A. actinomycetemcomitans Cdt induces pro-inflammatory innate immune responses

A. actinomycetemcomitans Cdt 诱导促炎先天免疫反应

基本信息

批准号：
8640913
负责人：
BRUCE J SHENKER
金额：
$ 40万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8640913
关键词：
1-Phosphatidylinositol 3-Kinase Actinobacillus actinomycetemcomitans Agonist Antigens Apoptosis Bacteria Binding Carrier Proteins Cell Cycle Arrest Cell Degranulation Cell Line Cells Dinoprostone Disease Exhibits Future GLUT4 gene Generations Glucose Glycogen Synthase Kinase 3 Goals Health Host Defense Human Immune response Immune system Immunologics Immunosuppressive Agents Immunotoxins Infection prevention Inflammation Mediators Inflammatory Inflammatory Response Inflammatory Response Pathway Interleukin-1 Interleukin-13 Interleukin-6 Intervention Intracellular Membranes Investigation Lead Leukotriene B4 Leukotrienes Lipids Lymphocyte Mediating Mediator of activation protein Metabolic Natural Immunity Operon Organism PTEN gene Pathogenesis Pathway interactions Periodontal Diseases Phosphatidylinositols Phosphoric Monoester Hydrolases Play Predisposition Production Proliferating Prostaglandins Proteins Role Signal Pathway Signal Transduction T-Lymphocyte TLR2 gene TNF gene Testing Toxic effect Toxin Tumor Suppressor Proteins Vesicle Virulence adaptive immunity cellugyrin cytokine cytolethal distending toxin glucose uptake holotoxins human PHEMX protein in vivo macrophage mast cell meetings microorganism mutant novel oral pathogen pathogen research study response trafficking tripolyphosphate

项目摘要

DESCRIPTION (provided by applicant): The immune system, by and large, plays a primary role to minimize and/or prevent infection, in general, and periodontal disease, in particular. We propose that perturbation of both innate and adaptive immune responses contribute to the pathogenesis of and susceptibility to periodontal disease. The fundamental hypothesis of our studies is that periodontal pathogens produce immunomodulatory proteins that alter either innate or adaptive immunity, thereby enhancing their own virulence and/or that of other opportunistic microorganisms. Our investigations have demonstrated that Aggregatibacter actinomycetemcomitans produces an immunotoxin, the cytolethal distending toxin (Cdt), that impairs human T-cells by inducing cell cycle arrest and apoptosis. In this proposal we focus on a novel, nonlethal, effect of Cdt on two critical cells that comprise the innate immune system. Specifically, we propose the Cdt induces a pro-inflammatory response by virtue of its ability to act as a PIP3 phosphatase, deplete cells of this critical signaling lipid and in turn block PI-3K signaling leading to decreased pAkt to activation of GSK3¿. Preliminary studies indicate that treatment of the human macrophage cell line, THP1, and human macrophages with Cdt results in the synthesis and release of pro-inflammatory cytokines (TNF¿ and IL-1¿) as well as enhancement of TLR agonist-induced cytokine release. Cdt also augments de novo synthesis of cytokines (IL-6 and IL-13) following mast cell activation. These effects on both macrophages and mast cells are consistent with PIP3 depletion, blockade of the PI-3K signaling pathway and the role of this pathway as a negative regulator of the pro-inflammatory response. We now plan to extend these preliminary studies to define the extent and mechanism by which Cdt alters the synthesis and release of inflammatory mediators by human macrophages and mast cells. The study is divided into three specific aims: (1) To define the pro-inflammatory effects of Cdt on the innate immune response of macrophages and mast cells; ( 2) To determine if the Cdt-mediated pro-inflammatory effects on the innate immune system ais dependent upon PIP3 phosphatase activity and altered PI-3K/PIP3/Akt signaling; and (3) To determine the role of cellugyrin and, possibly GSK3¿, in Cdt-mediated altered glucose uptake and utilization and its relationship to the pro-inflammatory response. It is anticipated that these studies will lead to a more detailed understanding of Cdt mode of action and contribute to a greater understanding of the pathogenesis of disease caused by Cdt-producing bacteria. In addition to advancing our understanding of Cdt mode of action, these studies will advance our understanding of the mechanism(s) by which the PI-3K signaling pathway regulates TLR-mediated cytokine production. Thus these studies will identify new targets for future in vivo studies involving pharmacologic and immunologic intervention in disease caused by bacteria that produce Cdt.

描述（由适用提供）：总体而言，免疫系统尤其是最小化和/或防止感染的主要作用，尤其是牙周疾病。我们建议，先天和适应性免疫响应的扰动有助于对牙周疾病的发病机理和易感性。我们研究的基本假设是牙周病原体产生的免疫调节蛋白会改变先天或适应性免疫，从而增强其自己的病毒和/或其他机会性微生物的病毒。我们的研究表明，聚集的放线菌ctemcetemans会产生一种免疫毒素，即细胞骨化的毒素（CDT），从而通过诱导的细胞周期停滞和细胞凋亡损害了人类T细胞。在此提案中，我们着重于CDT对两个构成先天免疫系统的两个关键细胞的新颖，非致命的影响。具体而言，我们提出CDT通过其充当PIP3磷酸酶的能力，该临界信号传导脂质的完全不同的细胞促进了促炎反应，并且会阻止PI-3K信号传导，从而导致PAKT降低到GSK3的激活。初步研究表明，用CDT治疗人类巨噬细胞系，THP1和人类巨噬细胞会导致促炎性细胞因子（TNFC和IL-1？）的合成和释放，并增强TLR激动剂诱导的细胞因子释放。 CDT还增加了肥大细胞激活后细胞因子（IL-6和IL-13）的从头合成。这些对巨噬细胞和肥大细胞的影响与PIP3耗竭，PI-3K信号通路的阻断以及该途径作为促炎反应的负调节剂的作用一致。现在，我们计划扩展这些初步研究，以定义CDT改变人类巨噬细胞和肥大细胞炎症介质的合成和释放的程度和机制。该研究分为三个具体目的：（1）定义CDT对巨噬细胞和肥大细胞的先天免疫反应；（2）确定CDT介导的对先天免疫系统AIS的促炎作用是否取决于PIP3磷酸酶活性并改变了PI-3K/PIP3/AKT信号传导；（3）确定Clyugyrin和可能的GSK3缺的作用，在CDT介导的改变的葡萄糖摄取和利用改变及其与促炎反应的关系。可以预料，这些研究将导致对CDT作用方式的更详细的了解，并有助于对产生CDT的细菌引起的疾病的发病机理有更多了解。除了促进我们对CDT作用方式的理解外，这些研究还将提高我们对PI-3K信号通路调节TLR介导的细胞因子产生的机制的理解。这些研究将确定未来在体内研究的新目标，这些研究涉及由产生CDT的细菌引起的药物和免疫学干预措施。