Defining the molecular basis of host-pathogen interaction in bovine TB

定义牛结核病宿主与病原体相互作用的分子基础

• 批准号: BB/N004574/1
• 负责人: Apoorva Bhatt
• 金额: $ 74.87万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FN004574%2F1
• 关键词: Defining; molecular; basis; host; pathogen

The sustainable control of Bovine tuberculosis (bTB) is a major challenge for UK agriculture. bTB is caused by a bacterium, Mycobacterium bovis, that can infect a range of wild and domesticated animals, as well as man. Control of bTB is therefore important for public health as well as animal health and welfare. However, current bTB control measures have been ineffective in the UK. The number of herds newly infected with bTB has doubled every nine years; in 2013 over 6.2 million bTB tests were performed in England leading to the slaughter of over 26,000 cattle at a cost to the taxpayer of almost £100Million. New approaches to halt the spread of infection are desperately needed. Mycobacterium bovis (Mbv) is a close relative of Mycobacterium tuberculosis (Mtb), the causative agent of TB in humans. While some of the mechanisms used by Mtb to cause disease in humans are well characterised, not much is known about the strategies used by Mbv to cause disease in cattle. DNA sequencing of the genomes of Mtb and Mbv have revealed that they share more than 99.9% genetic identity. While both Mbv and Mtb can infect humans, Mbv rarely transmits between humans and is instead spread by contaminated dairy products. On the other hand, Mtb can only cause a mild form of the disease in cattle. The distinct host preference of Mbv and Mtb indicates that the two mycobacterial species have evolved distinct strategies to infect and cause disease in their respective hosts. Through previous studies and our own work, a range of discrete molecular variations have been identified between Mtb and Mbv; these include differences in the expression of proteins, termed MPB70 and MPB83, and lipids, such as 'sulfolipid', between these bacteria. The role of these proteins and lipids in the virulence of Mbv for cattle has however not been defined; in this study we will explore the hypothesis that these molecular differences are among the key reasons why Mbv causes disease in cattle. We will test our hypothesis by first generating genetically-engineered Mbv strains that are 'Mtb-like' with regards to the expression of these lipids and proteins. These strains will then be tested along with their parental Mtb and Mbv strains in cellular infection models. These models will focus on laboratory grown cell cultures of bovine macrophages, cells of the bovine immune system that are the first to encounter and engulf invading Mbv cells. We have initial data to show that these cells respond differently to infection with Mbv and Mtb, and will use the genetically engineered strains of 'Mtb-like' Mbv strains to elucidate the mechanisms used by Mbv to establish infection in cattle. To achieve this we will develop an array of tools and new methodologies, such as the use of fluorescently-labelled Mbv and genetic-knockdown techniques, to study the infected macrophages. These tools will help us monitor critical intracellular components of the macrophage machinery, as well as providing tools for the wider bovine immunology research community. Our findings will shed new light on the molecular components that Mbv uses to cause disease in cattle, information that will help in the long term development of vaccines and diagnostics against this devastating disease for UK agriculture.

牛结核病（bTB）的可持续控制是英国农业面临的重大挑战。bTB是由一种细菌，牛分枝杆菌，可以感染一系列野生和家养动物，以及人。因此，bTB的控制是重要的公共卫生以及动物健康和福利。然而，目前的bTB控制措施在英国无效。新感染bTB的牛群数量每九年翻一番; 2013年，英格兰进行了超过620万次bTB检测，导致超过26，000头牛被屠宰，纳税人花费近1亿英镑。迫切需要新的方法来阻止感染的传播。牛分枝杆菌（Mycobacterium bovis，Mbv）是结核分枝杆菌（Mycobacterium tuberculosis，Mtb）的近亲，结核分枝杆菌是人类结核病的病原体。虽然Mtb用于在人类中引起疾病的一些机制已得到很好的表征，但对Mbv用于在牛中引起疾病的策略知之甚少。Mtb和Mbv基因组的DNA测序显示，它们具有超过99.9%的遗传同一性。虽然Mbv和Mtb都可以感染人类，但Mbv很少在人类之间传播，而是通过受污染的乳制品传播。另一方面，Mtb只能在牛中引起轻微形式的疾病。Mbv和Mtb的不同宿主偏好表明这两种分枝杆菌物种已经进化出不同的策略来感染各自的宿主并在其各自的宿主中引起疾病。通过以前的研究和我们自己的工作，Mtb和Mbv之间已经确定了一系列离散的分子变异;这些包括蛋白质表达的差异，称为MPB 70和MPB 83，以及这些细菌之间的脂质，如“sulfolipid”。然而，这些蛋白质和脂质在Mbv对牛的毒力中的作用尚未确定;在本研究中，我们将探讨这些分子差异是Mbv引起牛疾病的关键原因的假设。我们将通过首先产生在这些脂质和蛋白质的表达方面是“Mtb样”的基因工程Mbv菌株来测试我们的假设。然后在细胞感染模型中对这些菌株及其亲本Mtb和Mbv菌株进行沿着检测。这些模型将集中在实验室培养的牛巨噬细胞，牛免疫系统的细胞，是第一个遇到和吞噬入侵的Mbv细胞。我们有初步数据表明，这些细胞对Mbv和Mtb感染的反应不同，并将使用“Mtb样”Mbv菌株的基因工程菌株来阐明Mbv在牛中建立感染的机制。为了实现这一目标，我们将开发一系列工具和新方法，例如使用荧光标记的Mbv和遗传敲低技术来研究受感染的巨噬细胞。这些工具将帮助我们监测巨噬细胞机器的关键细胞内成分，并为更广泛的牛免疫学研究社区提供工具。我们的研究结果将为Mbv用于引起牛疾病的分子组分提供新的信息，这些信息将有助于长期开发针对这种毁灭性疾病的疫苗和诊断方法。

项目成果

Transposon libraries identify novel Mycobacterium bovis BCG genes involved in the dynamic interactions required for BCG to persist during in vivo passage in cattle.

转座子文库鉴定出新的牛分枝杆菌 BCG 基因，这些基因涉及 BCG 在牛体内传代过程中持续存在所需的动态相互作用。

• DOI: 10.1186/s12864-019-5791-1
• 发表时间: 2019
• 期刊: BMC genomics
• 影响因子: 4.4
• 作者: Mendum TA

Insights into the ancestry evolution of the Mycobacterium tuberculosis complex from analysis of Mycobacterium riyadhense.

• DOI: 10.1093/nargab/lqab070
• 发表时间: 2021-09
• 期刊: NAR genomics and bioinformatics
• 影响因子: 4.6
• 作者: Guan Q;Garbati M;Mfarrej S;AlMutairi T;Laval T;Singh A;Fagbo S;Smyth A;Browne JA;urRahman MA;Alruwaili A;Hoosen A;Meehan CJ;Nakajima C;Suzuki Y;Demangel C;Bhatt A;Gordon SV;AlAsmari F;Pain A
• 通讯作者: Pain A