权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The Heart of OspC as a Borrelia burgdorferi Adhesin

作为伯氏疏螺旋体粘附素的 OspC 核心

基本信息

批准号：
7785567
负责人：
Jenifer L Coburn
金额：
$ 19万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-03-01 至 2012-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7785567
关键词：
Adhesions Affect Alleles Amino Acids Animals Antibiotic Therapy Antibodies Bacteria Bacterial Adhesins Bacteriophages Binding Biochemical Bite Bladder Blood Borrelia Borrelia burgdorferi Buffers Cardiac Cell Culture Techniques Cell Surface Receptors Cell physiology Cells Charge Core Protein DBL Oncoprotein DNA Data Data Set Disaccharides Disease Endothelium Environment Epicardium Future Glycosaminoglycans Goals Harvest Health system Heart Human Human Cell Line Immune response Immune system In Vitro Infection Injection of therapeutic agent Inovirus Integrins Investigation Joints Laboratories Lead Libraries Life Ligands Light Lipoproteins Lyme Disease Mammalian Cell Mammals Measures Membrane Proteins Mus Mutate Myocardium Nature Nervous system structure Neurologic Order Spirochaetales Organism OspC protein Perfusion Phage Display Phase Polymers Process Protein Fragment Proteins Proteoglycan Recombinants Regulation Role Rosa Signal Transduction Site Site-Directed Mutagenesis Skin Staging Surface Tail Testing Therapeutic Ticks Time Tissues Veins Work base design epimerization extracellular in vitro activity in vivo insight interest mutant particle public health relevance receptor research study sulfation tool vector

项目摘要

DESCRIPTION (provided by applicant): Borrelia burgdorferi, the causative agent of Lyme disease, establishes persistent infection that can affect the joints, heart, skin, and nervous system. The ability of this spirochete to establish infection demands 1) dissemination from the site of inoculation by an infected tick, 2) adaptation to the mammalian environment, and 3) persistence despite the host immune response. Interactions with mammalian cells occur continually during each of these steps and phases of infection. Using a phage display selection in vitro, we showed that the B. burgdorferi outer membrane protein, P66, binds to the 3-chain integrins. In an in vivo phage display selection, we also showed that OspC serves as an adhesin to an unknown receptor in the endothelium in living mice. Phage clones bearing OspC sequences were the single group most highly selected in vivo, and most of the clones were selected in the heart. OspC is a protein of the Lyme disease Borrelia that is expressed as the bacteria move from tick to mammal, and was previously shown by another group to be critical for the earliest stages of infection of mice. A different group showed that a deficiency in OspC could be partially overcome in scid mice by over-expression of other lipoproteins. This work also revealed that OspC does appear to be essential for normal dissemination of the bacteria to the heart, the tissue in which our phage clones were most frequently selected. Our data are also consistent with previous work by a third group demonstrating that B. burgdorferi in the heart express higher levels of ospC than do the bacteria in other tissues tested. Our overall hypothesis is that the adhesin activity of OspC is important to its critical function in the life of B. burgdorferi. Based on our results as well as those of the three other groups, we will test two facets of this hypothesis in this proposal. The first is that OspC recognizes a receptor localized in regions of the heart colonized by B. burgdorferi. The second is that specific conserved amino acids are required for adhesin activity and normal function in establishment of disseminated infection in mice. B. burgdorferi strains that do and do not express OspC will be tested for adhesion activity in cell culture and targeting of the heart, and particular regions therein, in mice. Additional strains expressing mutated alleles of OspC will be generated and tested using the same approaches. In this set of experiments we propose to employ our unique tools to further define, at the biochemical level, the role of OspC in B. burgdorferi infection. We anticipate that this work may enable the design of therapeutic approaches to halt dissemination of B. burgdorferi after the tick bite even in unvaccinated people and animals. PUBLIC HEALTH RELEVANCE: Lyme disease is now the most prevalent vector-borne illness in the northern hemisphere, and a significant burden on the health system in regions in which it is common due to neurologic, cardiac, and rheumatologic manifestations of disease. We propose to delve into how Borrelia burgdorferi interacts with the heart in a mammalian host. We will focus on one B. burgdorferi protein, OspC, which is essential for the bacteria to cause the normal disseminated infection in mice. Our overall goal is to understand how OspC recognition of host cell molecules allows B. burgdorferi to overcome host barriers to the establishment of persistent, disseminated infection, which could eventually lead to strategies that will help the host immune system clear the organism as adjuncts to antibiotic therapy.

描述（由申请人提供）：莱姆病的病原体伯氏疏螺旋体可引起持续性感染，影响关节、心脏、皮肤和神经系统。这种螺旋体建立感染的能力需要1）从接种部位传播感染蜱，2）适应哺乳动物环境，3）尽管宿主免疫反应，但持续存在。与哺乳动物细胞的相互作用在感染的每个步骤和阶段中不断发生。利用体外噬菌体展示筛选，我们发现B。burgdorferi外膜蛋白P66与3链整联蛋白结合。在体内噬菌体展示选择中，我们还表明OspC在活小鼠的内皮中作为未知受体的粘附素。携带OspC序列的噬菌体克隆是体内选择最高的单一组，并且大多数克隆在心脏中选择。OspC是莱姆病疏螺旋体的一种蛋白质，随着细菌从蜱虫转移到哺乳动物而表达，并且先前被另一个小组证明对小鼠感染的最早阶段至关重要。另一个研究小组发现，scid小鼠中OspC的缺乏可以通过其他脂蛋白的过度表达来部分克服。这项工作还表明，OspC似乎对细菌向心脏的正常传播至关重要，心脏是我们的噬菌体克隆最常被选择的组织。我们的数据也与第三组先前的工作一致，表明B。心脏中的伯氏菌比其他测试组织中的细菌表达更高水平的ospC。我们的总体假设是OspC的粘附素活性对其在B生命中的关键功能是重要的。burgdorferi。根据我们的研究结果以及其他三个小组的研究结果，我们将在本提案中检验这一假设的两个方面。第一个是OspC识别位于心脏被B定殖的区域中的受体。burgdorferi。第二，在小鼠播散性感染的建立中，粘附素活性和正常功能需要特定的保守氨基酸。B。将测试表达和不表达OspC的伯氏菌株在细胞培养物中的粘附活性和对小鼠心脏及其特定区域的靶向。将使用相同的方法产生和测试表达OspC的突变等位基因的另外的菌株。在这组实验中，我们建议使用我们独特的工具，以进一步定义，在生物化学水平上，OspC在B中的作用。伯氏感染我们预计这项工作可能使治疗方法的设计，以阻止传播的B。即使在未接种疫苗的人和动物中，蜱虫叮咬后也会发生伯氏螺旋体感染。公共卫生相关性：莱姆病目前是北方最流行的病媒传播疾病，并且由于疾病的神经、心脏和风湿病表现，在莱姆病常见的地区，莱姆病是卫生系统的重大负担。我们建议深入研究伯氏疏螺旋体如何与哺乳动物宿主的心脏相互作用。我们将重点关注一个B。Burgdorferi蛋白，OspC，这是细菌在小鼠中引起正常播散性感染所必需的。我们的总体目标是了解OspC识别宿主细胞分子如何允许B。Burgdorferi克服宿主障碍，建立持续性，传播性感染，这可能最终导致策略，将有助于宿主免疫系统清除生物体作为抗生素治疗的免疫原。