Exploiting African swine fever virus surface proteins to develop rapid diagnostic tests and understand virus host interactions

该项目将调查猪的病毒性疾病非洲猪瘟（ASF），该疾病在受影响国家造成重大经济损失。这些主要是在撒哈拉以南非洲，尽管非洲猪瘟最近已被引入高加索和俄罗斯，增加了进一步全球传播的风险。大多数病毒分离株在猪中引起急性致死性疾病，尽管也有一些毒性较低的分离株。ASF对商业和自给性猪生产具有潜在的破坏性影响。在喀麦隆或马达加斯加等国家，ASF的引入导致50%至80%的猪群损失。非洲猪瘟对粮食安全具有严重影响。猪通常在牛肉生产困难的地区饲养。它们是将食物垃圾和农业副产品转化为高质量蛋白质的绝佳转化器，生产周期相对较短。ASF难以控制有几个原因。这些问题包括在野猪和软蜱媒介中存在ASFV病毒的宿主，缺乏疫苗以及病毒在猪肉和环境中的稳定性。大多数非洲猪瘟疫情没有报告，因此没有实施控制措施。这是因为样本必须提交给参考实验室进行诊断。在许多非洲国家，这些机构要么不存在，要么向它们发送样品费用昂贵，需要很长时间。该项目将通过开发可在当地农场使用的Penside诊断测试来帮助控制ASF。类似的彭赛德试验在其他动物疾病的诊断和控制中发挥了巨大作用，例如在导致全球根除牛瘟或牛瘟的运动中。这些笔侧诊断测试将在短期内商业化。所采取的方法将是将暴露在ASF病毒颗粒表面的蛋白质固定化，然后产生识别这些蛋白质的抗体。ASFV是一种大型复杂病毒，可能需要测试针对几种蛋白质的抗体，以确定最适合用于诊断测试的蛋白质。这些抗体将被整合到简单的设备中，类似于怀孕测试试剂盒，可以在农场使用。这些将用于检测疑似感染ASFV的猪样本中的病毒，从而确保快速准确的诊断。病毒表面蛋白将用于另外两个目的。预期这些蛋白质对于病毒结合并进入宿主细胞以开始产生子代病毒颗粒是重要的。激活宿主的免疫系统来识别这些蛋白质可以抑制病毒感染，保护猪免受ASF疾病的侵害。将测试这些病毒表面蛋白的组合刺激猪的免疫应答并保护它们免受ASF疾病的能力。有希望的候选蛋白质将被纳入针对ASFV的疫苗开发计划。最后，该项目中产生的试剂将用于基础科学研究，以提高我们对ASFV病毒颗粒如何结合并进入宿主细胞以及病毒颗粒如何组装的理解。这些信息将在理解病毒与宿主细胞的相互作用方面具有广泛的科学意义，从长远来看，这可能会导致控制病毒感染的新策略。

This project will investigate a virus disease of pigs, African swine fever (ASF), which causes major economic losses in affected countries. These are mainly in sub-Saharan Africa although ASF has recently been introduced to the Caucasus and Russia increasing the risk of further global spread. Most of the virus isolates cause an acutely fatal disease in pigs, although there are some less virulent isolates. ASF has potentially devastating effects on the commercial and subsistence pig production. In countries such as Cameroon or Madagascar, the introduction of ASF resulted in the loss of between 50 and 80% of the pig population. ASF has serious implications for food security. Pigs are often reared in areas where beef production is difficult. They are excellent converters of food waste and agricultural by-products into high quality protein and have a relatively short production cycle. ASF is difficult to control for several reasons. These include the presence of reservoirs of the virus, ASFV, in wild pigs and soft tick vectors, the lack of a vaccine and the stability of the virus in pork and in the environment. Most outbreaks of ASF are not reported and control measures are therefore not implemented. This is because samples have to be submitted to reference laboratories for diagnosis. In many African countries these are either not present or sending samples to them is costly and requires a long time. This project will aid control of ASF by development of penside diagnostic tests which can be used locally on farms. Similar penside tests have been used to great effect in the diagnosis and control of other animal diseases, such as in the campaign which has resulted in the global eradication of the disease known as cattle plague or Rinderpest. These penside diagnostic tests will be made available commercially in the short term. The approach taken will be to characterise the proteins that are exposed on the surface of the ASF virus particles and then to produce antibodies that recognise these proteins. ASFV is a large complex virus and it may be necessary to test antibodies against several proteins to identify those that are best to use in the diagnostic tests. The antibodies will be incorporated into simple devices, similar to pregnancy testing kits, which can be used on farms. These will be used to detect virus in samples from pigs that are suspected to be infected with ASFV thus ensuring rapid and accurate diagnosis. The virus surface proteins will be used for two other purposes. These proteins are expected to be important for the virus to bind and enter host cells to begin production of progeny virus particles. Activating the host's immune system to recognise these proteins may inhibit virus infection and protect pigs from ASF disease. The ability of combinations of these virus surface proteins to stimulate an immune response in pigs and protect them from ASF disease will be tested. Promising candidate proteins will be incorporated into programmes for vaccine development against ASFV. Finally, the reagents generated in the project will be used for basic scientific studies to improve our understanding of how ASFV virus particles bind to and enter host cells and how virus particles are assembled. This information will be of broad scientific interest in understanding the interaction of viruses with the host cell which in the longer term may lead to novel strategies to control virus infections.