The impact of mucociliary clearance on Mycobacterium tuberculosis pathogenesis

粘液纤毛清除对结核分枝杆菌发病机制的影响

• 批准号: 10666055
• 负责人: Javeed Ali Shah
• 金额: $ 25.65万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-21 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10666055
• 关键词: Adverse effects; Alveolar; Alveolar Macrophages; Animal Model; Bacterial Infections; Bacterial Pneumonia; Biology; Cause of Death; Characteristics; Clinical; Complement; Complex; Data; Development; Disease; Disease model; Disease susceptibility; Dissection; Environment; Functional disorder; Future; Gene Expression; Genetic; Genetic Polymorphism; Genetic Variation; Genetic study; Goals; Grant; Growth; Homeostasis; Host Defense; Human; Human Genetics; IL17 gene; Immune; Immune response; Impairment; Individual; Infection; Inflammation; Inflammatory Response; Innate Immune Response; Integration Host Factors; Interleukin-13; Investigation; Knock-out; Knowledge; Lung; Lung diseases; MUC5AC gene; MUC5B gene; Macrophage; Maps; Measures; Meningeal Tuberculosis; Mucins; Mucociliary Clearance; Mucous Membrane; Mus; Mycobacterium tuberculosis; Organism; Outcome; Pathogenesis; Pathogenicity; Pathologic; Pathology; Persons; Phenotype; Play; Population; Predisposition; Promoter Regions; Proteins; Pulmonary Fibrosis; Pulmonary Pathology; Pulmonary Tuberculosis; Respiratory Mucin; Role; Sampling; Severities; Severity of illness; Shapes; Signal Transduction; Specificity; Structure of parenchyma of lung; Susceptibility Gene; Symptoms; TNF gene; Testing; Therapeutic; Tissues; Tuberculosis; Tuberculosis Vaccines; Vaccines; Variant; Vietnam; Vietnamese; Viral; Work; adaptive immune response; antimicrobial; antimicrobial peptide; biobank; cohort; cost; cytokine; extracellular; genetic variant; glycosylation; immune activation; improved; in vivo; innovation; interest; interleukin-23; lung pathogen; mRNA Expression; macromolecule; migration; mortality; mouse model; mucosal vaccination; multiple myeloma M Protein; mycobacterial; novel; novel vaccines; overexpression; pathogen; prevent; response; translational impact; transmission process; treatment strategy; tumor; tumor-immune system interactions; vaccine strategy

Project Summary/Abstract. Over one million people died from tuberculosis in 2021. Current treatments are long, costly, and often induce severe adverse effects, but the current vaccine has not been improved in over 100 years. Improved understanding of the host factors that influence Mtb pathogenesis in the lung may dramatically improve control and transmission of Mtb between individuals. Before entering the alveolar macrophage, Mtb encounters respiratory mucins. Mucins are glycosylated macromolecules that encompass the first line of defense against pathogens. Respiratory mucins MUC5B and MUC5AC protect the lung from pathogens via mucociliary clearance, directly inhibiting antimicrobial growth, and altering macrophage signaling. However, little is known about how these macromolecules influence Mtb susceptibility and severity. In this pilot grant, we will evaluate how respiratory mucins impact Mtb pathogenesis using human genetic studies, combined with interrogation of their mechanism of action via small animal models recapitulating Muc5b or Muc5ac insufficiency, deficiency, or overexpression. Our long-term goal is to identify strategies for effective Mtb killing within the lung and improve mucosal delivery of relevant candidate Mtb vaccines. The objective of this grant is to characterize the mechanisms by which MUC5B and MUC5AC, the two commonest respiratory mucins, influence Mtb susceptibility and severity in human populations. The rationale for this study is that respiratory mucins are essential for mucociliary clearance, support a host of extracellular antimicrobial peptides and proteins in the lung, and coats pathogens to alter their pathogenicity in the lung. Our preliminary data demonstrates that common genetic variants in the MUC5B promoter region are associated with pulmonary TB and MUC5B mRNA expression in the lung, while variation in the MUC5AC gene region is associated with TB meningitis mortality and MUC5AC mRNA expression. The central hypothesis is that MUC5B and MUC5AC are physical barriers to infection and also modulate macrophage function and systemic immune homeostasis to worsen TB disease severity. In this grant, we will test this hypothesis by achieving the following specific aims: 1) We will define the functional SNPs that regulate MUC5B and MUC5AC gene expression in the lung, systemic immune responses to TB meningitis, and susceptibility to and severity of TB in a Vietnamese cohort. 2) We will determine the mechanism by which Muc5b and Muc5ac deficiency, knockout, and overexpression influence clinical and immune responses to Mtb using genetically modified mice infected with Mtb. This contribution is significant because mucins represent the first line of defense against Mtb infection, but their role in Mtb pathogenesis is unknown. The proposed work is innovative because we will investigate the mechanisms and effects of a known TB susceptibility gene using innovative mouse models of disease, combined with the genetic cohorts of TB susceptibility. These studies will provide evidence that Mtb host defense begins prior to macrophage infection and provide clues toward the role of the immune microenvironment on Mtb outcomes.

