Autophagy represents a new host-pathogen interface for identification of infectious bronchitis virus proteins that determine virulence

自噬代表了一种新的宿主-病原体界面，用于鉴定决定毒力的传染性支气管炎病毒蛋白

• 批准号: BB/E018521/1
• 负责人: Tom Wileman
• 金额: $ 33.83万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE018521%2F1
• 关键词: Autophagy; represents; new; host; pathogen

Infectious bronchitis is an important endemic disease of chickens and caused by the avian coronavirus infectious bronchitis virus (IBV). Poultry meat is an important food source and during the course of a year approximately 40 x 109 chickens are reared globally. The increasing demand for poultry meat has lead to the introduction intensive farming methods but productivity is often limited by infectious diseases which spread rapidly through high density chicken populations. Importantly for this proposal, a report sponsored by the UK government published in 2005 (http://www.defra.gov.uk/science/Project_Data/Document Library/ZZ0102/ZZ0102 1215_FRP.doc) revealed that the number one cause of economic loss in the UK poultry industry resulting from infectious diseases of chickens was caused by IBV. The virus is not only responsible for respiratory disease, but also causes damage to the kidneys and to egg producing organs of hens, affecting both the production and quality of eggs. Despite the availability of live and inactivated vaccines, IBV continues to be a major problem. The virus causes high morbidity, is ubiquitous world wide, and endemic in the UK, and shows extensive antigenic variation and short lived immunity. These factors lead to high rates of infection and poor cross-protection following infection or vaccination. Most vaccines are given to poultry by spray or in drinking water. Both approaches are rather hit-and-miss. The 'holy grail' of vaccine developers is to have vaccines that can be given by robotic machine to chicks before they hatch. Unfortunately, no existing IB vaccine can be given in ovo because the viruses stop the chicks hatching. One means of controlling IBV is to have a systematic way of generating live attenuated vaccines that provide protection against virulent strains. The reverse genetics necessary for the modification or removal of genes associated with virulence from IBV has been developed by the coronavirus group at the IAH Compton. Together with DEFRA and Intervet International, a major commercial vaccine developer, the IAH coronavirus group are manipulating the genes of IBV to get an optimum balance between attenuation of virulence and capacity to induce immunity. To apply this technology to the rational design of live vaccines it is now necessary to identify genes that contribute to IBV virulence, and understand how they function. Importantly for this proposal, recent work on mammalian coronaviruses, and work on the avian IBV coronavirus at Compton, suggests that virulence may be determined by the way in which cells control virus replication. We have produced IBVs that do not make a series of small proteins called 3a, 3b, 5a and 5b. These viruses grow normally in cell culture and allow chicks to hatch after inoculation in ovo. This shows that we can attenuate IBV by removing non-essential genes, but this is an empirical process because we do not know how the 3(ab) and 5(ab) proteins function in the context of virulence. The purpose of the present grant application to BBSRC is to establish the science behind the empirical observations that we are making. Experiments underpinning this proposal have shown that virulence of IBV may be associated with proteins that control replication, and that these proteins associate with membranes in cells that have the potential to destroy the virus before it can leave the cell. We now want to understand how the replicase proteins avoid destruction, and in this way determine virulence. This will enable us to fine tune our mutants to make viruses that survive long enough to infect chicks 'in ovo', and induce an immune response, but are too weak to harm the chicks and prevent them from hatching.

传染性支气管炎是由鸡冠状病毒传染性支气管炎病毒（IBV）引起的鸡的一种重要地方病。禽肉是一种重要的食物来源，全球每年大约饲养40 x 109只鸡。对禽肉的需求不断增加，导致引进集约化养殖方法，但生产力往往受到通过高密度鸡群迅速传播的传染病的限制。对于这一提议重要的是，由英国政府赞助的2005年出版的报告（http：www.defra.gov.uk/science/Project_Data/Document Library/ZZ 0102/ZZ 0102 1215_FRP.doc）揭示了由鸡传染病引起的英国家禽业经济损失的头号原因是由IBV引起的。该病毒不仅导致呼吸道疾病，而且还会损害母鸡的肾脏和产蛋器官，影响鸡蛋的产量和质量。尽管有活疫苗和灭活疫苗，IBV仍然是一个主要问题。该病毒导致高发病率，在世界范围内普遍存在，在英国流行，并显示出广泛的抗原变异和短暂的免疫力。这些因素导致高感染率和感染或接种疫苗后的交叉保护性差。大多数疫苗通过喷雾或饮用水给家禽接种。这两种方法都是相当偶然的。疫苗开发者的“圣杯”是能够在小鸡孵化之前通过机器人给它们注射疫苗。不幸的是，现有的IB疫苗不能在卵内接种，因为病毒会阻止小鸡孵化。控制IBV的一种方法是有一种系统的方法来产生减毒活疫苗，该减毒活疫苗提供针对强毒株的保护。IAH Compton的冠状病毒研究组已经开发出了用于修饰或去除IBV毒力相关基因所需的反向遗传学。IAH冠状病毒研究组与DEFRA和主要商业疫苗开发商Intervet International一起，正在操纵IBV的基因，以在毒力减弱和诱导免疫力之间取得最佳平衡。为了将这项技术应用于活疫苗的合理设计，现在有必要鉴定对IBV毒力有贡献的基因，并了解它们如何发挥作用。对于该提议重要的是，最近对哺乳动物冠状病毒的研究以及康普顿对鸟类IBV冠状病毒的研究表明，毒力可能取决于细胞控制病毒复制的方式。我们已经生产出不产生一系列称为3a，3b，5a和5 b的小蛋白质的IBV。这些病毒在细胞培养中正常生长，并允许鸡在卵内接种后孵化。这表明我们可以通过去除非必需基因来减毒IBV，但这是一个经验过程，因为我们不知道3（ab）和5（ab）蛋白在毒力背景下如何发挥作用。目前向BBSRC申请资助的目的是建立我们正在进行的经验观察背后的科学。支持这一提议的实验表明，IBV的毒力可能与控制复制的蛋白质有关，这些蛋白质与细胞膜有关，这些细胞膜有可能在病毒离开细胞之前破坏病毒。我们现在想了解复制酶蛋白如何避免破坏，并以这种方式确定毒力。这将使我们能够微调我们的突变体，使病毒能够存活足够长的时间来感染“卵”中的小鸡，并诱导免疫反应，但太弱而不能伤害小鸡并阻止它们孵化。

项目成果

Spherules and IBV.

• DOI: 10.4161/bioe.29323
• 发表时间: 2014-09
• 期刊: Bioengineered
• 影响因子: 4.9
• 作者: Maier HJ;Hawes PC;Keep SM;Britton P
• 通讯作者: Britton P

Virus factories, double membrane vesicles and viroplasm generated in animal cells.

• DOI: 10.1016/j.coviro.2011.09.008
• 发表时间: 2011-11
• 期刊: Current opinion in virology
• 影响因子: 5.9
• 作者: Netherton CL;Wileman T
• 通讯作者: Wileman T

Infectious bronchitis virus generates spherules from zippered endoplasmic reticulum membranes.

• DOI: 10.1128/mbio.00801-13
• 发表时间: 2013-10-22
• 期刊: mBio
• 影响因子: 6.4
• 作者: Maier HJ;Hawes PC;Cottam EM;Mantell J;Verkade P;Monaghan P;Wileman T;Britton P
• 通讯作者: Britton P