Cellular responses to human metapneumovirus infection

描述(申请人提供)：我的长期职业目标是研究导致呼吸道病毒感染发病的病毒和宿主特异性机制，以开发新的治疗干预措施，以及可行的候选疫苗。K22奖将帮助我提供作为一名独立调查员建立职业生涯所需的初步支持。人偏肺病毒(HMPV)是新近发现的一种属于副粘病毒科的呼吸道病毒。它是儿童呼吸道感染的主要原因。关于hMPV感染的发病机制，目前知之甚少。这项建议的目的是利用分子病毒学、细胞生物学和蛋白质化学技术相结合的方法来研究宿主细胞对hMPV感染的反应。我最近发现，RNA解旋酶-MAVS信号通路在hMPV诱导的免疫和炎症基因的表达中发挥着重要作用，包括I型干扰素和趋化因子，这些基因是通过激活核因子？B(核因子？B)和干扰素调节因子(IRF)转录因子。初步研究表明，hMPV糖蛋白G和小分子疏水蛋白SH可能通过干扰依赖于RIG-I和PKA的信号转导来调节hMPV诱导的细胞反应。本研究的目的是确定宿主信号分子与病毒蛋白之间的分子相互作用，并将通过以下具体目标来实现：目的1.明确G抑制RIG-L介导的信号转导的分子机制。为此，我们将研究G蛋白的表达是否通过破坏RIG-I与其下游接头MAV的联系和/或通过从RIG-I中分离病毒RNA来干扰RIG-I依赖的信号转导。我们还将确定哪些G残基对于调节hMPV诱导的细胞信号是重要的。目的2.明确SH抑制核因子-β活化的分子机制。为此，我们将首先确定SH抑制核因子-β磷酸化的机制。然后我们将映射对其抑制活性至关重要的SH残基(S)。相关性(见说明)：在拟议的研究完成后，我们将获得关于hMPV诱导的细胞信号机制的新的关键信息，这可能使我们能够特异性地调节病毒诱导的基因表达，从而抑制病毒和先天免疫/炎症反应。这些研究的结果将有助于未来安全有效的hMPV候选疫苗的开发。

DESCRIPTION (provided by applicant): My long-term career goal is to investigate viral- and host-specific mechanisms that contribute to the pathogenesis of respiratory viral infections, in order to develop novel therapeutic intervention, as well as viable vaccine candidates. The K22 award will help me by providing the initial support necessary to establish a career as an independent investigator. Human metapneumovirus (hMPV) is a recently identified respiratory virus belonging to the Paramyxoviridae family. It is a leading cause of respiratory infections in children. Little information is available regarding the pathogenesis of hMPV infection. The aim of this proposal is to investigate host cellular responses to hMPV infection using a combination of molecular virology, cellular biology and protein chemistry techniques. I have recently shown that the RNA helicases-MAVS signaling pathway plays a significant role in hMPV-induced expression of immune and inflammatory genes, including type I interferon and chemokines, which are regulated through the activation of Nuclear Factor-? B (NF-?B) and Interferon Regulatory Factors (IRF) transcription factors. Preliminary studies demonstrated that hMPV glycoprotein G and small hydrophobic protein SH modulate hMPV-induced cellular responses by likely disrupting RIG-I- and PKA-dependent signaling. The goal of this proposal is to identify molecular interaction between host signaling molecules and viral proteins and will be accomplished through the following specific aims: Aim 1. To define the molecular mechanism whereby G inhibits RIG-l-mediated signaling. In this aim, we will investigate whether G protein expression interferes with RIG-I dependent signaling by disrupting the association of RIG-I with its downstream adaptor MAVS and/or by sequestering viral RNA from RIG-I. We will also identify which residues of G are important for modulating hMPV-induced cellular signaling. Aim 2. To define the molecular mechanism whereby SH inhibits NF-?B activation. In this aim, we will first determine the mechanism by which SH inhibits NF-?B phosphorylation. We will then map SH residue(s) critical for its inhibitory activity. RELEVANCE (See instructions): Upon completion of the proposed studies, we will obtain new critical information on the mechanisms of hMPV-induced cellular signaling, which may allow us to specifically modulate viral-induced gene expression and therefore antiviral and innate immune/inflammatory responses. The results obtained from these studies will be instrumental for the development of future hMPV vaccine candidates which are safe and effective.