Molecular and cellular aspects of the life cycle of multipartite viruses: nanoviruses

多部分病毒生命周期的分子和细胞方面：纳米病毒

• 批准号: 406590940
• 负责人: Dr. Björn Krenz
• 金额: --
• 依托单位: Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/406590940?language=en
• 关键词: Molecular; cellular; aspects; life; cycle

Emerging plant viruses are a threat worldwide. Studying their life cycles in details is a prerequisite to reveal alternative control strategies. We will target the family Nanoviridae for both practical and fundamental reasons: i) it represents a huge threat for Musaceae crop (genus Babuvirus) and for legumes (genus Nanovirus), and ii) it has adopted the enigmatic “multipartite” organization, with its genome composed of several nucleic acid segments each encapsidated individually. Nanoviruses being multipartite viruses with the highest number of genome segments described thus far, they are perfect models to investigate processes that might be specific to this viral genomic architecture most frequently adopted by plant viruses. In particular, how such viruses can efficiently infect a high proportion of cells/hosts with at least one copy of each of their numerous genome segments remains elusive. It is deemed impossible in the literature that actually questions the conceptual frame with which we try to comprehend the multipartite viral systems. Consistently, we recently showed that a nanovirus do not function in a way that fits the current concepts in virology. The virus spreads distinct genome segments in distinct individual cells of the host. These segments functionally complement across cells and thereby define a pluricellular way of life. This unprecedented discovery in virology now requires in depth investigation to decipher the mechanisms allowing such a surprising viral lifestyle. More specifically the Krenz group analyzes the viral proteins role during virus-host interactions, while the Blanc group studies the within-host viral population dynamics and the virus-vector interactions during plant-to-plant transmission. Through this project, we will join forces to study the full lifecycle. We propose to decipher the biochemical and biological properties of various nanoviral gene products interacting with host plants and aphid vectors. We aim to understand how distinct viral genome segments initially expressed in distinct plant cells actually function, how they can communicate and complement at a distance and at a supra-cellular scale. We will analyze the properties of the viral gene products with a focus on those with yet unknown function, and on properties that could be involved in trafficking among cells for complementation. Likewise, we will strive to understand how virus particles successfully travel through the body of their aphid vectors, ensuring that all segments are acquired, transported across aphid’s cell barriers, and inoculated together. Thus, beyond the urgent need to better understand the biology of nanoviruses, an emerging threat worldwide, another ambitious goal of this project is to decipher the means by which a multipartite virus can sustain a pluricellular lifestyle, and thereby definitely coin this discovery as a new research horizon in plant virology and beyond.

新出现的植物病毒是世界范围内的威胁。详细研究它们的生命周期是揭示替代控制策略的前提。我们将针对纳米病毒科有实际和根本的原因：1)它对芭蕉科作物(巴布亚病毒属)和豆科植物(纳米病毒属)构成了巨大的威胁；2)它采用了神秘的“多部分”组织，其基因组由几个核酸片段组成，每个片段都被单独包裹。纳米病毒是迄今为止描述的基因组片段数量最多的多部分病毒，它们是研究植物病毒最常采用的这种病毒基因组结构特有的过程的完美模型。特别是，这种病毒如何能够有效地感染高比例的细胞/宿主，其众多基因组片段中的每一个至少有一个副本仍然难以捉摸。在实际质疑我们试图理解多方病毒系统的概念框架的文献中，这被认为是不可能的。我们最近一致地证明，纳米病毒的功能并不符合病毒学中当前的概念。该病毒在宿主的不同个体细胞中传播不同的基因组片段。这些片段在功能上是跨细胞的互补，从而定义了一种多细胞的生活方式。病毒学上这一史无前例的发现现在需要深入研究，以破译导致这种令人惊讶的病毒生活方式的机制。更具体地说，Krenz小组分析病毒与宿主相互作用过程中的病毒蛋白质作用，而Blanc小组研究宿主内病毒种群动态以及植物间传播过程中病毒与病媒的相互作用。通过这个项目，我们将联合起来研究全生命周期。我们建议破译各种纳米病毒基因产物与寄主植物和蚜虫载体相互作用的生化和生物学特性。我们的目标是了解最初在不同植物细胞中表达的不同病毒基因组片段实际上是如何发挥作用的，它们如何在远距离和超细胞水平上进行沟通和互补。我们将分析病毒基因产物的特性，重点放在那些功能尚不清楚的产品上，以及可能参与细胞间交易以进行互补的特性。同样，我们将努力了解病毒颗粒是如何成功地通过其蚜虫载体的体内传播的，确保所有片段都被获取，运输穿过蚜虫的细胞屏障，并一起接种。因此，除了迫切需要更好地了解纳米病毒的生物学，这是一种世界性的新兴威胁之外，该项目的另一个雄心勃勃的目标是破译多部分病毒维持多细胞生活方式的方法，从而明确地将这一发现作为植物病毒学和其他领域的新研究领域。