Assembly of Live Nipah Virus with Complement Factors

活尼帕病毒与补体因子的组装

• 批准号: 8896985
• 负责人: Griffith D. Parks
• 金额: $ 2.13万
• 依托单位: UNIVERSITY OF CENTRAL FLORIDA
• 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 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8896985
• 关键词: Assembly; Live; Nipah; Virus; Complement

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' inhibitor 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 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 protein in evading innate immunity. In Aim 1, we will use biochemical approaches to test the hypothesis that functional human Factor I interacts specifically with the NiV F protein. Work in Aim 2 will involve studies with live NiV infection under 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 I, 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.

补体系统是大多数动物病毒遇到的先天免疫反应的关键部分 在自然感染期间。虽然很明显补体 (C') 是中和 一些 RNA 病毒，关于 C' 如何调节副粘病毒的机制细节知之甚少 感染。在这里，我们寻求填补补体（C'）与新兴的相互作用的理解空白。 高致病性副粘病毒尼帕病毒（NiV）。 该项目源于我们最近发表的发现：1）补体在体外被激活 含有 NiV F 和 G 糖蛋白的假型病毒，但重要的是，与我们发现的任何其他副粘病毒不同 到目前为止已经测试过这不会导致中和。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，但与 HN 蛋白无关，并且 3) 因子 I 相关 NiV 假型可以通过裂解成 iC3b 来灭活 C3b。第二个和第三个的新颖之处 研究结果是，到目前为止，还没有其他病原体能够招募因子 I 作为逃避机制的报道。 补充。此外，支持我们的假设将显示副粘病毒 F 的新功能 逃避先天免疫的蛋白质。 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 的假设 与 NiV F 蛋白特异性相互作用。目标 2 的工作将涉及在以下条件下对活 NiV 感染进行研究 生物安全 4 级 (BSL4) 条件。我们将确定活 NiV 在体外激活 C' 的程度，并 C' 中和 NiV 传染性的能力。除了招募可溶性因子 I 之外，我们假设 NiV 还捕获 C' 的细胞表面抑制剂，例如 CD46 和 CD55。这将使用实时测试 NiV 感染表达不同水平抑制剂的组织培养细胞。 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活 NiV 在 BSL-4 条件下，并为 C' 逃避的新机制获得进一步的支持数据。两者都是 采取必要的步骤，为活病毒的更详细的机制研究奠定安全的基础 进入动物模型实验。