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: 10723106
• 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 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10723106
• 关键词: Address; Adoptive Cell Transfers; Adoptive Transfer; Animal Model; Antibodies; Antigens; Area; Barbering; Blood Vessels; Bronchoalveolar Lavage; Bronchoscopy; CD4 Positive T Lymphocytes; CXCR3 gene; Cell Communication; Cells; Child Development; Circulation; 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; Intravenous Immunoglobulins; 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; Persons; Phenotype; Population; Prevalence; Proteins; Public Health; Pulmonary Tuberculosis; Qualifying; Research; Research Personnel; Respiratory Tract Infections; Risk; Sampling; Silver; Site; Sorting; 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; chemokine; experience; insight; intravenous injection; memory CD4 T lymphocyte; mouse model; novel; novel strategies; particle; prevent; recruit; respiratory; respiratory challenge; respiratory pathogen; response; study population; tissue resident memory T cell; 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，特别是对美国军事人员 他们经常被部署到结核病高发区。结核分枝杆菌(Mtb)是一种呼吸道疾病 病原体通过吸入具有感染性的空气微粒而传播。大多数感染者会产生保护性 一种免疫力，可以遏制这种微生物，但大约10%的人最终会发展成活动性结核病。 分枝杆菌特异性的CD4+T细胞在肺中的定位似乎是预防肺炎的关键。 结核分枝杆菌感染，并且可能不会通过目前的皮内接种牛分枝杆菌卡介苗来优化。人类 使用通过支气管肺泡灌洗(BAL)获得的肺细胞的研究提供了一种评估局部免疫的手段 对结核分枝杆菌的反应可能与评估新的结核病疫苗唯一相关。地方性的独特性质 最近的小鼠研究进一步强调了肺内的免疫，表明呼吸道 感染之后是定位于肺实质的CD4+记忆T细胞的发展 并且不要重新加入一般的循环。这些组织驻留的记忆T细胞(TRM)表现出明显的 表型，并显示出增强的能力，以防止呼吸道感染结核分枝杆菌。对.的使用 静脉(IV)注射泛白细胞抗体，以识别与T细胞没有联系的T细胞 血管系统提供了一种从血管相关记忆细胞中分离肺TRM的方法。这 耐人寻味的方法尚未被用来澄清基于BAL的免疫研究的意义 然而，这一步对于将这些见解最终应用于人类研究是至关重要的。 目前提案的总体目标是澄清BAL内CD4+T细胞的机制 与肺内其他CD4+T细胞群不同并相互作用，以介导淋巴细胞募集 Mtb对肺部和最终对呼吸挑战的保护作用。我们的研究团队独一无二 有资格解决这些问题，因为它包括在支气管镜检查方面有经验的调查人员 人类对结核分枝杆菌免疫的评估(Richard Silver，Pi)，小鼠对结核分枝杆菌免疫的评估(W.Henry Boom， 顾问)以及涉及小鼠和人类肺细胞的免疫分析的优化(Tracey 邦菲尔德，联合调查员)。我们还将极大地受益于一家先驱参与应用 研究结核分枝杆菌感染的TRM方法(NIAID的Daniel Barber，顾问)。我们的研究将利用 小鼠肺组织匀浆细胞静脉注射(“IV+T细胞”)染色的结核分枝杆菌感染模型 从不能以这种方式标记的T细胞中分离出具有肺血管的T细胞。这些“IV-T细胞” 主要表现为TRM表型，并保留在实质内。我们将把这种方法应用于 评价IV-和IV+肺CD4+T细胞的相互作用及其与BAL CD4+T细胞的关系 在老鼠身上。平行的人体研究将利用基线BAL细胞和通过建模获得的独特样本 支气管镜下节段性抗原用纯化蛋白激发对结核分枝杆菌蛋白抗原的召回反应 Mtb的衍生物(Ppd)。这些方法将结合起来，以实现以下具体目标： 1)确定BAL中分枝杆菌特异性CD4+T细胞表型的机制 有别于IV-和IV+肺匀浆中的CD4+T细胞群； 2)探讨BAL CD4+T细胞与IV-和IV+CD4+肺T细胞相互作用的机制 向肺实质和呼吸道招募额外T细胞的人群； 3)探讨BAL与肺实质CD4+T细胞相互作用的机制 预防强毒结核分枝杆菌呼吸道感染。