Bacterial bombs or stress response - how does the environment influence production and function of bacterial outer membrane vesicles?

外膜囊泡（OMVs）是革兰氏阴性细菌通过外膜膨出和选择性地将细菌分子包装在球形囊泡内而自然分泌的。omv是细菌应激反应的一部分，是细菌解毒和生存所必需的。此外，许多其他功能，如生物膜的形成，抗菌活性，营养获取和生物分子的传递，已经被描述。由于其免疫原性，omv也越来越多地用于疫苗开发。尽管取得了这些进展，但人们对OMV的生物发生和决定OMV形成的因素、分子组成以及与宿主细胞的相互作用知之甚少。在这个项目中，我们将研究天然存在于牛肠道中的食源性病原体肠出血性大肠杆菌（EHEC）产生的OMV。它也会在环境中存在很长一段时间，主要是在原生动物体内。在人类中，肠出血性大肠杆菌在结肠中定植，是世界范围内腹泻的主要原因。它还可导致溶血性尿毒综合征，这是一种影响肾脏和中枢神经系统的严重全身并发症。本研究的目的是确定与肠出血性大肠杆菌不同栖息地（牛、人、外部环境）相关的环境条件对OMV产生和功能的影响，特别关注OMV释放、蛋白质组成以及与宿主细胞的相互作用。

Outer membrane vesicles (OMVs) are naturally secreted by Gram-negative bacteria by bulging of the outer membrane and selective packaging of bacterial molecules within spherical vesicles. OMVs are part of the bacterial stress response and necessary for bacterial detoxification and survival. In addition, many other functions such as biofilm formation, antimicrobial activity, nutrient acquisition, and delivery of biomolecules, have been described. Due to their immunogenic properties, OMVs are also increasingly used in vaccine development. Despite these advances, little is known about OMV biogenesis and the factors determining OMV formation, their molecular composition, and interaction with host cells.In this project, we will investigate OMV production by the foodborne pathogen enterohaemorrhagic E. coli (EHEC) which naturally resides in the intestinal tract of cattle. It also persists in the environment for prolonged periods of time, predominantly within protozoa. In humans, EHEC colonises the colon and is a major cause of diarrhoea worldwide. It can also lead to haemolytic uraemic syndrome, a severe systemic complication affecting the kidneys and central nervous system.The aim of this study is to determine the effect of environmental conditions relevant to the different habitats of EHEC (cattle, humans, external environment) on OMV production and function with particular focus on OMV release, protein composition, and interaction with host cells.