A NONHUMAN PRIMATE MODEL OF RICKETTSIA PROWAZEKII INFECTION (EPIDEMIC TYPHUS)

普瓦泽克立克次体感染（流行性斑疹伤寒）的非人类灵长类动物模型

• 批准号: 8173017
• 负责人: CHAD J. ROY
• 金额: $ 6.18万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8173017
• 关键词: Accounting; Acute; Aerosols; Affect; Albumins; Animals; Anorexia; Appearance; Area; Arts; B-Lymphocytes; Biological; Blood Glucose; Blood Urea Nitrogen; Blood Vessels; Body Weight decreased; Brain; CD11 Antigens; CD14 gene; CD3 Antigens; CD8-Positive T-Lymphocytes; Cardiovascular system; Cell Count; Cells; Cerebral cortex; Characteristics; Chinese People; Chronic; Circadian Rhythms; Clinical; Clinical Chemistry; Computer Retrieval of Information on Scientific Projects Database; Data; Dendritic Cells; Development; Disease; Disease model; Dose; Drops; Edema; Environment; Epidemic; Euthanasia; Exposure to; Eye; Feces; Fever; Funding; Future; Globulins; Goals; Grant; Hematology; Homeostasis; Hour; Human; IL3RA gene; Immune; Immune response; Immunologics; Infection; Inflammation; Institution; Intravenous; Lesion; Lice; Liver; Lung; Lymphocyte; Lymphocyte Subset; MS4A1 gene; Macaca mulatta; Malaise; Measurement; Membrane; Mental Depression; Methodology; Microglia; Modeling; Monitor; Mucous body substance; Natural Killer Cells; Neuraxis; Nodule; Pathologic; Pathology; Physiological; Primates; Recording of previous events; Relative (related person); Reporting; Research; Research Personnel; Resources; Rickettsia prowazekii; Route; Safety; Source; Staining method; Stains; Symptoms; Syndrome; System; Temperature; Testing; Thick; Time; Tissues; Typhus; United States National Institutes of Health; Up-Regulation; Vaccines; Vasculitis; Weight; base; body system; calreticulin; dosage; experience; human disease; improved; lymphoid hyperplasia; model development; monocyte; neutrophil; new product development; nonhuman primate; peripheral blood; protective efficacy; response; trend; vascular inflammation; vector; weapons

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Rickettsia prowazekii is the causative agent of epidemic typhus, a vector (louse)-borne disease characterized by a sudden onset of febrile symptoms with significant pathologic sequelae. In addition to causing epidemic disease in poor and unhygienic environments, R. prowazekii has also been identified as possessing the characteristics of a biological weapon. There presently is no vaccine available for protection against epidemic typhus, although development of new products is currently underway. A fully characterized primate model of disease is needed to determine immune response, safety, and protective efficacy of vaccine products developed to protect against R. prowazekii infection. The goal of this project is to develop a robust nonhuman model of disease for epidemic typhus in order to accelerate testing of newly developed vaccine products. The specific hypothesis is that use of the Rhesus macaque (Macaca mulatta) of Chinese origin will provide an optimal test system for an infection model of epidemic typhus. We base this hypothesis upon the observations from limited past studies that detailed 1) a clear dose-response relationship in prior model development efforts with the Breinl strain using Rhesus macaques when directly compared to experimental infection with avirulent strains, and 2) typical pathology in the form of disseminated vasculitis including typhus nodules in the central nervous system that emulated the human clinical syndrome. Based on these observations, the experimental focus of this proposal is on the model development of epidemic typhus in the Rhesus macaque. The specific aims are to: 1. Reestablish a nonhuman primate model for intravenous R. prowazekii infection. Studies over 25 years ago reported on model development of R. prowazekii infection in the nonhuman primate without the benefit of advances in immunologic and physiologic measurement. We will utilize the state of the art methodology during experimental infection to achieve precise account of biological response in infected animals. This will reestablish the model in the context of immune and pathologic response for future nonhuman primate studies involving R. prowazekii infection. 