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，特别是对美国军事人员而言 经常被部署到结核病高发地区的人，结核分枝杆菌 (Mtb) 是一种呼吸道疾病。 病原体通过吸入传染性空气颗粒传播。大多数感染者会产生保护作用。 免疫力有助于遏制有机体，但大约 10% 最终会发展为活动性结核病。 分枝杆菌特异性 CD4+ T 细胞在肺部的定位似乎对于预防分枝杆菌感染至关重要 Mtb 感染，目前使用皮内 (ID) 牛分枝杆菌 BCG 进行结核病疫苗接种可能无法得到优化。 使用支气管肺泡灌洗 (BAL) 获得的肺细胞进行的研究提供了一种评估局部免疫的方法 对结核分枝杆菌的反应可能与评估新型结核病疫苗具有独特的相关性。 最近的小鼠研究进一步强调了肺内的免疫力，表明呼吸道 感染后会出现位于肺实质的 CD4+ 记忆 T 细胞 并且不会重新加入全身循环。这些组织驻留记忆 T 细胞 (TRM) 表现出独特的特征。 表型，并且还显示出增强的预防 Mtb 呼吸道感染的能力。 静脉内 (IV) 注射泛白细胞抗体，以识别不与 T 细胞通讯的 T 细胞 脉管系统提供了一种从血管相关记忆细胞中分选肺 TRM 的方法。 尚未应用一种有趣的方法来阐明基于 BAL 的免疫研究的重要性 然而，这一步对于将这些见解最终应用到人类研究中至关重要。 当前提案的总体目标是阐明 BAL 中 CD4+ T 细胞的机制 与其他肺 CD4+ T 细胞群不同，并且与其他肺 CD4+ T 细胞群相互作用，介导淋巴细胞募集 我们的研究团队是独一无二的。 有资格解决这些问题，因为它包括具有基于支气管镜检查的研究经验的研究人员 人类对 Mtb 免疫的评估（Richard Silver，PI），小鼠对 Mtb 免疫的评估（W. Henry Boom， 顾问）和涉及小鼠和人类肺细胞的免疫测定的优化（Tracey Bonfield，联合研究员）。我们也将从应用先驱的参与中受益匪浅。 研究 Mtb 感染的 TRM 方法（NIAID 的 Daniel Barber，顾问）我们的研究将采用一种方法。 Mtb 感染的小鼠模型，其中通过 IV 注射染色的肺匀浆细胞（“IV+ T 细胞”）相关 与肺血管系统相关的T细胞是从不能以这种方式标记的“IV-T细胞”中分选出来的。 主要显示 TRM 表型并保留在实质内，我们将应用这种方法。 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 在小鼠中进行的平行人类研究将利用基线 BAL 细胞和通过建模获得的独特样本。 使用纯化蛋白进行支气管镜分段抗原激发，回忆对 Mtb 蛋白抗原的反应 Mtb (PPD) 的衍生物将被整合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 与 IV- 和 IV+ 肺匀浆 CD4+ T 细胞群不同； 2) 确定 BAL CD4+ T 细胞与 IV- 和 IV+ CD4+ 肺 T 细胞相互作用的机制 向肺实质和气道招募额外的 T 细胞； 3) 确定BAL和肺实质CD4+ T细胞相互作用介导的机制 预防有毒力结核分枝杆菌的呼吸道感染。