Autophagy proteins in the immune response to Mycobacterium tuberculosis infection

自噬蛋白在结核分枝杆菌感染免疫反应中的作用

基本信息

批准号：
10054156
负责人：
Christina Leigh Stallings
金额：
$ 48.04万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-11-07 至 2023-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10054156
关键词：
Affect Alveolar Macrophages Antigen Presentation Antigen-Presenting Cells Apoptosis Apoptotic Autophagocytosis Biological Assay Cell Survival Cells Cessation of life Data Defect Dendritic Cells Disease Outcome Dissection Host Defense Human ITGAX gene Immune Immune response Immunotherapy In Vitro Infection Infection Control Infectious Agent Inflammation Inflammatory Interferon Type II Lead Lung Monitor Mouse Strains Mus Mycobacterium tuberculosis Myeloid Cells Natural Immunity Pathogenesis Pathology Pathway interactions Phagocytosis Phenotype Play Population Predisposition Production Proteins Reporting Role S100A8 gene Signal Transduction T-Lymphocyte Testing Tuberculosis adaptive immune response adaptive immunity base chemokine cytokine effective therapy effector T cell expectation experimental study in vitro Assay in vivo insight interest macrophage monocyte neutrophil recruit response trafficking transcriptome sequencing

项目摘要

PROJECT SUMMARY/ABSTRACT Mycobacterium tuberculosis (Mtb) infection kills more people a year than any other single infectious agent. Both the disease outcome and the pathology of TB are driven by the immune response mounted in the host, which is dictated by interactions between cells involved in innate and adaptive immunity. Because of the pivotal role of the immune response in TB, there is a growing interest in developing immunotherapies that harness the immune response to control the infection. In particular, there is interest in stimulating autophagy to control Mtb infection. The role of autophagy in controlling Mtb infection was based on the observation that Atg5fl/fl-LysM-cre mice lacking Atg5 in monocyte-derived cells and neutrophils (polymorphonuclear cells, PMN) succumb to Mtb within 30 days, an extremely severe phenotype similar to mice lacking IFN-γ signaling. Atg5 is an essential autophagy protein and the dogma in the field was that Atg5 was required in macrophages to target Mtb for lysosomal degradation through macroautophagy. Contrary to expectation, we have demonstrated that Atg5 is required in myeloid cells to control Mtb infection due to an autophagy-independent function that regulates PMN-dominated inflammation. In addition, using mice that conditionally delete Atg5 only in PMN (Atg5fl/fl- MRP8-cre), we have shown that loss of Atg5 in PMNs can result in susceptibility to Mtb infection, revealing a PMN intrinsic role for Atg5 during Mtb infection. Therefore, it will be important to better understand the roles for autophagy proteins in host defense to understand the scope of effects that may occur while intervening with autophagic flux with host-directed therapies. Our dissection of Mtb pathogenesis in Atg5fl/fl-LysM-cre mice has revealed multiple stages where Atg5 functions in myeloid cells during infection. During Mtb infection, an early- infected Atg5-/- cell overproduces cytokines and chemokines that bring PMN into the lungs of Atg5fl/fl-LysM-cre mice in higher numbers than in control mice. The responding Atg5-/- PMN amplify the pro-inflammatory signals and a subset of Atg5-/- PMN are not cleared from the lung, which we predict occurs due to a defect in PMN apoptosis and/or efferocytosis of the apoptotic PMN. Efferocytosis of apoptotic Mtb-infected PMN is important for efficient antigen presentation. Indeed, the defect in clearing Atg5-/- PMN correlates with delayed trafficking of T cells to the lungs. Based on these preliminary data, I hypothesize that Atg5 plays roles in multiple myeloid cells during Mtb infection, including an autophagy-independent function in PMN, and together these functions of Atg5 lead to control of Mtb pathogenesis. To test this hypothesis, I will determine the mechanistic basis for how loss of Atg5 in myeloid cells leads to PMN accumulation and precludes a protective adaptive immune response to Mtb by pursuing the following aims: 1) Dissect the roles for Atg5 in regulating production of pro- inflammatory signals during infection, 2) Define the roles for Atg5 in regulating PMN accumulation and clearance during Mtb infection, 3) Determine how loss of Atg5 in myeloid cells affects adaptive immune responses to Mtb.

项目概要/摘要结核分枝杆菌 (Mtb) 感染每年造成的死亡人数比任何其他单一传染源都要多。结核病的疾病结果和病理是由宿主体内的免疫反应驱动的，这是由于参与先天免疫和适应性免疫的细胞之间的相互作用所决定。结核病的免疫反应，人们对开发利用免疫反应的免疫疗法越来越感兴趣特别是，人们对刺激自噬来控制结核分枝杆菌感染感兴趣。自噬在控制 Mtb 感染中的作用是基于 Atg5fl/fl-LysM-cre 小鼠的观察单核细胞来源的细胞和中性粒细胞（多形核细胞，PMN）中缺乏 Atg5，会死于 Mtb 30天后，出现与缺乏Atg5信号的小鼠类似的极其严重的表型。自噬蛋白和该领域的教条是巨噬细胞需要 Atg5 来靶向 Mtb 与预期相反，我们已经证明 Atg5 是通过巨自噬进行溶酶体降解的。由于自噬独立的调节功能，骨髓细胞需要控制结核分枝杆菌感染此外，使用仅在 PMN 中条件性删除 Atg5 的小鼠（Atg5fl/fl-）。 MRP8-cre），我们已经证明 PMN 中 Atg5 的缺失会导致对 Mtb 感染的易感性，揭示了 PMN 在 Mtb 感染过程中的内在作用因此，更好地了解 Atg5 的作用非常重要。宿主防御中的自噬蛋白，以了解干预时可能发生的影响范围我们对 Atg5fl/fl-LysM-cre 小鼠 Mtb 发病机制的剖析揭示了在 Mtb 感染过程中 Atg5 在骨髓细胞中发挥作用的多个阶段。受感染的 Atg5-/- 细胞过量产生细胞因子和趋化因子，将 PMN 引入 Atg5fl/fl-LysM-cre 的肺部与对照小鼠相比，反应性 Atg5-/- PMN 放大了促炎信号。 Atg5-/- PMN 的一个子集没有从肺部清除，我们预测这是由于 PMN 缺陷而发生的凋亡性 Mtb 感染的 PMN 的细胞凋亡和/或胞吞作用很重要。事实上，清除 Atg5-/- PMN 的缺陷与延迟运输相关。根据这些初步数据，我发现 Atg5 在多发性骨髓细胞中发挥作用。 Mtb 感染期间的细胞，包括 PMN 中的自噬独立功能，以及这些功能的结合 Atg5 导致 Mtb 发病机制的控制为了验证这一假设，我将确定其机制基础。骨髓细胞中 Atg5 的缺失如何导致 PMN 积聚并阻碍保护性适应性免疫系统通过追求以下目标来应对 Mtb： 1) 剖析 Atg5 在调节 pro-生产中的作用感染期间的炎症信号，2) 定义 Atg5 在调节 PMN 积累和清除中的作用在 Mtb 感染期间，3) 确定骨髓细胞中 Atg5 的缺失如何影响 Mtb 的适应性免疫反应。