2. Develop an aerosol challenge model R. prowazekii challenge. Rickettsia prowazekii, in addition to causing epidemic disease, is considered a biological threat agent because of its low dose, aerosol infectivity and history of weaponization. As such, new products must provide protective efficacy against a realistic aerosol challenge. Clinical and immunologic parameters obtained from the IV Rickettsia prowazekii infections will serve as a guide to development of the aerosol model of disease. The aerosol disease model will provide an optimal system for testing of products developed expressly for protective efficacy against potential mucosal challenge with R. prowazekii. Six rhesus macaques were exposed intravenously to Breinl strain of Rickettsia prowazekii. Three groups (n=2) were administered graduated doses from 2.5E+04 to 1.0E+06 PFU. All animals became clinically ill two to three days postexposure; noted signs included depression, anorexia, weakness, and general malaise. Changes in stool were also noted. Local edema and thick discharge was observed in the mucus membranes (eyes) of three of the four animals 96 hours postexposure. Clinical signs improved over the next 5-7 days postexposure with a return to clinically normal appearance thereafter. Mild anorexia was the only lasting clinical sign that endured for up to 14 days postexposure. Subsequently, all animals experienced significant weight loss postexposure of between 10-15% of preexposure weight. Weights of three of the four animals gradually returned to preexposure weights. Telemetric monitoring of animals showed acute core temperature spikes of up to +2.5 degrees centigrade in all animals for up to 96 hours postexposure, gradually returning to homeostasis, although without a return to normal diurnal variation. Gradual increase in core temperature was observed thereafter (from day 10-30) postexposure; low grade (+1.0-1.5 degrees centigrade) fever was observed in all animals (4/4) to day 30. Similarly, disturbances in cardiovascular rhythm was recorded. Clinical chemistries of peripheral blood showed initial decreases of globulin, blood urea nitrogen, and blood glucose in all animals exposed. Increases in albumin, abumin-globulin ratio, and calreticulin were also observed. All animals initially showed a dramatic drop in circulating neutrophils and monocytes and concurrent increase in lymphocytes +5 days postexposure. Neutrophils gradually increased +20 days postexposure, with lymphocytes and monocytes declining to below normal levels by the time of euthanasia. Exposed animals also showed a dose-dependent increase in CD3+ and CD8+ lymphocytes +10 days postexposure. Both animals administered 1.0E+06 PFU showed dramatic increases in CD20+ B cells relative to the lower dosage group; CD14+ monocytes also increased in these animals +10 days postexposure. Total NK cell counts increased in all animals exposed; CD11+ dendritic cells also increased in all animals while the CD123+ count of dendritic cells decreased. Histopathological analysis of tissues from infected animals indicated mild lymphoid hyperplasia and mild chronic inflammation throughout the major organ systems. Animals exposed to the higher inoculating dose (1.0E+06 PFU) showed both lymphoid hyperplasia and chronic inflammation in the brain, lung, and liver that was consistent with previously described pathology associated with typhus infection. Chronic focal inflammation and vascular lesions in the cerebral cortex were noted in both of these animals. Further analysis of the brain showed the presence of R. prowazekii in areas with vascular lesions and