Assembly of Live Nipah Virus with Complement Factors

活尼帕病毒与补体因子的组装

• 批准号: 8358727
• 负责人: Griffith D. Parks
• 金额: $ 8.12万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8358727
• 关键词: Animal Model; Animal Viruses; Binding; Biochemical; C3bi; CD46 Antigen; Cell surface; Cellular Membrane; Cleaved cell; Complement; Complement 3b; Complement Inactivators; Complement component C1; Data; Face; Fibrinogen; Foundations; HN Protein; Hendra Virus; Human; Immune response; Immune system; In Vitro; Infection; Life; Mediating; Membrane; Modeling; Natural Immunity; Nipah Virus; Outcome; Paramyxovirus; Pathogenesis; Pathway interactions; Peptide Hydrolases; Pilot Projects; Positioning Attribute; Process; Proteins; Publishing; RNA Viruses; Recruitment Activity; Refractory; Reporting; Role; Secure; Solid; Specificity; Testing; Therapeutic; Virion; Virus; Virus Diseases; Work; biosafety level 4 facility; complement pathway; complement system; glycoprotein G; inhibitor/antagonist; insight; interest; novel; particle; pathogen; research study; response; tissue/cell culture; vaccine development; virus pathogenesis

DESCRIPTION (provided by applicant): The complement system is a critical part of innate immune responses that most animal viruses encounter during natural infections. While it is clear that complement (C') is an important factor in neutralization of some RNA viruses, very few mechanistic details are known about how C' regulates paramyxovirus infections. Here, we seek to fill gaps in understanding of interactions of complement (C') with the emerging highly pathogenic paramyxovirus Nipah virus (NiV). This project emerged from our recent published finding that: 1) complement is activated in vitro by pseudotypes containing the NiV F and G glycoproteins, but importantly, unlike any other paramyxovirus we have tested so far this does not result in neutralization. Our preliminary data also demonstrate that: 2) the cellular C' inhibior Factor I protease associates with the NiV F but not HN protein and 3) Factor I associated with NiV pseudotypes can inactivate C3b by cleavage into iC3b. The novelty of the second and third U findings is that no other pathogen has been reported so far to recruit Factor I as a mechanism to evade complement. In addition, support for our hypothesis would show a new function for the paramyxovirus F U U protein in evading innate immunity. U In Aim 1, we will use biochemical approaches to test the hypothesis that functional human Factor I U U interacts specifically with the NiV F protein. Work in Aim 2 will involve studies with live NiV infection under U U Biosafety Level 4 (BSL4) conditions. We will determine the extent to which live NiV activates C' in vitro and the capacity of C' to neutralize NiV infectivity. In addition to recruitment of soluble Factor , we hypothesize that NiV also captures cell surface inhibitors of C' such as CD46 and CD55. This will be tested using live NiV infection of tissue culture cells that express varying levels of inhibitors. This pilot project seeks to extend our novel findings from studies with NiV pseudotypes into live NiV under BSL-4 conditions, and to gain further supporting data for a novel mechanism of C' evasion. Both are necessary steps to establish a secure foundation for more mechanistic detailed studies with live virus and into experiments in animal models. PUBLIC HEALTH RELEVANCE: There is intense interest in mechanisms that modulate the interplay between viruses and the host innate immune system. The role of complement in neutralizing emerging paramyxoviruses such as Nipah virus and how these viruses counteract complement pathways are unknown. To our knowledge, our novel finding on how Nipah virus evades neutralization has not been described for any other pathogen. Insights into inhibition of complement will have implications for virus pathogenesis and rational approaches to vaccine development.

描述（由申请人提供）：补体系统是大多数动物病毒在自然感染过程中遇到的先天免疫反应的关键部分。虽然很明显补体 (C') 是中和某些 RNA 病毒的重要因素，但关于 C' 如何调节副粘病毒感染的机制细节却知之甚少。在这里，我们试图填补补体（C'）与新兴高致病性副粘病毒尼帕病毒（NiV）相互作用的理解空白。该项目源于我们最近发表的发现：1）补体在体外被含有 NiV F 和 G 糖蛋白的假型激活，但重要的是，与我们迄今为止测试的任何其他副粘病毒不同，这不会导致中和。我们的初步数据还表明：2) 细胞 C' 抑制剂因子 I 蛋白酶与 NiV F 相关，但不与 HN 蛋白相关；3) 与 NiV 假型相关的因子 I 可以通过裂解成 iC3b 使 C3b 失活。第二个和第三个 U 研究结果的新颖之处在于，迄今为止尚未有其他病原体报道可招募 I 因子作为逃避补体的机制。此外，对我们假设的支持将显示副粘病毒 F U U 蛋白在逃避先天免疫方面的新功能。 U 在目标 1 中，我们将使用生化方法来检验功能性人类因子 I U U 与 NiV F 蛋白特异性相互作用的假设。目标 2 的工作将涉及在 U U 生物安全级别 4 (BSL4) 条件下对活 NiV 感染进行研究。我们将确定活 NiV 在体外激活 C' 的程度以及 C' 中和 NiV 感染性的能力。除了招募可溶性因子外，我们假设 NiV 还捕获 C' 的细胞表面抑制剂，例如 CD46 和 CD55。这将使用表达不同水平的组织培养细胞的活 NiV 感染进行测试 抑制剂。该试点项目旨在将我们从 NiV 假型研究中获得的新发现扩展到 BSL-4 条件下的活 NiV 中，并为 C' 逃避的新机制获得进一步的支持数据。两者都是为活病毒的更详细机械研究和动物模型实验奠定安全基础的必要步骤。 公共卫生相关性：人们对调节病毒与宿主先天免疫系统之间相互作用的机制非常感兴趣。补体在中和新出现的副粘病毒（如尼帕病毒）中的作用以及这些病毒如何对抗补体途径尚不清楚。据我们所知，我们关于尼帕病毒如何逃避中和的新发现尚未在任何其他病原体中得到描述。对补体抑制的深入了解将对病毒发病机制和疫苗开发的合理方法产生影响。