HOST-PARASITE INTERACTIONS THAT DETERMINE THE RATE OF B BURGDORFERI IN VIVO

决定体内伯氏疏螺旋体比率的宿主-寄生虫相互作用

• 批准号: 6234977
• 负责人: STEPHEN E. MALAWISTA
• 金额: $ 24.63万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6234977
• 关键词: Borrelia; Lyme disease; bacterial antigens; bacterial endocarditis; cell mediated cytotoxicity; confocal scanning microscopy; fluorescence microscopy; free radical oxygen; heart cell; host organism interaction; immunofluorescence technique; laboratory mouse; leukocyte activation /transformation; macrophage; microorganism immunology; neutrophil; nitric oxide; phagocytosis; surface antigens; tissue /cell culture

Understanding the capacity of the cellular immune response to clear Borrelia burgdorferi, the etiologic agent of Lyme disease, is essential to a proper understanding of the pathogenesis of Lyme disease. We have shown previously that macrophages take up and kill B. burgdorferi rapidly in vitro. Despite this killing, we have observed occasional cell-associated persistent spirochetes and such spirochetes have been recultured. Ex vivo, we have isolated spirochetes from the uninflammed peritoneal cavity of chronically-infected mice despite the presence of resident macrophages. We will examine this failure of normal killing mechanisms in vivo in three ways: in vitro, ex vivo, and in situ. Our methodologies include biochemical assays and quantitative confocal fluorescent and electron microscopy. Specifically, in Aim 1 we will identify kinetics, extent, and mechanisms of killing of B. burgdorferi by phagocytes in vitro as a necessary first step to Aim 2: testing the killing capacity of peritoneal macrophages isolated from B. burgdorferi-infected mice, in the presence and absence of lavage fluid which may contain immunomodulatory elements. In case characteristics of the persistent spirochetes are responsible for their faulty clearance, we will also examine uncultured spirochetes isolated from infected animals, by immunofluorescent and electron microscopic labeling of expressed surface proteins. Finally, in Aim 3, we will study these questions in situ using the cardiac involvement of Lyme borreliosis, an ideal disease presentation for these purposes, as the lesion in question appears to be primarily macrophage-mediated. We will examine sections of cardiac and other tissue from infected mice and evaluate whether the macrophages are phagocytosing and degrading spirochetes in the heart; whether the macrophages are activated or deactivated as determined by a panel of marker antibodies; and finally, whether modifying the state of activation of the macrophages with cytokines can influence the progression of Lyme carditis, a prospect with obvious therapeutic implications. Taken as a whole, we expect these studies to provide a comprehensive picture of the functional integrity of phagocytic cells in a host infected with B. burgdorferi.

了解细胞免疫反应清除 莱姆病的病原体--伯氏疏螺旋体， 正确理解莱姆病的发病机理。我们已经表明 先前巨噬细胞摄取并杀死B。Burgdorferi迅速在 体外 尽管如此，我们还是观察到了偶尔的细胞相关的 持久性螺旋体和这种螺旋体已经被重新培养。离体， 我们已经从未发炎的腹膜腔中分离出螺旋体， 慢性感染的小鼠，尽管存在常驻巨噬细胞。我们 我将在三个实验中研究正常的体内杀伤机制的失败， 方法：体外、离体和原位。我们的方法包括 生化分析和定量共聚焦荧光和电子显微镜 显微镜 具体而言，在目标1中，我们将确定动力学，程度和机制 杀了B。作为必要的第一步， 目标2的步骤：测试腹腔巨噬细胞的杀伤能力 分离自B。在存在和不存在以下物质的情况下， 可能含有免疫调节成分的灌洗液。 如果 持久性螺旋体的特征是他们 错误清除，我们还将检查未培养的螺旋体分离 免疫荧光和电子显微镜 标记表达的表面蛋白。 最后，在目标3中，我们将研究 这些问题在原位使用莱姆疏螺旋体病的心脏受累， 一个理想的疾病表现为这些目的，作为病变， 问题似乎主要是巨噬细胞介导的。我们将研究 感染小鼠的心脏和其他组织切片，并评估 巨噬细胞是否吞噬和降解 心脏;巨噬细胞是否被激活或失活， 通过一组标记抗体;最后，是否修改状态 用细胞因子激活巨噬细胞可以影响 莱姆病研究进展--一个有明显治疗前景的前景 含义。总的来说，我们希望这些研究能提供一个 吞噬细胞功能完整性的全面图片， 感染了B的宿主。burgdorferi。