Structural controls of functional receptor and antibody binding to viral capsids

功能受体和抗体与病毒衣壳结合的结构控制

• 批准号: 8040822
• 负责人: Colin R. Parrish
• 金额: $ 39.97万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8040822
• 关键词: Academic Medical Centers; Address; Affect; Affinity; Amino Acids; Animal Viruses; Animals; Antibodies; Area; Binding; Binding Sites; Biological Assay; Canine Parvovirus; Canis familiaris; Capsid; Capsid Proteins; Cell physiology; Cells; Cleaved cell; Complex; Cryoelectron Microscopy; DNA; Disease; Engineering; Environment; Epidemic; Face; Family Felidae; Fc Receptor; Feline Parvovirus; Feline panleukopenia virus; Felis catus; Genetic; Genome; Growth; Human; Human Parvovirus B19; Human Virus; Hydrogen Bonding; Infection; Infection Control; Ions; Laboratories; Lead; Life Cycle Stages; Ligand Binding; Maps; Modeling; Modification; Mutation; Organized by Structure Protein; Outcome; Parvovirus; Pennsylvania; Peptide Hydrolases; Peptides; Polysaccharides; Positioning Attribute; Property; Proteolysis; Receptor Cell; Resolution; Role; Series; Site; Source; Structure; Surface; Tertiary Protein Structure; Testing; Therapeutic; Transferrin Receptor; Universities; Vaccines; Variant; Viral; Viral Physiology; Viral Proteins; Viral Structural Proteins; Virus; Virus Diseases; flexibility; human TFRC protein; mutant; pandemic disease; pathogen; receptor; receptor binding; skills; success; viral DNA; virus host interaction

DESCRIPTION (provided by applicant): Here we seek to understand how structural flexibility and variation in parvoviral capsids control their ability to bind receptors leading to cell infection and also to variation in host range, and also how capsid structures control antibody binding and neutralization. Those areas of study are significant because they are features of all animal and human viruses. While parvovirus capsids appear structurally simple, they are clearly sophisticated biomolecular machines that carry out many functions using variants of a single capsid protein, and the features controlling many functions have now been mapped to specific mutations and capsid structures, presenting an opportunity to gain a complete understanding of how virus-host interactions occur in fine detail. Parvoviruses include the B19 virus, human bocavirus, and Parv4, all of which cause disease in humans. Here we use feline and canine parvoviruses as models to build on our previous studies showing that cell infection and animal host ranges are controlled by specific interactions of the capsids with the transferrin receptors type-1 (TfR) of different hosts. There are also distinct outcomes for viral infection of antibody binding, depending on the binding site and angle of attachment. The three overlapping areas to be investigated in this project are: 1. Define the functional effects of variant and flexible structures of the parvovirus capsids. There is both flexibility and structural variation in the viral capsids which we will further characterize in detail. Some of that variation is asymmetric, only occurring in a small proportion of the capsid subunits, while other variation occurs in most viral sites. Many of those sites are known to affect viral functions. 2. Characterize how different interactions between parvovirus capsids and TfR or other receptors control infection. Capsid binding to different TfRs is controlled by the protein structure, and flexibility, and potentially by protease cleavages. To define the functional TfR binding to the capsids we will use a variety of approaches, including cryoEM analysis and analysis of capsid mutants affecting binding. To define the TfR interaction we will use receptors containing amino acid changes or added glycans within the interaction sites. 3. Use antibody binding to capsids to define their structures, and also to explain the mechanisms of antibody neutralization. We have many antibodies that bind the capsid structures. Some neutralize as Fabs, and others do not. We will use those antibodies as probes for structural variation in the capsids. The antibodies and their domains will be used in competition assays to further define the binding of different TfRs to the capsids, and to detect cleaved subunits or other capsid modifications. Antibodies with altered binding affinities, different attachment sites, or different angles of attachment would be tested for effects on the virus functions involved in cell infection. PUBLIC HEALTH RELEVANCE: This project addresses several issues of central importance to the success of all viruses infecting humans and other animals. Those include: how viral proteins vary in structure over their life cycles, the mechanisms of binding to different receptors, how differences in viral structural proteins can control their host ranges, the processes of cell infection, and how antibody binding can neutralize the virus in some cases but not others. These studies will show how altered receptor binding can lead to the emergence of new epidemic or pandemic viruses, and will also reveal new ways to make more effective vaccines or therapeutics. The specific model viruses being examined infect animals, but they are similar to a variety of important viruses of humans. The small sizes and simple genetic and capsid structures of the parvoviruses make them excellent models for defining the most basic aspects of the viral-host interaction, and the results and broad conclusions will be directly relevant to the better understanding of many different viruses of humans.

