Mouse Models for EHEC Disease

肠出血性大肠杆菌疾病小鼠模型

• 批准号: 6760429
• 负责人: SALVATORE A CILMI
• 金额: $ 12.53万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6760429
• 关键词: Escherichia coli 0157:H7; Escherichia coli infections; disease /disorder model; disease /disorder prevention /control; enzyme linked immunosorbent assay; gastrointestinal infection; histopathology; kidney infection; laboratory mouse; light microscopy; model design /development; pathologic process; phlebotomy; polymerase chain reaction; shiga toxin

DESCRIPTION (provided by applicant): Understanding of the pathogenesis of enterohemorrhagic E. coli (EHEC) infection has been hindered by the lack of an animal model that effectively reproduces the typical human colonic disease that progresses to the hemolytic-uremic syndrome (HUS). A variety of animal models have been developed to facilitate the study of the gastrointestinal disease or the renal disease caused by these organisms, but not both. These models have disadvantages, including the difficulties of working with infant or gnotobiotic animals, the lack of responsiveness to certain EHEC strains, and the requirement of specific interventions, such as antibiotic treatment prior to animal infection, which add artificial steps to the model. We propose to increase the understanding of disease pathogenesis by developing new mouse models of EHEC infection. Specific Aim 1. Evaluation of the use of Citrobacter rodentium expressing Slliga toxin (Stx) in a mouse model of EI-I.C infection. C. rodentium is a naturally occurring pathogen of laboratory mice, causing transmissible murine colonic hyperplasia. Colonic histopathology of mice infected with C. rodentium show the typical attachment and effacement (A/E) lesion seen in EHEC infection. Strategies have been developed to lysogenize C. rodentium with antibiotic-marked Stxl-, Stx2-, and hybrid Stx-expressing bacteriophages. Toxin production, phage induction, and lysogen stability will be examined in vitro. Mice will be challenged with Stx-producing C. rodentium and will be evaluated for clinical and histopathologic signs of disease. This model has the potential for reproducing both the gastrointestinal and renal injury seen in human disease and for using mouse genetics to examine host factors in the development of EHEC disease. A mouse model would increase our ability to test the efficacy of new therapeutics against EHEC infection. Specific Aim 2. Evaluation of the use of globotriaosylceramide (Gb3)-over expressing mice as a mouse model for ENEC infection. Gb3 is the receptor for Stx. We hypothesize that over expression of Gb3 in the mouse will cause increased sensitivity to Stx. We propose to examine the clinical response and histopathology of Gb3-overexpressing mice injected with purified toxin and infected with toxin-producing strains of E. coli and C. rodentium and to develop this strain as a model for studying the pathogenesis and prevention of EHEC disease.

描述（由申请人提供）：由于缺乏有效再现典型人类结肠疾病并进展为溶血性尿毒症综合征（HUS）的动物模型，阻碍了对肠出血性大肠杆菌（EHEC）感染发病机制的理解。已经开发了多种动物模型来促进对这些生物体引起的胃肠道疾病或肾脏疾病的研究，但不能同时研究两者。这些模型存在缺点，包括难以使用婴儿或无菌动物、对某些肠出血性大肠杆菌菌株缺乏反应性，以及需要特定的干预措施，例如在动物感染之前进行抗生素治疗，这为模型增加了人为步骤。我们建议通过开发新的肠出血性大肠杆菌感染小鼠模型来增进对疾病发病机制的了解。具体目标 1. 评估表达 Slliga 毒素 (Stx) 的啮齿类柠檬酸杆菌在 EI-I.C 感染小鼠模型中的用途。啮齿类梭状芽胞杆菌是实验室小鼠天然存在的病原体，可引起传染性小鼠结肠增生。感染啮齿类弯曲杆菌的小鼠的结肠组织病理学显示出肠出血性大肠杆菌感染中典型的附着和消失（A/E）病变。已经开发出用抗生素标记的 Stx1、Stx2 和混合 Stx 表达噬菌体溶源啮齿类 C. 的策略。将在体外检查毒素产生、噬菌体诱导和溶原稳定性。小鼠将受到产生 Stx 的啮齿类弯曲杆菌的攻击，并将评估疾病的临床和组织病理学迹象。该模型有可能重现人类疾病中所见的胃肠道和肾脏损伤，并有可能利用小鼠遗传学来检查肠出血性大肠杆菌疾病发展中的宿主因素。小鼠模型将提高我们测试针对肠出血性大肠杆菌感染的新疗法的功效的能力。具体目标 2. 评估使用过度表达三酰神经酰胺 (Gb3) 的小鼠作为 ENEC 感染的小鼠模型。 Gb3 是 Stx 的受体。我们假设小鼠中 Gb3 的过度表达会导致对 Stx 的敏感性增加。我们建议检查注射纯化毒素并感染大肠杆菌和啮齿类梭菌产毒素菌株的 Gb3 过表达小鼠的临床反应和组织病理学，并开发该菌株作为研究肠出血性大肠杆菌疾病发病机制和预防的模型。