UPR determinants of Brucella virulence

布鲁氏菌毒力的 UPR 决定因素

基本信息

批准号：
10218621
负责人：
Judith Anne Smith
金额：
$ 23.33万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-19 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10218621
关键词：
ATF6 gene Address Affect Animals Apoptosis Apoptotic Arthritis Bacteria Bacterial Infections Brucella Brucella abortus Brucella melitensis Brucella suis Brucellosis Cells Cellular Stress Clinical Complication Development Disease Disease model Endocarditis Endoplasmic Reticulum Gene Expression Genes Human Immune response Induced Abortion Infection Inflammation Inflammatory Inflammatory Response Ingestion Inhalation Invaded Iris Joints Lead Link Mediating Mediator of activation protein Modeling Mouse Strains Mus Myalgia Orchitis Pathogenesis Pathogenicity Penetrance Peripheral Phagocytes Process Production Proteins RIII Mouse Refractory Reporting Role Side Signal Transduction Spondylarthritis Stress Structure Symptoms Testing Tissue-Specific Gene Expression Toll-like receptors Treatment Failure Up-Regulation Vaccines Vacuole Virulence Virulence Factors Virulent Work ZAP-70 Gene Zoonoses abortion arm biological adaptation to stress coping cost cytokine economic cost economic impact endoplasmic reticulum stress flu human disease human morbidity in vivo interleukin-23 macrophage mouse model mutant pathogen protein activation response species difference transcription factor transcription factor CHOP

项目摘要

PROJECT SUMMARY Brucellosis remains the most prevalent zoonosis worldwide, incurring significant human morbidity and economic impact. No safe human vaccine exists. The species most often implicated in human disease, B. melitensis has proven refractory to eradication. Following ingestion or inhalation, Brucella invade macrophages and other phagocytes, and traffic within vacuoles to the endoplasmic reticulum (ER) where they establish a replicative niche. During this process, Brucella induce a host stress response known as the “Unfolded Protein Response” (UPR). The UPR enables cells to cope with ER stress by transiently decreasing protein production and expanding ER capacity. However, if ER stress is prolonged or profound, the UPR initiates apoptosis. We have noted a striking correlation between extent of UPR induction and human virulence. In contrast to B. abortus and the vaccine strain S19, B. melitensis (the most virulent species) induces marked upregulation of the UPR target gene C/EBP homologous protein (CHOP) in murine and human macrophages. In certain bacterial infections, CHOP enhances virulence. CHOP critically contributed to apoptosis and abortion in a Brucella murine model. CHOP also stimulates the production of pro-inflammatory cytokines (e.g. IL-23) that could lead to human disease manifestations such as spondyloarthritis. Currently, the role of CHOP in Brucella infection of macrophages and spondyloarthritis is unknown, and there are no appropriate disease models to address this specific question. We hypothesize that the induction of a more extensive UPR by B. melitensis contributes to the virulence and pathogenicity of this species. To gain a greater understanding of the critical interactions between Brucella, host UPR and the development of arthritis, we propose the following aims: Aim 1: Test the hypothesis that CHOP contributes to the virulence of B. melitensis via greater bacterial replication and induction of specific host inflammatory responses. We will confirm our preliminary findings of species-specific UPR induction and expand upon these results by comparing macrophage gene expression induced by B. melitensis vs. B. abortus. Further, ddit3 (CHOP)-/- macrophages will delineate the portion of differential gene expression due to CHOP. We will determine if CHOP regulates apoptosis, replication or cell-cell spread of B. melitensis. Finally, the requirement for CHOP in B. melitensis replication and host inflammatory responses will be determined in vivo. Aim 2: Establish a mouse model of Brucella spondyloarthritis using spondyloarthritis-susceptible mice. Within recent years, several murine spondyloarthritis models have been developed that require either cytokine or infectious triggers, namely the SKG-ZAP-70 mutant model and B10.RIII mice. We will systematically test these mice strains to establish a robust, tractable model of Brucella-induced spondyloarthritis that will enable testing of our overarching hypothesis. An increasing number of pathogens have been recognized to manipulate the UPR. This work will contribute to the understanding of how the UPR mediates the relationships between bacterial invaders, host responses and disease manifestations.

项目概要布鲁氏菌病仍然是世界范围内最流行的人畜共患病，造成严重的人类发病率和经济损失不存在安全的人类疫苗，而最常与人类疾病有关的物种是羊种伯氏杆菌。经证明难以根除，摄入或吸入后，布鲁氏菌会侵入巨噬细胞和其他细胞。吞噬细胞，并在液泡内运输至内质网 (ER)，在那里它们建立复制在此过程中，布鲁氏菌诱导宿主应激反应，称为“未折叠蛋白质反应”。 (UPR) 使细胞能够通过暂时减少蛋白质产生和扩增来应对 ER 应激。然而，如果 ER 应激持续或严重，UPR 就会引发细胞凋亡。与流产布鲁氏菌和 B. abortus 相比，UPR 诱导程度与人类毒力之间存在显着相关性。疫苗株 S19，B. melitensis（毒性最强的物种）诱导 UPR 靶标显着上调小鼠和人类巨噬细胞中的基因 C/EBP 同源蛋白 (CHOP) 在某些细菌感染中， CHOP 增强布鲁氏菌小鼠模型的毒力。 CHOP 还会刺激促炎细胞因子（例如 IL-23）的产生，从而导致人类疾病目前，CHOP在巨噬细胞和布鲁氏菌感染中的作用。脊柱关节炎尚不清楚，并且没有合适的疾病模型来解决这个具体问题。研究表明，羊种芽孢杆菌诱导更广泛的 UPR 有助于增强毒力和为了更好地了解该物种的致病性，布鲁氏菌与宿主之间的关键相互作用。 UPR 和关节炎的发展，我们提出以下目标：目标 1：检验 CHOP 的假设通过更大的细菌复制和诱导特定的细菌，有助于提高 B. melitensis 的毒力我们将确认物种特异性 UPR 诱导和的初步发现。通过比较羊种芽孢杆菌和流产芽孢杆菌诱导的巨噬细胞基因表达来扩展这些结果。此外，ddit3 (CHOP)-/- 巨噬细胞将描绘由于 CHOP 导致的差异基因表达的部分。我们将确定 CHOP 是否调节羊种芽孢杆菌的细胞凋亡、复制或细胞间传播。羊种布鲁氏菌复制和宿主炎症反应对 CHOP 的需求将在体内确定。目标2：利用脊柱关节炎易感小鼠建立布鲁氏菌脊柱关节炎小鼠模型。近年来，已经开发了几种需要细胞因子的小鼠脊柱关节炎模型或传染性触发因素，即 SKG-ZAP-70 突变模型和 B10.RIII 小鼠，我们将系统地测试这些。小鼠菌株建立了布鲁氏菌引起的脊柱关节炎的稳健、易处理模型，该模型将能够进行测试越来越多的病原体被认为可以操纵我们的总体假设。这项工作将有助于了解 UPR 如何介导细菌之间的关系。入侵者、宿主反应和疾病表现。