描述（由申请人提供）：在这里，我们试图了解山视角衣壳中的结构柔韧性和变化如何控制其结合受体导致细胞感染以及宿主范围变化的能力，以及帽结构如何控制抗体结合和中和化。这些研究领域很重要，因为它们是所有动物和人类病毒的特征。虽然细小病毒的衣壳在结构上看起来很简单，但它们显然是复杂的生物分子机器，使用单个衣壳蛋白的变体执行许多功能，并且控制了许多功能的功能已映射到特定的突变和capsID结构，并提供了一种机会，以获得对病毒互动的完整理解。细节病毒包括B19病毒，人类Bocavirus和Parv4，所有这些都会引起人类疾病。在这里，我们使用猫科和犬斑线病毒作为模型来建立我们以前的研究，表明细胞感染和动物宿主范围受capsids与不同宿主的转铁蛋白受体类型1（TFR）的特定相互作用的控制。抗体结合的病毒感染也有不同的结果，具体取决于结合位点和依恋角。在该项目中要研究的三个重叠区域是：1。定义细小病毒衣壳变体和柔性结构的功能效应。病毒式衣壳的灵活性和结构变化既存在，我们将进一步详细描述。其中一些变异是不对称的，仅发生在一小部分的衣壳亚基中，而其他变化发生在大多数病毒部位。这些站点中的许多位置都会影响病毒功能。 2。表征细小病毒衣壳与TFR之间的不同相互作用或其他受体控制感染。衣壳结合与不同TFR的结合受蛋白质结构和柔韧性的控制，并可能由蛋白酶切割。为了定义与衣壳的功能性TFR结合，我们将使用各种方法，包括冷冻分析和影响结合结合的衣壳突变体的分析。为了定义TFR相互作用，我们将使用含有氨基酸变化的受体或在相互作用位点中添加的聚糖。 3。使用与衣壳结合的抗体来定义其结构，并解释抗体中和的机理。我们有许多结合衣壳结构的抗体。有些人将其作为晶圆厂中和，而另一些则没有。我们将使用这些抗体作为衣壳结构变化的探针。抗体及其结构域将用于竞争测定中，以进一步定义不同TFR与衣壳的结合，并检测裂解的亚基或其他衣壳修饰。将测试具有改变结合亲和力，不同依恋位点或附着角度的抗体，以测试对细胞感染涉及的病毒功能的影响。 公共卫生相关性：该项目解决了所有感染人类和其他动物的病毒成功的核心问题。其中包括：病毒蛋白在生命周期中的结构，与不同受体结合的机制如何变化，病毒结构蛋白的差异如何控制其宿主范围，细胞感染的过程以及抗体结合在某些情况下如何中和该病毒。这些研究将表明受体结合改变如何导致新的流行病或大流行病毒的出现，还将揭示新的方法来制造更有效的疫苗或治疗剂。特定的模型病毒被检查，但它们类似于人类的各种重要病毒。小小的小小的尺寸和简单的遗传和衣壳结构使其成为定义病毒宿主相互作用最基本方面的绝佳模型，结果和广泛的结论将与对许多不同人类病毒的更好理解直接相关。