Virulence Mechanisms of Multifunctional Borrelial Proteins

多功能疏螺旋体蛋白的毒力机制

基本信息

批准号：
10407450
负责人：
Brandon Lee Garcia
金额：
$ 72.31万
依托单位：
EAST CAROLINA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-06-15 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10407450
关键词：
Address Affinity Amino Acids Animal Model Antibodies Asia Bacteria Binding Biochemical Biological Assay Biophysics Borrelia Borrelia Infections Borrelia afzelii Borrelia burgdorferi Borrelia burgdorferi Group Borrelia garinii Borrelia miyamotoi Borrelia turicatae Classical Complement Pathway Clinical Communicable Diseases Complement Complement 1q Complement Activation Complement component C1r Complex Crystallization Cytolysis Data Disease Disease model Etiology Europe Event Experimental Models Family Genes Genetic Goals Hematogenous Homologous Gene Hot Spot Human Immune Immunity Immunocompetent Immunomodulators Impairment In Vitro Infection Lipoproteins Lyme Disease Lytic Measures Mediating Medical Microbe Microbiology Minor Modeling Molecular Mus Natural Immunity Nature Order Spirochaetales Orthologous Gene Pathogenesis Pathway interactions Pattern Recognition Peptide Hydrolases Phenotype Phylogenetic Analysis Play Proteins Reaction Relapsing Fever Reporting Resolution Role Serum Spirochaetales Infections Structure Surface Testing Ticks United States Vector-transmitted infectious disease Virulence X-Ray Crystallography arm biophysical techniques complement pathway complement system design experimental study human disease imaging approach immunoregulation in vitro activity in vivo in vivo Model in vivo imaging inhibitor interdisciplinary approach lyme pathogenesis mouse model multidisciplinary mutant pathogen relapsing fever borrelia tick borne spirochete vector-borne vector-borne pathogen

项目摘要

PROJECT SUMMARY Spirochetes of the Borrelia genus are the cause of several prevalent vector-borne diseases. The most well-known pathogen from this group is Borrelia burgdorferi sensu stricto, which causes over 300,000 cases of Lyme disease in the United States each year. B. garinii and B. afzelii, which belong to the B. burgdorferi sensu lato complex, are the primary agent of Lyme disease in Europe and Asia. Borrelia spirochetes are also the etiological agent of the ancient human disease relapsing fever, as well as a newly recognized infectious condition called Borrelia miyamotoi disease. Lyme-associated, relapsing fever-associated, and B. miyamotoi spirochetes have differing lifecycles and their infections are accompanied by distinct clinical presentations. However, each of these pathogens are known to encode multifunctional surface-expressed lipoproteins that interact with vertebrate host molecules. Among these proteins are a small arsenal of immunomodulators that specifically target and inactivate a primary arm of innate immunity known as the complement system. We have recently reported two independent lines of evidence that support the hypothesis that one of these pathways, known as the classical pathway, is important in controlling B. burgdorferi infections. First, we have shown that mice deficient in the pattern recognition molecule of the classical pathway, C1q, are significantly more susceptible to B. burgdorferi infection. Secondly, we have shown that the lipoprotein B. burgdorferi BBK32 is a high-affinity inhibitor of the initiating protease of the classical pathway, C1r. In Aim 1 of this project we seek to understand the C1r inhibitory activity of BBK32 sensu lato proteins at the molecular level. In Aim 2 we will determine the immunomodulatory roles and virulence contribution of three BBK32 orthologues known as FbpA, FbpB, and FbpC which are found uniquely in relapsing fever and B. miyamotoi spirochetes. In Aim 3 we will delineate the role of C1r inhibition in borrelial pathogenesis using in vivo models of disease. To achieve this, we propose a multi-disciplinary strategy that employs x-ray crystallography, biophysical approaches, and complement functional assays to pinpoint key ‘hot-spot’ residues on BBK32 that give rise to its potent anti-C1r activity. These data will inform the design of bbk32 mutants which will be used in mouse infectivity studies to connect structural features of BBK32, at the amino-acid level, to an in vivo phenotype. Parallel studies will use genetic deletion mutants of fbp genes from the relapsing fever- associated spirochetes B. turicatae and B. hermsii. These studies will be paired with experimental models of Lyme and relapsing fever borrelioses using C1r-/- mice to better understand the role of the classical pathway initiating protease in the control of borrelial infections. By addressing fundamental questions of how medically important Borrelia spirochetes recognize and evade host immunity, the studies proposed here stand to have a broad and significant impact on the field of bacterial pathogenesis.

项目摘要伯罗利属的螺旋体是几种普遍的载体传播疾病的原因。最多该组众所周知的病原体是Borrelia burgdorferi sensu stricto，它导致30万例每年在美国莱姆病。 B. Garinii和B. Afzelii，属于B. burgdorferi sensu LATO综合体是欧洲和亚洲莱姆病的主要药物。伯氏螺旋体也是古代人类疾病的病因学药，以及新认可的感染力疾病称为宫林氏菌病。莱姆相关，继电器发烧相关和宫本芽孢杆菌螺旋体具有不同的生命周期，其感染是通过不同的临床表现来完成的。但是，已知这些病原体中的每一个都编码多功能表达表达的脂蛋白与脊椎动物宿主分子相互作用。这些蛋白质中有一小部分免疫调节剂特别针对和灭活了先天免疫的主要部门，称为完成系统。我们有最近报道了两条独立的证据，这些证据支持以下假设。被称为经典途径，对于控制伯氏芽孢杆菌感染很重要。首先，我们已经表明经典途径C1q的模式识别分子缺乏的小鼠明显更多容易受到B. burgdorferi感染的影响。其次，我们已经证明了脂蛋白B. burgdorferi bbk32是一个经典途径启动蛋白酶的高亲和力抑制剂，C1R。在该项目的目标1中，我们试图了解BBK32 Sensu Lato蛋白的C1R抑制活性分子水平。在AIM 2中，我们将确定三个的免疫调节作用和病毒贡献 BBK32直系同源物称为FBPA，FBPB和FBPC，它们在复发性发烧和B中独特地发现。 Miyamotoi螺旋体。在AIM 3中，我们将描述C1R抑制在使用IN中的骨质发病机理中的作用体内疾病模型。为了实现这一目标，我们提出了一种雇员X射线的多学科策略晶体学，生物物理方法和补充功能测定，以查明钥匙“热点”残差在BBK32上引起其潜在的抗C1R活性。这些数据将为BBK32突变体的设计提供信息将用于小鼠感染研究中，以将BBK32的结构特征（在氨基酸水平）连接到体内表型。平行研究将使用复发性发烧中的FBP基因的遗传缺失突变体相关的螺旋体B. turicatae和B. hermsii。这些研究将与使用C1R - / - 小鼠更好地了解经典途径的作用在控制疏松症感染的控制中引发蛋白酶。通过解决有关如何在医学上的基本问题重要的Borrelia螺旋体认识并逃避了宿主免疫，此处提出的研究具有对细菌发病机理领域的广泛而显着影响。