Determinants of Pathogenic Hantavirus Attachment

描述(申请人提供)：汉坦病毒感染内皮细胞(ECs)并导致两种基于血管通透性的疾病：肾综合征出血热(HFRS)和汉坦病毒肺综合征(HPS)。致病性汉坦病毒结合在弯曲、失活的1v23整合素顶端的53个残基PSI结构域，并失调1v23整合素功能(33，73)。1v23功能缺失是血管通透性和出血性疾病的已知原因，只有致病性汉坦病毒才能结合1v23。汉坦病毒与23的结合是RGD非依赖的，但尚未发现结合所需的汉坦病毒附着蛋白和结构域。我们鉴定了致病性和非致病性汉坦病毒表面蛋白的两个差异，这两个差异与1v23整合素的使用有关。在这里，我们将研究致病汉坦病毒与23整合素PSI结构域结合所需的汉坦病毒表面糖蛋白的结构域和残基。汉坦病毒表面蛋白是以多聚蛋白的形式合成的，它被共翻译为Gn和GC片段，并被运送到发生汉坦病毒萌发的顺式高尔基体。到目前为止，所有测试的致病性汉坦病毒都使用1v23整合素进入病毒，而非致病性汉坦病毒使用离散的1521整合素。这些发现表明，汉坦病毒Gn或GC表面蛋白的独特变化可能区分致病性和非致病性汉坦病毒的病毒附着。我们发现了2个非致病性汉坦病毒特有的GC残基变化，这些变化在高度分化的致病汉坦病毒中不存在。我们对致病汉坦病毒与23个整合素PSI结构域结合的研究为确定汉坦病毒介导结合的蛋白质、结构域和残基提供了基础。拟议的研究可能为汉坦病毒疗法的开发确定病毒特异性靶点，针对病毒附着域的疫苗和抗体可能具有直接治疗应用。目的：在这项建议中，我们将定义致病汉坦病毒与23个整合素PSI结构域结合所需的结构域和残基，并确定这些结构域是否能激发中和抗体反应。具体目的：1)分析PSI结构域与致病汉坦病毒表面蛋白的结合2)GnGc伪型病毒将被用来定义1v23结合的要求3)PSI结合所需的GnGc多肽抗体将被评估其抑制汉坦病毒感染的能力和PSI结构域结合公共卫生的相关性：致病汉坦病毒与23受体上称为PSI结构域的小蛋白结构域结合并靶向负责与23受体结合的病毒蛋白是抑制汉坦病毒感染性的可行方法，并可能成为调节致病性汉坦病毒疾病的抗病毒治疗方法。在这里，我们建议定义负责将病毒附着到23PSI结构域的病毒蛋白成分。将分析小段汉坦病毒表面蛋白结合1v23 PSI结构域、阻断汉坦病毒感染、诱导结合汉坦病毒的抗体以及阻止汉坦病毒与细胞1v23受体相互作用的能力。

DESCRIPTION (provided by applicant): Hantaviruses infect endothelial cells (ECs) and cause 2 vascular permeability-based diseases: Hemorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus Pulmonary Syndrome (HPS). Pathogenic hantaviruses bind to a 53 residue PSI domain present at the apex of bent, inactive, 1v23 integrins and dysregulate 1v23 integrin function (33, 73). The absence of 1v23 function is a known cause of vascular permeability and hemorrhagic disease, and only pathogenic hantaviruses bind 1v23. Hantavirus binding to 23 is RGD independent, however hantavirus attachment proteins and domains required for binding have not been discovered. We have identified 2 differences between surface proteins of pathogenic and non-pathogenic hantaviruses which correlate with 1v23 integrin usage. Here we will investigate the domains and residues of hantavirus surface glycoproteins required for pathogenic hantavirus binding to the 23 integrin PSI domain. Hantavirus surface proteins are synthesized as a polyprotein that is co-translationally cleaved into Gn and Gc fragments and trafficked to the cis-Golgi where hantavirus budding occurs. To date all pathogenic hantaviruses tested use 1v23 integrins for viral entry while non-pathogenic hantaviruses use discrete 1521 integrins. These findings suggest that unique changes in hantavirus Gn or Gc surface proteins are likely to differentiate viral attachment of pathogenic and non-pathogenic hantaviruses. We identified 2 Gc residue changes that are unique to non-pathogenic hantaviruses and not present in highly divergent pathogenic hantaviruses. Our studies of pathogenic hantavirus binding to 23 integrin PSI domains provide a basis for defining hantavirus proteins, domains and residues that mediate attachment. Proposed studies are likely to identify virus specific targets for the development of hantavirus therapeutics and vaccines and antibodies to viral attachment domains are likely to have direct therapeutic application. Objective: In this proposal we will define the domains and residues of pathogenic hantaviruses required for binding to 23 intergrin PSI domains and determine whether these domains elicit neutralizing antibody responses. Specific Aims: 1) Analyze PSI Domain Binding to Pathogenic Hantavirus Surface Proteins 2) GnGc Pseudotyped Virus Will be used to Define Requirements for 1v23 Binding 3) Antibodies to GnGc Peptides Required for PSI Binding will be evaluated for their ability to Inhibit Hantavirus Infection and PSI Domain Binding PUBLIC HEALTH RELEVANCE: Pathogenic hantaviruses bind to a small protein domain on 23 receptors called the PSI domain and targeting the viral protein that is responsible for binding to the 23 receptor is a viable means of inhibiting hantavirus infectivity and may be an antiviral therapeutic approach for regulating pathogenic hantavirus disease. Here we propose to define the viral protein components that are responsible for attaching the virus to the 23 PSI domain. Small pieces of hantavirus surface proteins will be analyzed for their ability to bind 1v23 PSI domains, block hantavirus infection, elicit antibodies that bind hantaviruses and prevent hantavirus interactions with cellular 1v23 receptors.