Role of Rapid IFNg Secretion by CD*+ T cells in Clearance of Food Borne Listeria

CD* T 细胞快速分泌 IFNg 在清除食源性李斯特菌中的作用

• 批准号: 8343492
• 负责人: SARAH E. F. D'ORAZIO
• 金额: $ 36.23万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-20 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8343492
• 关键词: Address; Adoptive Transfer; Animal Model; Antigens; Bacteria; CD8-Positive T-Lymphocytes; CD8B1 gene; Cells; Cellular biology; Cheese; Colon; Dendritic Cells; Disease; Dose; Eating; Enterocytes; Feces; Food; Gastroenteritis; Gastrointestinal tract structure; Genes; Growth; Hepatocyte; Host resistance; Human; Immune; Immune response; Immunologist; In Vitro; Individual; Infection; Inflammatory; Ingestion; Interferons; Interleukin-12; Interleukin-18; Intestinal Mucosa; Intestines; Intravenous; Kinetics; Knowledge; Lamina Propria; Left; Life; Life Style; Listeria; Listeria monocytogenes; Listeriosis; Liver; Lymphocyte; M cell; Mammalian Cell; Meat; Memory; Meningoencephalitis; Modeling; Mus; Natural Immunity; Oral; Organism; Outcome; Pathway interactions; Patients; Peripheral; Phenotype; Population; Predisposition; Process; Proteins; Public Health; Research Personnel; Resistance; Role; Seeds; Sepsis; Septicemia; Severities; Signal Transduction; Small Intestines; Source; Spleen; Stomach; Symptoms; System; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Time; Tissues; adaptive immunity; cell mediated immune response; cell type; cytokine; feeding; foodborne; foodborne infection; human disease; in vivo; insight; killings; macrophage; mortality; oral infection; pathogen; receptor; response; tool; transmission process

DESCRIPTION (provided by applicant): Listeria monocytogenes (Lm) is important an important pathogen to study because: 1) it causes life threatening food borne infections of significant public health concern, 2) it is a genetically tractable organism with a unique intracellular lifestyle used as a tool for understanding the cell biology of mammalian cells, and 3 systemic (i.v.) listeriosis is a highly reproducible infection frequently used by immunologists to study cell- mediated immune responses. Due to the lack of a small animal model that closely mimics human disease, we still know very little about oral transmission of Lm, or why the innate susceptibility to developing severe gastroenteritis, sepsis, and meningoencephalitis varies among individuals. To address this knowledge gap, we recently developed a new model of oral listeriosis using mice fed Lm-contaminated food. This natural feeding model revealed clear differences in the ability of Lm to colonize the gut and spread systemically in susceptible (BALB) vs. resistant (B6) mice. Thus, for the first time, we can now study how gut-adapted Lm that survive digestive processes in the stomach are able to colonize the intestinal mucosa and serve as a nidus for continual seeding of peripheral tissues in susceptible mice unable to quickly clear the gut infection. Since the vast majority of patients hospitalized with listeriosis can be considered immune compromised in some way, it has long been thought that protective immune responses were critical for limiting the infection to a mild gastroenteritis in resistant individuas. Our central hypothesis predicts that one such innate immune mechanism is the rapid secretion of IFN¿ by a subset of memory phenotype CD8+ T cells. We postulate that T cell-derived IFN¿ can rapidly initiate clearance mechanisms in B6 mice and that the delay in activation of CD8+ T cells in BALB mice allows Lm to replicate exponentially and spread to systemic tissues. This application has three specific aims: (1) to identify the cell types in the colon that support Lm growth and thus, serve as the targets of protective innate immune responses; (2) to identify the specific subsets of CD8+ T cells that rapidly secrete IFN¿ after ingestion of Lm and show that this T cell-derived IFN¿ can rapidly limit the intracellular growth of Lm in the colon; (3) to idenify IFN¿-dependent innate immune mechanisms that promote rapid clearance of Lm in peripheral tissues after dissemination from the gut. A key strategy in this application will be the use of a unique adoptive transfer system wherein T cells from a responsive mouse are injected into a MHC-matched non-responsive mouse. This powerful approach will allow us to specifically isolate the function of IFN¿ rapidly produced by CD8+ T cells while leaving all other innate immune mechanisms intact. The expected outcomes of the proposed studies are: [1] significant new insights into the pathogenic life style of food borne Lm, and [2] a better understanding of the innate immune mechanisms that determine host resistance/susceptibility to intracellular bacterial pathogens. PUBLIC HEALTH RELEVANCE: Listeria monocytogenes (Lm) is transmitted by ingestion of contaminated "ready-to-eat" food products such as unpasteurized cheeses, deli meats, and produce. Human infections vary greatly in severity from a mild, self- limiting gastroenteritis to life-threatening septicemia and meningoencephalitis, and the host susceptibility factors that contribute to this range of disease are not defined. In this study, we test the idea that resistant individuals respond to infection by rapidly producing a protective protein that activates multiple killing mechanisms that quickly clear the bacteria while susceptible individuals lack the ability t orchestrate this rapid immune response.

