Protecting bees from viruses

蜜蜂对粮食作物授粉和生产蜂蜜等蜂巢产品至关重要。在过去的二十年里，欧洲和北美的蜜蜂数量都在下降。这是由于一些非本地害虫和病原体的入侵，损害蜜蜂，但也由于病毒的流行和毒力的变化，假定是由引入的寄生螨，狄斯瓦螨诱导。由于瓦螨属对化学杀虫剂的广泛耐药性以及市场上可获得的新产品很少，因此对这些病毒没有控制措施。沃尔巴克氏体是一种细胞内细菌，生活在大量昆虫物种的细胞内，包括黄蜂、蜜蜂和少量蜜蜂，甚至一些蜘蛛和蠕虫物种。沃尔巴克氏体在英国很普遍。这种细菌的某些菌株可以使其宿主对某些致病病毒产生抵抗力。研究人员利用这一点与传播登革热，寨卡和基孔肯雅病毒的蚊子一起工作;在实验室和田间试验中，细菌使蚊子对这些病毒具有抵抗力。重要的是，一些能使宿主对病毒产生抵抗力的沃尔巴克氏体菌株似乎并没有对昆虫宿主造成严重的适应性惩罚。我们的核心假设是，基于这些来自其他昆虫物种的明确数据，感染适当的沃尔巴克氏体菌株将使蜜蜂对重要的蜜蜂病毒产生抵抗力;这些病毒与已知被沃尔巴克氏体抑制的病毒有关。我们将在培养的蜜蜂细胞中测试这一假设，这使得比使用蜜蜂更快速地测试沃尔巴克氏体病毒组合。我们还将探讨对微孢子虫寄生虫微孢子虫的影响，因为有一些证据表明沃尔巴克氏体也可以抑制细胞病原体。除了在蜜蜂细胞系中测试沃尔巴克氏体外，我们还可以在实验室笼子里对单个蜜蜂进行直接研究。在蚊子中，成年人可以注射纯化的沃尔巴克氏体菌株，它将通过组织传播，这被称为“短暂”感染。然后可以用病毒攻击这些昆虫，以获得Wolbachia感染影响的指示。成年蜜蜂将在封闭的环境中以同样的方式受到挑战，作为沃尔巴克氏体潜在抗病毒或抗微孢子虫活性的补充方法。我们建议调查使用沃尔巴克氏体抑制正义RNA病毒的可行性，使用蜜蜂细胞系作为概念的初步证明。我们将通过四个相互关联的目标来实现这一目标：目标1：建立细胞培养并建立沃尔巴克氏体感染和沃尔巴克氏体游离衍生物目标2：建立细胞系中的病毒和微孢子虫培养目标3：在沃尔巴克氏体感染和沃尔巴克氏体游离细胞系上测试病原体感染目标4：检测和测试工蜂的瞬时沃尔巴克氏体感染显然需要新的方法来控制蜜蜂中的病毒和细胞病原体。该项目旨在探索基于沃尔巴克氏体的非化学方法的潜力，如果实现，将可能很好地适应增强的，可持续的综合蜜蜂健康计划。如果沃尔巴克氏体能够抑制病毒和/或微孢子虫。在蜜蜂中，这将为控制蜜蜂疾病提供令人兴奋的新方法;该项目将测试这种方法的可行性。沃尔巴克氏体通过雌性生殖系传播，因此沃尔巴克氏体感染的蜂王可以用来产生抗病群体。这种基于沃尔巴克氏体的方法不涉及使用重组DNA方法，并且所产生的菌株不被认为是转基因生物（GMO），与其他一些潜在的病原体抗性遗传方法相比，为任何最终的实地使用提供了更低的障碍。

Honey bees are crucial for pollination of food crops and production of hive products such as honey. In the past two decades, honey bees have suffered from declines across Europe and North America. This is due to a number of incursions of non-native pests and pathogens which damage honey bees, but also due to a change in the prevalence and virulence in viruses posited to be induced by the introduced parasitic mite, Varroa destructor. There are no controls for these viruses and management of Varroa is challenging due to widespread resistance to chemical pesticides and few new products available for this market.Wolbachia are intracellular bacteria which live inside the cells of a large number of insect species, including species of wasps, bees and a small number of honey bees, and even some spider and worm species. Wolbachia are widespread in the UK. Some strains of this bacteria can make their host resistant to certain pathogenic viruses. This has been exploited by researchers working with the mosquitoes that transmit Dengue, Zika and Chikungunya viruses; in laboratory and field trials, the bacteria made the mosquitoes resistant to these viruses. Importantly, some strains of Wolbachia that make their hosts resistant to viruses do not appear to cause a serious fitness penalty to their insect host.Our central hypothesis, based on these clear data from other insect species, is that infection with appropriate strains of Wolbachia will make honey bees resistant to important honey bee viruses; these are related to viruses known to be inhibited by Wolbachia. We will test this hypothesis in cultured bee cells, which allows more rapid testing of Wolbachia-virus combinations than using bees. We will also explore effects on the microsporidian parasite, Nosema, as there is some evidence that Wolbachia can also inhibit cellular pathogens. In addition to testing Wolbachia in honey bee cell lines, we can perform direct studies on individual honey bees in laboratory cages. In mosquitoes, adults can be injected with a purified strain of Wolbachia, which will disseminate through the tissues, this is called a 'transient' infection. These insects can then be challenged with viruses to get an indication of the effects of Wolbachia infection. Adult honey bees will be challenged in the same way in a contained environment, as a complementary approach for the potential anti-viral or anti-microsporidian activity of Wolbachia. We propose to investigate the feasibility of using Wolbachia to inhibit positive sense RNA viruses, using a honey bee cell line as initial proof of concept. We will deliver this through four linked objectives:Obj1:Set up cell culture and establish Wolbachia infected and Wolbachia-free derivatives Obj2:Set up viral and Nosema cultures in cell linesObj3:Test pathogen infection on Wolbachia infected and Wolbachia free cell linesObj4:Validate and test transient Wolbachia infections of worker honey beesThere is a clear need for new methods for control of viral and cellular pathogens in bees. This project aims to explore the potential of a Wolbachia-based, non-chemical approach that, if realised, would potentially fit well into an enhanced, sustainable integrated bee health programme. If Wolbachia can inhibit viruses and/or Nosema spp. in honey bees, this would provide an exciting new approach to control of bee diseases; this project will test the feasibility of this approach. Wolbachia is transmitted through the female germline, so Wolbachia infected queen bees could be used to generate disease resistant colonies. This Wolbachia-based approach does not involve the use of recombinant DNA methods and the resulting strains are not considered to be genetically modified organisms (GMOs), providing lower barriers to any eventual field use than some other potential genetic approaches to pathogen resistance.