upregulating of CD163 on microglia. These stains were colocalized with Ab-CD163 which also indicated upregulation of CD163 in many of the microglia affected. The increased presence of the double-stained positive cells was observed as a dose dependent phenomenon. Thus far, the results from the model development studies are positive in that we have observed dose-dependent changes associated with experimental infection of R. prowazekii in rhesus macaques. The preliminary results from the IV exposures showed clinical illness characterized by many of the signs associated with the human disease, including core temperature and cardiovascular system alternation during active infection. Similarly, clinical chemistry and hematology values changed dramatically when infected, showing many of the same trends observed in previous studies involving R. prowazekii and nonhuman primates. Advanced analysis of peripheral blood also showed increases in particular lymphocyte subpopulations in response to infection. Pathologically, animals at the highest inoculating dose (1.0E+06 PFU) showed disease-specific chronic focal inflammation in the form of vascular lesions in the brain; a noted hallmark of R. prowazekii infection. Taken together, these preliminary results have shown that the rhesus macaque is susceptible to IV infection with R. prowazekii. These data will provide baseline infection data in future studies where IV exposure is appropriate and serve as a basis for model development studies employing an alternative route of exposure to study infection.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 人力体prowazekii是流行病的病因，流行病（一种载体（虱子）疾病，其特征是突然发作的发热症状，具有明显的病理后遗症。 除了在贫穷和不卫生的环境中引起流行病外，R. prowazekii还被确定为具有生物武器的特征。 目前，尽管目前正在开发新产品，但目前尚无疫苗可用于防止流行病。 需要一个完全表征的疾病灵长类动物模型来确定开发的疫苗产品的免疫反应，安全性和保护性疗效，以防止R. prowazekii感染。 该项目的目的是为流行病的疾病开发强大的非人类疾病模型，以加速对新开发的疫苗产品的测试。 具体假设是，中国起源的恒河猴（Macaca mulatta）的使用将为流行病的感染模型提供最佳的测试系统。 我们基于有限的过去研究的观察结果，这些假设详细介绍了1）在先前的模型开发工作中与breinl菌株的剂量反应关系，使用恒河猕猴直接与无毒菌株进行实验感染，而2）典型的病理学，以及典型的病理学，在包括typhus nodules的传播血管炎的形式中，包括中心神经系统中的人类人类临床中的中心神经临床。 基于这些观察结果，该建议的实验重点是恒河猕猴流行病的模型发展。 具体目的是：1。重建静脉注射R. prowazekii感染的非人类灵长类动物模型。 25年前的研究报道了非人类灵长类动物中普罗瓦西科感染的模型开发，而没有免疫学和生理测量的进步。 我们将在实验感染期间利用艺术方法的状态，以精确地说明感染动物的生物反应。 这将在免疫和病理反应的背景下重新建立该模型，以涉及未来的非人类灵长类动物研究。 2。开发一种气溶胶挑战模型R. Prowazekii挑战。人力车prowazekii除了引起流行病外，由于其低剂量，气溶胶感染力和武器化病史而被认为是生物威胁剂。 因此，新产品必须针对现实的气溶胶挑战提供保护功效。 从IV Rickettsia Prowazekii感染获得的临床和免疫学参数将作为气溶胶模型的发展指南。 气溶胶疾病模型将提供一个最佳的系统，用于测试为针对潜在的Prowazekii潜在粘膜挑战而开发的产品。 静脉内将六个恒河猕猴暴露于Rickettsia prowazekii的Breinl菌株。 将三组（n = 2）从2.5e+04到1.0E+06 PFU施用。 暴露后两到三天，所有动物都在临床上生病。著名的迹象包括抑郁症，厌食症，弱点和一般不适。 还注意到粪便的变化。 在暴露后96小时的四只动物中，三只动物中有三只动物的粘膜（眼睛）观察到局部水肿和厚厚的排放。 暴露后接下来的5-7天，临床体征改善，此后恢复临床正常外观。 轻度厌食症是暴露后长达14天的唯一持久临床体征。 随后，所有动物的暴露后暴露于10-15％的体重。 四只动物中三只动物的重量逐渐恢复为预遭受的重量。 对动物的远程监测显示，所有动物的急性核心温度峰值在暴露后96小时内均高达+2.5度，逐渐恢复到体内平衡，尽管没有恢复正常的昼夜变化。 此后暴露后（从第10-30天）观察到核心温度的逐渐升高；在所有动物（4/4）到第30天，都观察到低年级（+1.0-1.5摄氏度）发烧。同样，记录了心血管节奏的障碍。 外周血的临床化学表现显示出暴露于所有动物的球蛋白，血液尿素氮和血糖的初始降低。 还观察到了白蛋白，ABUMIN-球蛋白比和钙网蛋白的增加。 最初，所有动物均显示出循环中性粒细胞和单核细胞的急剧下降，并且暴露后淋巴细胞同时增加。 暴露后暴露后嗜中性粒细胞逐渐增加 +20天，到安乐死时，淋巴细胞和单核细胞下降到正常水平以下。 暴露的动物还显示出暴露后CD3+和CD8+淋巴细胞+10天的剂量依赖性增加。 两种施用1.0E+ 06 PFU的动物均相对于下剂量组的CD20+ B细胞均显示出急剧增加。暴露后这些动物中CD14 +单核细胞也增加了+10天。 所有暴露的动物中NK细胞计数的增加；所有动物的CD11+树突状细胞也增加，而树突状细胞的CD123+计数也降低。 对受感染动物的组织的组织病理学分析表明，整个主要器官系统中都有轻度的淋巴增生和轻度的慢性炎症。 暴露于较高接种剂量（1.0E+06 PFU）的动物在大脑，肺和肝脏中均表现出淋巴性增生和慢性炎症，这与先前描述的与Typhus感染相关的病理一致。 这两种动物都注意到大脑皮层中的慢性局灶性炎症和血管病变。 对大脑的进一步分析表明，在血管病变和小胶质细胞上CD163上调的区域中存在R. prowazekii。 这些污渍与AB-CD163共定位，这也表明在许多受影响的小胶质细胞中CD163上调。 观察到双染色阳性细胞的存在增加是剂量依赖性现象。 到目前为止，模型开发研究的结果是积极的，因为我们已经观察到与恒河猕猴中prowazekii的实验感染相关的剂量依赖性变化。 IV暴露的初步结果表明，临床疾病的特征是与人类疾病有关的许多迹象，包括核心温度和心血管系统在主动感染过程中的交替。 同样，在感染时，临床化学和血液学值发生了巨大变化，显示了先前涉及prowazekii和非人类灵长类动物的研究中观察到的许多相同趋势。 外周血的先进分析还显示出响应感染的淋巴细胞亚群的增加。 从病理上讲，以最高接种剂量的动物（1.0E+06 PFU）显示出疾病特异性的慢性局灶性炎症，以大脑的血管病变形式形式。 R. Prowazekii感染的著名标志。 综上所述，这些初步结果表明，恒河猕猴易受静脉注射的prowazekii感染。 这些数据将在未来的研究中提供基线感染数据，在未来的研究中，静脉注射是合适的，并作为模型开发研究的基础，采用替代性暴露于研究感染的途径。