Complement-mediated Neutralization of Mumps Virus and SV5

描述(由申请人提供)：这项建议是基于我们实验室的两个引人注目的发现。首先，补体中和了与猴病毒5(SV5)和流行性腮腺炎病毒(MUV)密切相关的副粘病毒，但通过不同的机制，形成大量的SV5聚集体和补体介导的MUV颗粒的裂解。其次，我们的微阵列数据表明，感染非细胞病变的WTSV5导致宿主细胞补体调节水平升高，这些病毒感染的细胞不被补体裂解。我们这个项目的长期目标是了解决定副粘病毒与补体相互作用结果的细胞和病毒因素。短期目标是1)利用一种新的实验系统来识别决定补体中和程度和途径的病毒信号，以及2)确定SV5诱导的补体调节因子在防止病毒感染细胞裂解中的作用。我们应用程序的一个创新方面是使用SV5和Muv病毒样颗粒(VLP)来分析病毒：补体相互作用。这是一个强大而灵活的系统，因为当这些改变在骨骼感染性病毒的背景下是不被容忍的时，可以产生在病毒成分上不同的新型VLP。在目标1中，我们将确定补体与SV5和Muv病毒样颗粒(VLP)相互作用所涉及的细胞途径和病毒决定因素。补体途径和补体激活的病毒决定因素将通过使用病毒糖蛋白HN、F和SH含量不同的VLP来识别。在目标2中，我们将验证这样的假设，即SV5感染的上皮细胞由于宿主细胞补体调节因子的上调而对补体介导的裂解具有抵抗力。人们对确定调节病毒和宿主天然免疫系统之间相互作用的机制非常感兴趣，但补体在中和副粘病毒中的作用还不完全清楚。我们的研究对于理解补体介导的病毒中和、副粘病毒(如MUV)在人类群体中的重新出现和持续感染具有重要意义，以及为新的治疗应用开发新信息的巨大潜力。与公共卫生相关：人们对确定调节病毒和宿主天然免疫系统之间相互作用的机制非常感兴趣，但补体在中和副粘病毒中的作用尚未完全了解。我们的工作将对控制MUV等病毒产生重要影响，尽管接种了广泛的疫苗，但MIV病毒已经重新出现。此外，我们在病毒诱导的补体抑制方面的工作也暗示了病毒建立难以被宿主免疫系统识别的持续性感染的机制。

DESCRIPTION (provided by applicant): This proposal is based on two remarkable findings from our lab. First, complement neutralizes the closely related paramyxoviruses Simian Virus 5 (SV5) and Mumps Virus (MuV), but by distinct mechanisms involving formation of massive SV5 aggregates versus complement mediated lysis of MuV particles. Secondly, our microarray data indicate that infection with the noncytopathic WT SV5 results in elevated levels of host cell regulators of complement and these virus-infected cells are not lysed by complement. Our long term goal of this project is to understand the cellular and viral factors that dictate the outcome of interactions of paramyxoviruses with complement. The short term goals are to 1) utilize a novel experimental system to identify viral signals that dictate the extent and pathway of complement neutralization and to 2) define the role of SV5-induced regulators of complement in preventing lysis of virus infected cells. An innovative aspect of our application is the use of SV5 and MuV virus-like particles (VLP) to analyze virus:complement interactions. This is a powerful and flexible system, in that novel VLPs that differ in viral components can be produced when these alterations would otherwise not be tolerated in the context of a bone fide infectious virus. In Aim 1, we will identify the cellular pathways and viral determinants involved in interactions of complement with SV5 and MuV virus-like particles (VLPs). The complement pathways and the viral determinants of complement activation will be identified through the use of VLPs that differ in their content of viral glycoproteins HN, F and SH. In Aim 2, we will test the hypothesis that SV5-infected epithelial cells are resistant to complement-mediate lysis due to upregulation of host cell regulators of complement. There is intense interest in defining mechanisms that modulate the interplay between viruses and the host innate immune system, but the role of complement in neutralization of paramyxoviruses is not completely understood. Our studies have important implications for understanding complement-mediated neutralization of viruses, the re-emergence in the human population of paramyxoviruses such MuV, and persistent infections, as well as great potential for exploiting the new information for novel therapeutic applications. PUBLIC HEALTH RELEVANCE: There is intense interest in defining mechanisms that modulate the interplay between viruses and the host innate immune system, but the role of complement in neutralization of paramyxoviruses is not completely understood. Our work will have important implications for control of viruses such as MuV, which has re-emerged despite wide-spread vaccination. In addition, our work with virus-induced inhibition of complement has implication for mechanisms by which viruses establish persistent infections that are refractory to recognition by host immune systems.