination against tuberculosis; vaccine-induced immunity

Tuberculosis (TB) remains a significant international public health threat, particularly for US military personnel who are often deployed to areas of high TB prevalence. Mycobacterium tuberculosis (Mtb) is a respiratory pathogen spread via inhalation of infectious airborne particles. Most infected individuals develop protective immunity that serves to contain the organism, but approximately 10% will eventually develop active TB. The localization of mycobacteria-specific CD4+ T cells to the lung appears to be critical to protection against Mtb infection, and may not be optimized by current TB vaccination with intradermal (ID) M. bovis BCG. Human studies using lung cells obtainable by bronchoalveolar lavage (BAL) provide a means to assess local immune responses to Mtb that may be uniquely relevant to evaluating novel TB vaccines. The distinct nature of local immunity within the lung has been further emphasized by recent murine studies demonstrating that respiratory infection is followed by the development of CD4+ memory T cells that are localized to the lung parenchyma and do not rejoin the general circulation. These tissue-resident memory T cells (TRM) display a distinct phenotype, and also show increased capacity to protect against respiratory infection with Mtb. The use of intravenous (IV) injection of pan-leukocyte antibodies to identify T cells that are not in communication with the vasculature has provided a means to sort pulmonary TRM from vascular-associated memory cells. This intriguing approach has not yet been applied to clarifying the significance of BAL-based studies of immunity to Mtb; this step is critical, however, to the ultimate application of these insights to human studies. The overall goal of the current proposal is to clarify the mechanisms by which CD4+ T cells within BAL differ from and interact with other lung CD4+ T-cell populations to mediate lymphocyte recruitment to the lung and, ultimately, protection against respiratory challenge with Mtb. Our research team is uniquely qualified to address these issues, as it includes investigators with experience in bronchoscopy-based studies of human immunity to Mtb (Richard Silver, PI), murine assessments of immunity to Mtb (W. Henry Boom, Consultant) and optimization of immune assays involving lung cells from both mice and humans (Tracey Bonfield, Co-investigator). We will also greatly benefit from the involvement of a pioneer in the application of TRM methodology to the study of Mtb infection (Daniel Barber of NIAID, Consultant). Our studies will utilize a murine model of Mtb infection in which lung homogenate cells stained by IV injection (“IV+ T cells”) associated with the lung vasculature are sorted from T cells that cannot be labeled in this manner. These “IV- T cells” predominantly display a TRM phenotype and are retained within the parenchyma. We will apply this approach to evaluate the interactions of IV- and IV+ lung CD4+ T cells and to clarify their relationship to BAL CD4+ T cells in mice. Parallel human studies will utilize both baseline BAL cells and unique samples obtained by modeling recall responses to Mtb protein antigens using bronchoscopic segmental antigen challenge with purified protein derivative of Mtb (PPD). These approaches will be integrated to address the following Specific Aims: 1) To determine the mechanisms by which mycobacteria-specific CD4+ T cells in BAL are phenotypically distinct from IV- and IV+ lung homogenate CD4+ T-cell populations; 2) To determine the mechanisms by which BAL CD4+ T-cells interact with IV- and IV+ CD4+ lung T-cell populations to recruit additional T cells to the lung parenchyma and airways; 3) To determine the mechanisms by which BAL and lung parenchymal CD4+ T cells interact to mediate protection against respiratory infection with virulent M. tuberculosis.

结核病（TB）仍然是一个重大的国际公共卫生威胁，特别是对于美国军事人员 他们经常被部署到高结核病患病率的地区。结核分枝杆菌（MTB）是呼吸道 病原体通过吸入传染性空气传播颗粒传播。大多数受感染的人受到保护 用于包含生物体的免疫力，但大约10％的免疫力最终会发展为活跃的结核病。 分枝杆菌特异性的CD4+ T细胞在肺部的定位似乎对于保护至关重要 MTB感染，可能不会通过用皮内（ID）M。Bovis BCG来优化TB疫苗接种。人类 使用支气管肺泡灌洗可获得的肺细胞（BAL）的研究提供了一种评估局部免疫的方法 对MTB的反应可能与评估新型TB疫苗有关。当地的独特本质 最近的鼠研究表明，呼吸道的肺部的免疫力进一步强调了 感染之后是局部局部肺实质的CD4+记忆T细胞的发展 并且不要重新加入一般循环。这些组织驻留的记忆T细胞（TRM）显示出独特的 表型，并且还显示出可预防MTB呼吸道感染的能力。使用 静脉注射（IV）注射泛白细胞抗体，以鉴定与不与之通信的T细胞 脉管系统提供了一种从血管相关记忆细胞中分类肺TRM的方法。这 尚未应用有趣的方法来阐明基于BAL的免疫研究对 MTB;但是，此步骤对于这些见解在人类研究中的最终应用至关重要。 当前建议的总体目标是阐明BAL内CD4+ T细胞的机制 与其他肺CD4+ T细胞群体不同，并与淋巴细胞募集到 肺部，最终可以保护MTB的呼吸挑战。我们的研究团队是独特的 有资格解决这些问题，因为它包括具有支气管镜研究经验的研究人员 对MTB的人类免疫学（Richard Silver，PI），对MTB免疫的鼠评估（W. Henry Boom， 顾问）和对涉及小鼠和人类肺细胞的免疫测定的优化（特蕾西 Bonfield，共同投资者）。我们还将大大受益于一名先驱者的应用 MTB感染研究的TRM方法论（Niaid的Daniel Barber，顾问）。我们的研究将利用 MTB感染的鼠模型，其中IV注射（“ IV+ T细胞”）相关的肺匀浆细胞染色 用肺脉管系统从无法以这种方式标记的T细胞中分类。这些“ iv- T细胞” 主要显示TRM表型，并保留在副群中。我们将把这种方法应用于 评估IV-和IV+肺CD4+ T细胞的相互作用，并阐明它们与BAL CD4+ T细胞的关系 在老鼠中。平行的人类研究将同时利用基线BAL细胞和通过建模获得的独特样品 使用纯化蛋白质的支气管镜节段抗原挑战对MTB蛋白抗原的回忆反应 MTB（PPD）的导数。这些方法将集成以解决以下特定目的： 1）确定BAL中分枝杆菌特异性CD4+ T细胞的机制是表型 不同于IV-和IV+肺匀浆CD4+ T细胞种群； 2）确定BAL CD4+ T细胞与IV-和IV+ CD4+肺T细胞相互作用的机制 种群将其他T细胞招募到肺实质和气道； 3）确定BAL和肺实质CD4+ T细胞相互作用以介导的机制 防止毒性结核分枝杆菌的呼吸道感染。