项目摘要/摘要。2021年有100多万人死于结核病。目前的治疗方法是 时间长、费用高，而且往往会引起严重的不良反应，但目前的疫苗在100多年里一直没有改进 好几年了。对影响结核分枝杆菌肺部致病的宿主因素的了解可能会显著提高。 改善对结核分枝杆菌的控制和个人之间的传播。在进入肺泡巨噬细胞之前，结核分枝杆菌 会遇到呼吸道粘液。粘蛋白是围绕第一道防线的糖基化大分子。 对抗病原体。呼吸道粘蛋白MUC5B和MUC5AC通过粘液纤毛保护肺免受病原体侵袭 清除，直接抑制抗菌生长，并改变巨噬细胞信号。然而，人们对此知之甚少 关于这些大分子如何影响结核易感性和严重程度。在这笔试点拨款中，我们将评估 用人类遗传学研究结合询问呼吸道粘蛋白如何影响结核杆菌发病 它们的作用机制是通过小动物模型再现MUC5B或MUC5AC的不足、不足或 过度表达。我们的长期目标是确定有效杀死肺部结核杆菌的策略，并改善 相关候选结核分枝杆菌疫苗的粘膜递送。这笔赠款的目的是为了描述 最常见的两种呼吸道粘蛋白MUC5B和MUC5AC影响结核分枝杆菌的机制 人类群体中的易感性和严重性。这项研究的基本原理是呼吸道粘蛋白是 对粘液纤毛清除至关重要，支持肺内大量细胞外抗菌肽和蛋白质， 并包裹病原体以改变它们在肺部的致病性。我们的初步数据表明， MUC5B启动子区域的基因变异与肺结核和MUC5B基因相关 在肺中的表达，而MUC5AC基因区域的变异与结核脑膜炎死亡率相关 MUC5AC基因的表达。中心假说是MUC5B和MUC5AC是身体障碍 感染，还调节巨噬细胞功能和全身免疫稳态，使结核病恶化 严肃性。在这笔赠款中，我们将通过实现以下具体目标来检验这一假设：1)我们将定义 调节肺中MUC5B和MUC5AC基因表达的功能性SNPs，全身免疫反应 与结核病脑膜炎有关，以及越南队列中的结核病易感性和严重程度。2)我们将确定 MUC5B和MUC5ac缺乏、基因敲除和过表达影响临床和临床的机制 利用感染结核分枝杆菌的转基因小鼠对结核分枝杆菌的免疫应答。这一贡献是巨大的 因为粘蛋白是对抗结核分枝杆菌感染的第一道防线，但它们在结核杆菌致病中的作用是 未知。这项拟议的工作具有创新性，因为我们将研究已知的 利用结核病易感基因创新的小鼠疾病模型，结合结核病的遗传队列 敏感度。这些研究将提供证据，证明结核分枝杆菌宿主防御在巨噬细胞感染之前就开始了。 并为免疫微环境对结核分枝杆菌转归的作用提供线索。