NEW ANIMAL MODEL FOR EHEC PATHOGENESIS AND PREVENTION

用于 EHEC 发病和预防的新动物模型

• 批准号: 6381972
• 负责人: JOAN R BUTTERTON
• 金额: $ 31.76万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-30 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6381972
• 关键词: Enterobacteriaceae; Enterobacteriaceae disease; Escherichia coli 0157:H7; Escherichia coli infections; Vibrio cholerae; attenuated microorganism; bacillary dysentery; bacterial antigens; bacterial vaccines; disease /disorder model; exotoxins; genetic transduction; hemolytic anemia; hemorrhagic disorders; laboratory mouse; live vaccine; lysogeny; mucosal immunity; nonhuman therapy evaluation; plasmids; renal failure; transfection /expression vector; vaccine development; vector vaccine

DESCRIPTION (adapted from the application) Investigation of the gastrointestinal disease and renal injury caused by enterohemorrhagic Escherichia coli (EHEC) and the development and testing of interventions to prevent disease following infection have been hampered by the lack of a convenient animal model that effectively reproduces the typical human colonic disease that progresses to HUS. The Principal Investigator proposes to develop the use of a new mouse model of EHEC infection with the long term goal of increasing the ability to study disease pathogenesis and prevention. The new animal model will be compared with prior models in the evaluation of vaccine strategies against EHEC. This will be accomplished through the following two Specific Aims: 1. Evaluation of the use of Citrobacter rodentium expressing Stx in a mouse model of Shiga toxin-producing E. Coli (STEC) infection. C. rodentium, a naturally occurring pathogen of laboratory mice which causes transmissible murine colonic hyperplasia, binds to the mouse enterocyte by a specific attachment and effacement lesion similar to that of EHEC. Strategies have been developed to lysogenize C. rodentium with antibiotic-marked Stx1- and Stx2-expressing bacteriophages as well as to express toxin components from plasmid vectors. Toxin production, phage induction, and lysogen stability will be evaluated in vitro. Mice will be challenged with toxin-producing C. rodentium and evaluated for clinical and pathologic signs of disease. This model has the potential of reproducing both the gastrointestinal and renal injury seen in EHEC infection, allows the use of adult animals and the development of normal immune responses, utilizes the power of mouse genetics to investigate genetic factors in determining gastrointestinal (GI) and systemic disease expression, and provides a significant increase in the ease of identifying and testing new interventions compared to many other animal models. 2. Expression of nontoxic Stx1 and Stx2 antigens using a balanced lethal plasmid system in Vibrio cholerae vaccine strains. Vibrio cholerae will be used as a live oral attenuated vaccine vector to deliver immunogenic antigens of EHEC to stimulate a common mucosal immune response. A balanced lethal plasmid system will be used to provide stable expression of the heterologous antigens from the vaccine strains. The germfree mouse model of V. cholerae colonization will be used to examine mucosal and systemic immune responses to the toxin components expressed by the vector strains. The new mouse challenge model will be compared to prior mouse models in evaluating protection from disease in response to immunization with V. cholerae strains expressing the EHEC antigens.

描述（改编自应用程序） 胃肠道疾病及肾损伤的调查 肠出血性大肠杆菌 (EHEC) 及其开发和测试 预防感染后疾病的干预措施受到以下因素的阻碍： 缺乏有效复制典型人类特征的便捷动物模型 进展为 HUS 的结肠疾病。首席研究员建议 开发一种新的肠出血性大肠杆菌感染小鼠模型，以实现长期目标 提高研究疾病发病机制和预防的能力。新的 动物模型将与现有模型进行比较以评估疫苗 对抗肠出血性大肠杆菌的策略。这将通过以下两个方面来完成 具体目标： 1. 表达 Stx 的啮齿类柠檬酸杆菌的使用评价 在产志贺毒素大肠杆菌（STEC）感染的小鼠模型中。 C. 啮齿类动物，一种实验室小鼠自然产生的病原体，可导致 传染性小鼠结肠增生，通过a与小鼠肠上皮细胞结合 特定的附着和消失病变与肠出血性大肠杆菌相似。策略 已开发出用抗生素标记的 Stx1- 来溶原 C. rodentium 和 表达 Stx2 的噬菌体以及表达毒素成分的噬菌体 质粒载体。毒素产生、噬菌体诱导和溶原稳定性将 进行体外评估。小鼠将受到产生毒素的梭菌的挑战。 啮齿类动物并评估疾病的临床和病理体征。这 该模型具有复制胃肠道和肾脏的潜力 EHEC 感染中出现的损伤，允许使用成年动物和 正常免疫反应的发展，利用小鼠遗传学的力量 研究决定胃肠道 (GI) 和全身性的遗传因素 疾病表达，并提供了显着增加的容易性 与许多其他动物模型相比，识别和测试新的干预措施。 2. 使用平衡致死表达无毒 Stx1 和 Stx2 抗原 霍乱弧菌疫苗株中的质粒系统。将使用霍乱弧菌 作为活的口服减毒疫苗载体来传递免疫原性抗原 EHEC 可刺激常见的粘膜免疫反应。平衡致死质粒 系统将用于提供异源抗原的稳定表达 来自疫苗株。霍乱弧菌定植的无菌小鼠模型 将用于检查对毒素的粘膜和全身免疫反应 由载体菌株表达的成分。新的老鼠挑战模型将 与之前的小鼠模型进行比较，以评估对疾病的保护作用 对表达 EHEC 抗原的霍乱弧菌菌株免疫的反应。