Functional Analyses of Borrelia burgdorferi Adhesins

伯氏疏螺旋体粘附素的功能分析

基本信息

批准号：
9402006
负责人：
George Chaconas
金额：
$ 65.65万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-01-15 至 2020-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9402006
关键词：
Adherence Adhesives Affect Alleles Bacteria Bacterial Adhesins Binding Biochemical Bite Blood Circulation Blood Vessels Borrelia Borrelia burgdorferi Cell Communication Cells Chronic Clinical Complement Complex Defect Dermatan Sulfate Development Disease Endothelial Cells Endothelium Exhibits Extracellular Matrix Extravasation Family Family member Fibronectins Genetic Genotype Geography Glycosaminoglycans Health system Heart Heparitin Sulfate Human Immunologic Surveillance In Vitro Infection Infectious Skin Diseases Integrin Binding Investigation Joints Laboratories Lead Ligands Lyme Disease Lymphocyte Mammalian Cell Mediating Mediation Membrane Proteins Microscopic Modeling Mus Nature Nervous system structure Organism Orthologous Gene OspC protein Pathway interactions Principal Investigator Process Property Protein Array Proteins Role Site Skin System Testing Therapeutic Intervention Ticks Tissues Vaccines Variant Vascular Endothelium Virulence Factors Work chronic infection decorin functional group gain of function human disease imaging approach in vivo in vivo Model insight loss of function mouse model mutant paralogous gene polysulfated glycosaminoglycan public health relevance receptor targeted treatment tissue tropism transmission process vector

项目摘要

DESCRIPTION (provided by applicant): Upon transmission by a vector tick, Lyme disease spirochetes can establish a local skin infection, then may disseminate further to multiple tissues. Interactions with mammalian cells and extracellular matrix (ECM) are critical for colonization of diverse sites, and many B. burgdorferi adhesins that bind to cells or extracellular matrix (ECM) have been identified. The large number of adhesins, as well as the sequence variability of some, is likely to promote chronic multisystem disease and contribute to the noted diversity of human Lyme disease. Understanding this infection is complicated by the diversity of target tissues, multifunctionality of adhesins, and complexity of colonization (e.g. bloodstream survival, vascular adherence, tissue invasion, and escape from immune surveillance). To organize the plethora of receptor-ligand interactions into a framework for understanding the multisystem nature of Lyme disease, the three collaborators have taken multi-faceted genetic, biochemical and imaging approaches to fully characterize known B. burgdorferi adhesins, to discover and validate new adhesins, and to probe the functions of the full repertoire of B. burgdorferi adhesins using in vitro and in vivo models. These approaches led to important new insights into the known adhesins DbpA, BBK32, and P66, and defined new adhesive functions for the OspF subfamily and for OspC, which was previously shown to be essential for full infectivity. We showed that DbpA and OspC variants are associated with different tissue tropisms, so strain-specific differences in the repertoire of adhesins may contribute to corresponding differences in clinical manifestations. We found that BBK32 and P66 have roles in vascular adherence and joint invasion, and the interactions they mediate with the vascular endothelium may reflect sequential activities analogous to those involved in lymphocyte transmigration. We hypothesize that B. burgdorferi utilizes a multitude of adhesins with distinct activities to negotiate successie steps in a multiphasic and multisystem infection. In addition, sequence variation of a subset of adhesins may promote colonization of distinct sites and contribute to strain-specific differences in tissue tropism and disease. To gain a detailed understanding of how the diverse host cell interactions mediated by the complex repertoire of B. burgdorferi adhesins coordinate vascular attachment, tissue invasion and long-term colonization of diverse tissues, we will use the power of B. burgdorferi genetic systems and diverse mouse infection models. We will expand and fully characterize B. burgdorferi adhesins that promote interactions with endothelium to define the adhesin-ligand interactions that are required for dissemination and long-term colonization of mouse tissues. We will also characterize the role of each of these interactions in promoting the multiple steps required to attach to the vascular endothelium, to transmigrate across this barrier to stably colonize tissue. The proposed work will organize complex adhesive pathways into functional groups that mediate discrete steps in the infectious processes that together result in systemic Lyme borreliosis and disseminated, persistent infection in the mouse.

描述（由申请人提供）：经媒介蜱传播后，莱姆病螺旋体可引起局部皮肤感染，然后可能进一步传播至多个组织。与哺乳动物细胞和细胞外基质（ECM）的相互作用对于不同位点的定植至关重要，并且许多与细胞或细胞外基质（ECM）结合的伯氏疏螺旋体粘附素已被鉴定出大量的粘附素以及序列变异性。其中一些可能会促进慢性多系统疾病，并导致人类莱姆病的多样性，因为靶组织的多样性、粘附素的多功能性和定植的复杂性使理解这种感染变得复杂。（例如血流存活率，为了将大量的受体-配体相互作用组织成一个框架来理解莱姆病的多系统性质，三位合作者采用了多方面的遗传、生化和成像方法来充分研究。表征已知的伯氏疏螺旋体粘附素，发现和验证新的粘附素，并使用体外和体内模型探索伯氏疏螺旋体粘附素的全部功能。对已知粘附素 DbpA、BBK32 和 P66 的重要新见解，并定义了 OspF 亚家族和 OspC 的新粘附功能，之前已证明这对于完全感染性至关重要。组织向性，因此粘附素库的菌株特异性差异可能导致临床表现的相应差异，我们发现 BBK32 和 P66 具有作用。在血管粘附和关节侵袭中，它们介导的与血管内皮的相互作用可能反映了类似于淋巴细胞迁移的连续活动，我们发现伯氏疏螺旋体利用多种具有不同活性的粘附素来协商多相和连续的步骤。此外，粘附素子集的序列变异可能会促进不同位点的定植，并导致组织趋向性和疾病的菌株特异性差异。由伯氏疏螺旋体粘附素的复杂成分介导的多种宿主细胞相互作用协调血管附着、侵袭组织和不同组织的长期定植，我们将利用伯氏疏螺旋体遗传系统和多种小鼠感染模型的力量来扩展。并充分表征促进与内皮细胞相互作用的伯氏疏螺旋体粘附素，以确定小鼠组织传播和长期定植所需的粘附素-配体相互作用。这些相互作用在促进附着于血管内皮、跨过该屏障以稳定定植组织所需的多个步骤中的作用。拟议的工作将把复杂的粘附途径组织成介导感染过程中离散步骤的功能组。共同导致小鼠全身性莱姆疏螺旋体病和播散性持续感染。