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

了解细胞免疫反应清除病毒的能力 伯氏疏螺旋体（Borrelia burgdorferi）是莱姆病的病原体，对于 正确理解莱姆病的发病机制。我们已经展示了 此前，巨噬细胞迅速吞噬并杀死伯氏疏螺旋体 体外。 尽管有这种杀伤作用，我们还是观察到偶尔的细胞相关 持久性螺旋体和此类螺旋体已被重新培养。离体， 我们从未发炎的腹膜腔中分离出螺旋体 尽管存在常驻巨噬细胞，但仍长期感染的小鼠。我们 将在三个阶段检查体内正常杀伤机制的失败 方式：体外、离体和原位。我们的方法包括 生化测定以及定量共焦荧光和电子 显微镜。 具体来说，在目标 1 中，我们将确定动力学、范围和机制 体外吞噬细胞杀死伯氏疏螺旋体是必要的第一步 目标 2 步骤：测试腹腔巨噬细胞的杀伤能力 在存在或不存在的情况下从伯氏疏螺旋体感染的小鼠中分离出来 灌洗液可能含有免疫调节成分。 万一 持久性螺旋体的特征是其 如果清除错误，我们还将检查分离出的未培养的螺旋体 通过免疫荧光和电子显微镜从受感染的动物中检测 表达的表面蛋白的标记。 最后，在目标 3 中，我们将学习 使用莱姆疏螺旋体病的心脏受累现场提出这些问题， 用于这些目的的理想疾病表现，因为病变 问题似乎主要是巨噬细胞介导的。我们将检查 受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螺旋体 心；确定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 巨噬细胞与细胞因子的活化可以影响 莱姆心脏炎的进展，具有明显治疗前景 影响。总的来说，我们希望这些研究能够提供一个 吞噬细胞功能完整性的全面描述 感染伯氏疏螺旋体的宿主。

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.