MRC DiMeN Doctoral Training Partnership: Uncovering the molecular mechanisms underpinning A. baumannii virulence

Outline

Antimicrobial resistance (AMR) is a major public health threat. Acinetobacter baumannii, is the leading cause of nosocomial infections worldwide, where its high resistance to antibiotic treatment and ability to cause lethal infections, has led to its categorisation as a “critical priority” pathogen by the WHO¹. New therapeutic approaches, beyond traditional antibiotics, are urgently needed to address the issue. A compelling new approach is to target bacterial virulence factors; specifically reducing pathogen fitness and its ability to cause disease, without exerting a high selection pressure for resistance or affecting commensal bacteria². However, a key limitation in combatting A. baumannii this way, is the current lack of understanding concerning the molecular mechanisms underpinning virulence.

Carboxy-terminal processing proteases (CTPs) are a group of serine proteases, with regulatory PDZ domains, which are found in all domains of life. In bacteria CTPs play critical roles in maintaining cell envelope functions, regulating cellular signalling events, and contributing to virulence. Although universally important, there are very few characterised examples where substrates have been identified and their functional roles resolved. Interestingly, an uncharacterised CTP from A. baumannii contributes to virulence³.

Project

The aim of this project is to fully characterise CTPs from A. baumannii to better understand the molecular machinery involved in pathogenicity and virulence. Structural and biochemical techniques will be employed to unpick the complex regulatory mechanisms of CTPs, and determine the features dictating substrate selection. The functional role of CTPs and their contribution to virulence, will be determined by uncovering the interacting proteins & substrates and evaluating CTP mutants using in vitro and clinically relevant in vivo infection models. These findings will be used to develop peptide inhibitors to block CTP function.

Training

The individual will join an ambitious group seeking to uncover the molecular mechanisms underpinning virulence, which will aid the development of anti-virulence compounds⁴. This project is inter-disciplinary and offers broad training from experts in the fields of structural biology & biochemistry, proteomics and infection biology. Outstanding training and support will be offered to develop a wide range of skills and techniques. The individual, based in the Department of Clinical Infection, Microbiology & Immunology at the University of Liverpool, will benefit from an exceptional research environment with access to excellent facilities & equipment.

Techniques & Skills

Molecular biology – cloning, expression & purification of recombinant proteins

Enzymology – enzyme activity assays (absorbance, fluorescence, etc)

X-ray crystallography – screening crystals, data collection, structure determination

Biophysics techniques – assess protein interactions and stability (e.g. ITC & thermal shift assays)

Chemical biology – peptide design and synthesis

Microbiology – bacterial genome manipulation (Knockout mutations) and assays for bacterial viability, growth and biofilm formation.

Proteomics – mass spectrometry analysis to identify interacting partners and understand interaction sites.

In vitro and In vivo infection models – cytotoxicity assays, Galleria mellonella and murine infection models

Bioinformatics – analysis of DNA and protein sequences and protein structure analysis.

Information

We welcome applications from enthusiastic, highly-motivated and innovative candidates.

To discuss the project, please contact Dr Christopher Harding (Christopher.harding@liverpool.ac.uk). For more information about the supervisory team please see our websites (www.liverpool.ac.uk/people/christopher-harding), (biologicalsciences.leeds.ac.uk/molecular-and-cellular-biology/staff/294/dr-antonio-calabrese) & (www.liverpool.ac.uk/people/aras-kadioglu). 

Benefits of being in the DiMeN DTP:

This project is part of the Discovery Medicine North Doctoral Training Partnership (DiMeN DTP), a diverse community of PhD students across the North of England researching the major health problems facing the world today. Our partner institutions (Universities of Leeds, Liverpool, Newcastle, York and Sheffield) are internationally recognised as centres of research excellence and can offer you access to state-of-the-art facilities to deliver high impact research.

We are very proud of our student-centred ethos and committed to supporting you throughout your PhD. As part of the DTP, we offer bespoke training in key skills sought after in early career researchers, as well as opportunities to broaden your career horizons in a range of non-academic sectors.

Being funded by the MRC means you can access additional funding for research placements, training opportunities or internships in science policy, science communication and beyond. Further information on the programme and how to apply can be found on our website:

https://www.dimen.org.uk/