Determinants of Pathogenic Hantavirus Attachment

描述（由申请人提供）：汉坦病毒感染内皮细胞（ECs）并引起2种血管通透性疾病：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位于弯曲、无活性的1v23整合素顶端的53个残基PSI结构域，并失调1v23整合素的功能（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与1v23结合。汉坦病毒与23的结合与RGD无关，但尚未发现汉坦病毒结合所需的附着蛋白和结构域。我们发现致病性和非致病性汉坦病毒表面蛋白与1v23整合素使用相关的2个差异。在这里，我们将研究致病性汉坦病毒与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。汉坦病毒表面蛋白作为多蛋白合成，共翻译切割成Gn和Gc片段，并转运到汉坦病毒出芽发生的顺式高尔基体。迄今为止，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Gc残基变化是非致病性汉坦病毒所特有的，而不存在于高度分化的致病性汉坦病毒中。我们对致病性汉坦病毒与23个整合素PSI结构域结合的研究为定义介导附着的汉坦病毒蛋白、结构域和残基提供了基础。拟议的研究可能会为开发汉坦病毒疗法确定病毒特异性靶点，而针对病毒附着结构域的疫苗和抗体可能具有直接的治疗应用。目的：在本研究中，我们将确定致病性汉坦病毒与23个intergrin 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会引发中和抗体反应。具体目的：1)分析PSI结构域与致病性汉坦病毒表面蛋白的结合；2)GnGc假型病毒将用于确定1v23结合的要求；3)PSI结合所需的GnGc肽抗体将被评估其抑制汉坦病毒感染的能力和PSI结构域结合的公共卫生相关性。致病性汉坦病毒与23受体上一个称为PSI结构域的小蛋白质结合，并靶向负责与23受体结合的病毒蛋白是抑制汉坦病毒传染性的可行手段，可能是调节致病性汉坦病毒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。汉坦病毒表面蛋白的小片段将被分析其结合1v23 PSI结构域、阻断汉坦病毒感染、引发结合汉坦病毒的抗体和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.