EspO orthologs and NleF: type III secretion system effectors of enteric pathogens that modulate apoptosis and inflammation

EspO直系同源物和NleF：调节细胞凋亡和炎症的肠道病原体的III型分泌系统效应子

• 批准号: MR/K019007/1
• 负责人: Gad Frankel
• 金额: $ 181.24万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FK019007%2F1
• 关键词: EspO; orthologs; NleF; type; III

Escherichia coli is a bacterium that often inhabits the intestines of warm-blooded animals. Subsets of E. coli have evolved the ability to cause disease. One such group are enterohaemorrhagic E. coli (EHEC), which can cause bloody diarrhoea in humans. Infections can involve life-threatening complications affecting the kidneys and are frequently acquired via the food chain. Enteropathogenic E. coli (EPEC) strains are a related subset of bacteria that cause acute watery diarrhoea in infants in the developing world. Shigella strains, which are closely related to E. coli, cause bacillary dysentery (aka Shigellosis). Shigellosis, which is usually acquired by ingestion of contaminated food or water, remains a global endemic disease responsible for ca. 165 million cases of severe dysentery and 1 million deaths annually, particularly in children less than five years of age. Non-typhoidal Salmonella enterica (NTS) strains cause an estimated 1 billion cases of self-limiting foodborne gastroenteritis annually. More recently, multiple antibiotic-resistant strains have emerged as important causes of fatal invasive bacteraemia, particularly in sub-Saharan regions. Importantly, although considered high priority, no vaccines are yet available for either of these pathogens, the development of which relies on better understanding of their biology and infection strategies.EPEC, EHEC, Shigella and Salmonella rely on a 'molecular syringe' to colonise the intestines and produce disease. This syringe serves to inject a set of bacterial proteins termed effectors into cells lining the intestines. This process, known as Type III secretion (T3S), enables the bacteria to take control of processes inside host cells for their own benefit. Our research has shown that T3S is vital for adherence of EHEC and EPEC to the gut lining and to interfere with the induction of host responses that might otherwise resolve the infection. Infected hosts fight bacterial infection by mounting immune responses while infected cells might assist in clearing the pathogen by undergoing programme cell death (aka apoptosis). Importantly, low-level inflammation may assist the pathogens in establishing a foothold within the host as it modulates the gut physiology and the normal gut flora. It is therefore not surprising that the pathogenic E. coli, Shigella and Salmonella inject T3S effector proteins that subvert both inflammation and apoptosis. We recently found that the EPEC and EHEC T3SS effector NleF binds a host cell protein called caspase-4, which plays a role in both apoptosis and inflammation. Similarly, we found the effector EspO of EHEC, and it's family members in Shigella (OspE) and Salmonella (SopO) bind a host cell protein called Hax-1, which is a major inhibitor of apoptosis and has an indirect role in host immune responses. The broad aim of this work is to characterise the mechanism of action and to understand the role during infection of the EspO family members and NleF. In particular, our aim (which is also our strength) is to translate results obtained by biochemical and cell biology assays in vitro to pathogen-host interactions in vivo. The specific aims include: 1. Determine the structure of the EspO:Hax-1 and NleF:caspase-4 complexes 2. Determine the intracellular interactome of EspO family members and NleF3. Dissect the EspO family members and NleF cell signalling pathways using cell culture models4. Study the role of EspO, SopO and NleF and their host cell partner proteins in pathogen-host interaction in animal models in vivo

