Autophagy as a defence against zoonotic bacterial pathogens
Lead Research Organisation:
University of Nottingham
Department Name: School of Life Sciences
Abstract
Pathogenic bacteria within the food chain pose a massive health and economic cost. Recent outbreaks have demonstrated the vulnerability of our food supply to contamination and subsequent human disease.
Autophagy is a crucial response to diverse stresses, including bacterial infection. However, we understand relatively little about how the specialised autophagosome vacuole is assembled. It is thought that the autophagosomal membrane is recruited from diverse sources, yet the autophagosome itself is mostly devoid of intramembrane proteins and cholesterol. Thus specific membrane handling proteins are likely required to source, modify and assemble the autophagosome.
We have preliminary data suggesting the OSBP family of sterol-transporters are involved in both autophagy of salmonella and mitophagy (mitochondrial autophagy). You will confirm and extend these observations using gene-knockdown and functional genetic approaches. Knockdown of OSBP2 is expected to reduce autophagy of salmonella and this will be tested using imaging of infected cells. Conversely we have observed over-expression of OSBP2 drives mitochondrial fragmentation, you will test this to see if this represents induction of mitophagy and establish the functional requirements for OSBP2 triggering of mitophagy.
You will perform siRNA gene knockdown and validation, transfection and infection of human cell lines, fluorescence microscopy and quantitative western blotting.
Autophagy is a crucial response to diverse stresses, including bacterial infection. However, we understand relatively little about how the specialised autophagosome vacuole is assembled. It is thought that the autophagosomal membrane is recruited from diverse sources, yet the autophagosome itself is mostly devoid of intramembrane proteins and cholesterol. Thus specific membrane handling proteins are likely required to source, modify and assemble the autophagosome.
We have preliminary data suggesting the OSBP family of sterol-transporters are involved in both autophagy of salmonella and mitophagy (mitochondrial autophagy). You will confirm and extend these observations using gene-knockdown and functional genetic approaches. Knockdown of OSBP2 is expected to reduce autophagy of salmonella and this will be tested using imaging of infected cells. Conversely we have observed over-expression of OSBP2 drives mitochondrial fragmentation, you will test this to see if this represents induction of mitophagy and establish the functional requirements for OSBP2 triggering of mitophagy.
You will perform siRNA gene knockdown and validation, transfection and infection of human cell lines, fluorescence microscopy and quantitative western blotting.
Organisations
People |
ORCID iD |
Alan Huett (Primary Supervisor) |
Publications
Studentship Projects
Project Reference | Relationship | Related To | Start | End | Student Name |
---|---|---|---|---|---|
BB/M008770/1 | 30/09/2015 | 31/03/2024 | |||
1647925 | Studentship | BB/M008770/1 | 30/09/2015 | 29/09/2019 |
Description | Adherent-Invasive Escherichia coli (AIEC) is a non-diarrhoeagenic intestinal E. coli pathotype associated with the chronic inflammatory bowel disease, Crohn's disease. In this project, we have characterised the role of a hypothetical protein previously identified in Collins and Huett (2018) Sci. Data. 5:180081 in motility, biofilm formation, and host colonisation in the prototypical AIEC strain, LF82. We term this protein "biofilm coupled to motility in AIEC," or bcmA. bcmA mutants have a defect in biofilm formation and motility in vitro, and appear less able to colonise the Caenorhabditis elegans gut when in competition with wild-type LF82. This defect is likely due to a decreased ability to swim towards the surface of the gut in the mutant strain, and suggests bcmA may be important for surface colonisation in the human gut, and thus the onset of Crohn's Disease. bcmA appears to be conserved throughout several significant gammaproteobacterial pathogens, including other E. coli, Salmonella, Shigella, and Klebsiella species. Furthermore, the pattern of inheritance does not mirror the phylogenies of strains in which bcmA is present, suggesting bcmA may be horizontally transferred. Taken together, our data suggests bcmA may be an important modulator of motility and host colonisation in a range of prominent human and animal pathogens, including AIEC, and that pathogens may be able to acquire bcmA to promote virulence. A manuscript describing this data is currently in preparation. A conference abstract describing our data ("Offered Paper: An uncharacterised protein mediates motility, biofilm formation, and host colonisation in Adherent Invasive Escherichia coli") is available in the "Infection forum" section of the "Thursday 11 April, Afternoon" section at the URL provided below. |
Exploitation Route | Although our data clearly suggests a role for BcmA in modulation of AIEC motility, we do not currently have any data to suggest a molecular function for this protein. Future work to uncover the molecular mechanism of bcmA is required. The wide conservation of bcmA in a number of significant pathogens may make it of interest to groups working on these pathogens. |
Sectors | Agriculture Food and Drink Healthcare Pharmaceuticals and Medical Biotechnology |
URL | https://microbiologysociety.org/event/annual-conference/annual-conference.html |
Description | Microbiology Society Annual Conference Grant |
Amount | £238 (GBP) |
Funding ID | GA001282 |
Organisation | Microbiology Society |
Sector | Learned Society |
Country | United Kingdom |
Start | 03/2019 |
End | 04/2019 |
Description | Society Conference Grant |
Amount | £305 (GBP) |
Organisation | Microbiology Society |
Sector | Learned Society |
Country | United Kingdom |
Start | 03/2017 |
End | 04/2017 |
Description | "Being a STEM Researcher" talk to end of year 11 students at university library NUAST visit day |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Schools |
Results and Impact | I and one other PhD student gave a talk each to students considering STEM subjects for A-level study at NUAST. My talk detailed my research, how I became a STEM researcher, what doing research is like, and what careers are available to STEM graduates. |
Year(s) Of Engagement Activity | 2016 |