描述（由适用提供）：单核细胞增生李斯特菌（LM）是重要的重要病原体，因为：1）它会导致生命威胁性的食物传播感染的重要公共卫生问题，2）它是一种通用的可触觉的生物体，它具有独特的细胞内生活方式，用于理解乳细胞和3个Systemicic（i.v. i.v.）的细胞生物学，并用作独特的细胞内生活方式（i.v.）。免疫学家研究细胞介导的免疫反应。由于缺乏紧密模仿人类疾病的小动物模型，我们仍然对LM口服传播知之甚少，或者为什么对患者患上严重的胃炎，败血症和脑膜脑炎的先天敏感性在个体中有所不同。为了解决这一知识差距，我们最近使用饲喂LM污染的食物的小鼠开发了一种新的口服李斯特氏病模型。这种自然的喂养模型揭示了LM在肠道上定居并在易感性（BALB）与抗性（B6）小鼠中系统地扩散的能力明显差异。这是我们现在第一次可以研究肠道适应的LM如何在摊位中生存的消化过程能够定植肠粘膜，并用作易感小鼠外周组织连续播种的Nidus，无法快速清除肠胃感染。由于绝大多数患有李斯特氏病住院的患者可以被认为是以某种方式损害的，因此长期以来一直认为，受保护的免疫反应对于将感染限制为耐药个体中的轻度胃肠炎至关重要。我们的中心假设预测，这种先天免疫机制是通过记忆表型CD8+ T细胞的子集对IFN的快速分泌。我们假设T细胞衍生的IFN可以快速启动B6小鼠的清除机制，并且BALB小鼠中CD8+ T细胞激活的延迟允许LM允许LM复制指数并扩散到全身组织。该应用具有三个特定的目的：（1）识别结肠中支持LM生长的细胞类型，从而充当受保护的先天免疫反应的靶标； （2）确定在摄入LM后快速分泌IFN的CD8+ T细胞的特定子集，并表明该T细胞衍生的IFN可以迅速限制结肠中LM的细胞内生长； （3）鉴于依赖性的先天免疫机制，这些机制促进了从肠道传播后在外围时间快速清除LM。本应用程序中的关键策略将是使用独特的自适应转移系统，其中将来自响应鼠标的T细胞注入了MHC匹配的无反应小鼠中。这种强大的方法将使我们能够特别隔离CD8+ T细胞迅速产生的IFN的功能，同时使所有其他先天的免疫力学完整。拟议的研究的预期结果是：[1]对传播的LM的致病生活方式的重要新见解，[2]更好地理解了决定宿主对细胞内细菌病原体的宿主抵抗/易感性的先天免疫力学。 公共卫生相关性：单核细胞增生李斯特菌（LM）是通过摄入受污染的“即食”食品（如未经巴氏消毒的奶酪，熟食肉和农产品）来传播的。人类感染的严重程度差异很大，从轻度，自限制的胃炎到威胁生命的败血病和脑膜脑炎，以及造成这种疾病范围的宿主易感因素。在这项研究中，我们测试了抗性的想法 个体通过迅速产生一种受保护的蛋白质来应对感染的反应，该蛋白会激活多种杀伤机制，这些杀伤机制迅速清除细菌，而易感人则缺乏协调这种快速免疫反应的能力。