HMPV Fusion protein-host cell interactions

HMPV 融合蛋白-宿主细胞相互作用

• 批准号: 7483270
• 负责人: Rebecca E. Dutch
• 金额: $ 21.56万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7483270
• 关键词: Acute; Address; Age; Animal Model; Binding; Biological Assay; Carbohydrates; Cell Communication; Cell Line; Cell Surface Proteins; Cell fusion; Cell membrane; Cell surface; Cells; Cellular Structures; Chemicals; Child; Chimeric Proteins; Cultured Cells; Enzymes; Family; Future; GTP-Binding Proteins; Genes; Glycoproteins; Glycosaminoglycans; Goals; Hamsters; Human; Human Metapneumovirus; Human respiratory syncytial virus; Individual; Infant; Infection; Infectious Agent; Lead; Location; Lung diseases; Mediating; Membrane Fusion; Metapneumovirus; Modification; Paramyxovirus; Paramyxovirus Fusion Protein; Process; Production; Proteins; Proteoglycan; Proteolytic Processing; Reagent; Recombinants; Reporter Genes; Reporting; Research; Respiratory Tract Diseases; Respiratory syncytial virus; Sampling; Sequence Analysis; Staging; Symptoms; Trypsin; Viral; Viral Proteins; Virus; attachment protein G; cell type; crosslink; experience; inhibitor/antagonist; nonhuman primate; pathogen; protein function; receptor; treatment effect

DESCRIPTION (provided by applicant): Human metapneumovirus (HMPV) is a recently identified paramyxovirus associated with severe respiratory disease, particularly in infants, with symptoms that closely resemble those seen with respiratory syncytial virus. We have established efficient assays for the study of membrane fusion promoted by the HMPV fusion (F) glycoprotein. Interestingly, HMPV F protein-mediated cell-cell fusion only occurs when transfected cells are both treated with trypsin (to proteolytically process the HMPV F protein) and exposed to low pH. As previously studied paramyxovirus F proteins promote fusion at neutral pH at the plasma membrane, the triggering of HMPV F protein fusion activity by low pH suggests that this protein functions in a manner unique among the paramyxoviruses. Our results also demonstrate that HMPV F is competent to promote fusion in the absence of the attachment (G) protein, consistent with reports that recombinant HMPV viruses lacking the HMPV G protein replicate efficiently both in cell culture and in hamster and non-human primate animal model. Our long-term goal is to understand the attachment and entry of paramyxoviruses. Our specific hypothesis is that HMPV F interacts with one or more defined cellular receptors, and that this interaction is necessary to prime the F protein for low-pH induced promotion of membrane fusion. To address this hypothesis we will pursue three research aims. First, we will utilize our recently developed, efficient reporter gene assay to systematically define the target cell components required for HMPV F protein-promoted membrane fusion. Second, we will analyze the effect of treatments to the HMPV F protein on promotion of membrane fusion, including effects of prior low pH treatment, proteolytic processing of the F protein or addition of soluble glycosaminoglycans. Finally, we will utilize a soluble form of the HMPV F protein to analyze binding and identify the specific cellular receptor(s) for HMPV F. Accomplishing these goals will provide crucial information on the cellular components that interact with the HMPV F protein, and may well lead to identification of the first receptor for a paramyxovirus fusion protein. In addition, these studies will further clarify the mechanism by which the HMPV F protein promotes critical early steps in infection, and set the stage for future analysis of inhibitors of this important viral protein. Human metapneumovirus (HMPV) is a recently identified human pathogen responsible for significant levels of severe respiratory disease, particularly in infants. This research will address significant questions concerning the cellular factors which interact with the HMPV fusion protein to facilitate attachment of the virus and entry into cells.

描述（由申请人提供）：人类元瘤病毒（HMPV）是最近发现的与严重呼吸系统疾病相关的帕托马病毒，尤其是在婴儿中，症状与呼吸道合胞病毒的症状非常相似。我们已经建立了有效的测定法，以研究由HMPV融合（F）糖蛋白促进的膜融合。有趣的是，仅当转染的细胞都用胰蛋白酶处理（以蛋白水解处理HMPV F蛋白）并暴露于低pH值时，HMPV F蛋白介导的细胞融合才会发生。正如先前研究的丙糖病毒F蛋白在质膜处促进中性pH值的融合，低pH值触发HMPV F蛋白融合活性的触发表明，该蛋白质以帕托马伏病毒在特殊的方式起作用。我们的结果还表明，HMPV F在没有附着蛋白（G）蛋白质的情况下有能力促进融合，这与重组HMPV病毒缺乏HMPV G蛋白在细胞培养和仓鼠和非人类灵长类动物模型中有效复制的报道有效地复制了HMPV病毒。我们的长期目标是了解Paramyxovires的依恋和进入。我们的特定假设是HMPV F与一个或多个定义的细胞受体相互作用，并且这种相互作用对于低pH诱导促进膜融合的F蛋白是必不可少的。为了解决这一假设，我们将追求三个研究目标。首先，我们将利用我们最近开发的有效的记者基因测定法来系统地定义HMPV F蛋白促进的膜融合所需的靶细胞成分。其次，我们将分析治疗对HMPV F蛋白促进膜融合的影响，包括先前低pH处理的影响，F蛋白的蛋白水解加工或添加可溶性糖胺聚糖。最后，我们将利用HMPV F蛋白的可溶形式来分析结合并确定HMPV F的特定细胞受体。此外，这些研究将进一步阐明HMPV F蛋白促进感染中关键早期步骤的机制，并为将来分析这种重要病毒蛋白的抑制剂奠定了基础。人类元小病毒（HMPV）是最近确定的人类病原体，导致严重呼吸道疾病，特别是在婴儿中。这项研究将解决有关与HMPV融合蛋白相互作用的细胞因子，以促进病毒的附着并进入细胞。