大肠杆菌是一种经常栖息在温血动物肠道内的细菌。E.大肠杆菌已经进化出致病的能力。肠出血性大肠杆菌就是其中之一。大肠杆菌（EHEC），可导致人类出血性腹泻。感染可能涉及危及生命的并发症，影响肾脏，并经常通过食物链获得。肠致病性E.大肠杆菌（EPEC）菌株是导致发展中国家婴儿急性水样腹泻的相关细菌子集。志贺菌与大肠杆菌亲缘关系较近。大肠杆菌，引起细菌性痢疾（又名志贺氏菌病）。志贺氏菌病是一种全球性的地方性疾病，通常通过摄入受污染的食物或水而获得。每年有1.65亿例严重痢疾病例，100万人死亡，特别是5岁以下的儿童。据估计，非伤寒沙门氏菌（NTS）菌株每年引起10亿例自限性食源性胃肠炎。最近，多重耐药菌株已成为致命性侵袭性菌血症的重要原因，特别是在撒哈拉以南地区。重要的是，尽管被认为是高度优先的，但这些病原体中的任何一种都没有疫苗可用，这些病原体的开发依赖于对其生物学和感染策略的更好理解。EPEC，EHEC，志贺氏菌和沙门氏菌依赖于“分子注射器”来殖民肠道并产生疾病。这种注射器用于将一组称为效应器的细菌蛋白质注射到肠道细胞中。这一过程被称为III型分泌（T3 S），使细菌能够控制宿主细胞内的过程，为自己的利益服务。我们的研究表明，T3 S对于EHEC和EPEC粘附于肠道内壁并干扰诱导宿主反应至关重要，否则可能会解决感染。受感染的宿主通过建立免疫应答来对抗细菌感染，而受感染的细胞可能通过经历程序性细胞死亡（又名凋亡）来帮助清除病原体。重要的是，低水平的炎症可能有助于病原体在宿主体内建立立足点，因为它调节肠道生理学和正常的肠道植物群。因此致病性E.大肠杆菌、志贺氏菌和沙门氏菌注射T3 S效应蛋白，破坏炎症和细胞凋亡。我们最近发现EPEC和EHEC T3 SS效应子NleF结合一种称为caspase-4的宿主细胞蛋白，该蛋白在细胞凋亡和炎症中起作用。类似地，我们发现EHEC的效应子EspO及其在志贺氏菌（OspE）和沙门氏菌（SopO）中的家族成员结合称为Hax-1的宿主细胞蛋白，其是细胞凋亡的主要抑制剂，并且在宿主免疫应答中具有间接作用。这项工作的主要目的是阐明作用机制，并了解EspO家族成员和NleF在感染过程中的作用。特别是，我们的目标（这也是我们的优势）是将体外生物化学和细胞生物学测定获得的结果转化为体内病原体-宿主相互作用。具体目标包括：1.确定EspO：Hax-1和NleF：caspase-4复合物2的结构。确定EspO家族成员和NleF 3的细胞内相互作用组。使用细胞培养模型剖析EspO家族成员和NleF细胞信号传导途径4。研究EspO、SopO和NleF及其宿主细胞伴侣蛋白在体内病原体-宿主相互作用动物模型中的作用

项目成果

The type III secretion system effector EspO of enterohaemorrhagic Escherichia coli inhibits apoptosis through an interaction with HAX-1.

• DOI: 10.1111/cmi.13366
• 发表时间: 2021-09
• 期刊: Cellular microbiology
• 影响因子: 3.4
• 作者: Chatterjee S;Lekmeechai S;Constantinou N;Grzybowska EA;Kozik Z;Choudhary JS;Berger CN;Frankel G;Clements A
• 通讯作者: Clements A

Model of Host-Pathogen Interaction Dynamics Links In Vivo Optical Imaging and Immune Responses.

• DOI: 10.1128/iai.00606-16
• 发表时间: 2017-01
• 期刊: Infection and immunity
• 影响因子: 3.1
• 作者: Ale A;Crepin VF;Collins JW;Constantinou N;Habibzay M;Babtie AC;Frankel G;Stumpf MPH
• 通讯作者: Stumpf MPH

Bacterial virulence factor inhibits caspase-4/11 activation in intestinal epithelial cells.

• DOI: 10.1038/mi.2016.77
• 发表时间: 2017-05
• 期刊: Mucosal immunology
• 影响因子: 8

The Type III Secretion System Effector SptP of Salmonella enterica Serovar Typhi.

• DOI: 10.1128/jb.00647-16
• 发表时间: 2017-02-15
• 期刊: Journal of bacteriology
• 影响因子: 3.2
• 作者: Johnson R;Byrne A;Berger CN;Klemm E;Crepin VF;Dougan G;Frankel G
• 通讯作者: Frankel G

Enterohaemorrhagic E. coli modulates an ARF6:Rab35 signaling axis to prevent recycling endosome maturation during infection.

• DOI: 10.1016/j.jmb.2016.05.023
• 发表时间: 2016-08-28
• 期刊: JOURNAL OF MOLECULAR BIOLOGY
• 影响因子: 5.6
• 作者: Furniss, R. Christopher D.;Slater, Sabrina;Frankel, Gad;Clements, Abigail
• 通讯作者: Clements, Abigail