Identification and manipulation of factors that control Shigella flexneri entrapment in septin cages.

Project Information

CAGECONTROL

Grant agreement ID: 895330

DOI

10.3030/895330

Project closed

EC signature date 16 April 2020

Start date 1 February 2021

End date 31 January 2023

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 224 933,76

EU contribution

€ 224 933,76

Coordinated by

LONDON SCHOOL OF HYGIENE AND TROPICAL MEDICINE ROYAL CHARTER
United Kingdom

Periodic Reporting for period 1 - CAGECONTROL (Identification and manipulation of factors that control Shigella flexneri entrapment in septin cages.)

Reporting period: 2021-02-01 to 2023-01-31

Summary of the context and overall objectives of the project

Shigella flexneri is an important human pathogen responsible for more than 150 thousand deaths a year in low and middle-income countries and is highlighted as an urgent health threat by the WHO due to the lack of an effective vaccine and the emergence of antibiotic resistant strains. In addition to its clinical importance, the study of S. flexneri benefits from a great experimental toolbox due to its genetic proximity to Escherichia coli. For this reason and after more than 30 years of fundamental research, S. flexneri has become a paradigm to study intracellular infection. This means that many of the fundamental mechanisms of bacterial pathogenicity and host response discovered with S. flexneri can also be applied to other important human pathogens. In particular, research on S. flexneri has contributed to the discovery of multiple cell autonomous immune mechanisms that hold great promise for human health impact.

One of these cell autonomous immune responses is controlled by septins, a poorly studied component of the host cytoskeleton. In 2010, septins were shown to entrap intracellular S. flexneri in cage-like structures, which prevent their motility and dissemination to neighbouring cells. The project CAGECONTROL aims to further understand the process of formation of septin cages. Hosted in Prof. Serge Mostowy lab at the London School of Hygiene and Tropical Medicine, the projet “CAGECONTROL: Identification and manipulation of factors that control Shigella flexneri entrapment in septin cages” had two main objectives: a) What is the breadth of factors that determine septin-cage formation? and b) Can we manipulate septin cages to control the fate of S. flexneri during infection?

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project CAGECONTROL aimed to interrogate the host-bacterial interface to discover novel factors that impact on S. flexneri infection and the formation of septin cages using innovative technological tools. This project enabled two main results:

1. I established high-content microscopy in the Mostowy lab in order to unravel the heterogeneity of the infection process. For this, I developed multiple microscopy analysis pipelines to characterise fundamental parameters of the infection process (eg. infection dissemination). In addition, I developed tailored artificial intelligence based analysis to automatically identify septin cages. This has enabled to gain knowledge of the characteristics of S. flexneri entrapped in septin cages and has opened the door to perform genetic and chemical screenings in the lab.

2. I developed novel biochemical approaches to identify novel host factors important during S. flexneri infection as well as septin interactors. These novel approaches have improved our knowledge S. flexneri infection (potentially revealing novel druggable targets for therapeutics). In addition, these methods are highly versatile and can be also applicable to other bacterial species and models of infection.

During the project CAGECONTROL, I exploited and disseminated the results obtained through multiple channels. These include attendance to conferences where I presented my research (Cell Dynamics: Host-Pathogen Interface, UK, 8th - 11th May 2022; UK Cellular Microbiology Network: exploring the host-pathogen interface, UK, 21st – 22nd April 2022; Molecular and Cellular Biology of Septins, EMBO Workshop, Germany, 12th - 15th Sep 2021; UK Cellular Microbiology Meeting, online, 1st - 2nd March 2021). In all of these conferences I have been selected to present my work as a “flash talk” and poster. In addition, I have been invited to give a seminar at the 1st Symposium on Machine Learning for Infection and Disease (Gorlitz, Germany, 15th – 16th Sep 2022). In terms of scientific publications, I have published 2 reviews and 3 scientific articles as collaborator. The main results of the project CAGECONTROL are expected to be published in two different first author articles in high-ranking peer-reviewed scientific journals.

The dissemination of the project CAGECONTROL has also targeted diverse audiences through multiple outreach activities. As an example, I have been a volunteer at the European Researchers Night, Natural History Museum, London (UK, 2019), where I discussed bacterial infections and antibiotic resistance with museum visitors at the station “Dialog Den”. I also participated in the Marie Sklodowska-Curie action “Science is Wonderful!” (online, 2022), where discussed about infection biology with primary school and secondary school students located in Spain. Finally, I founded and chaired the London Infection Postdoc Network (LIPN, https://londoninfection.wixsite.com/home) a collaborative interdisciplinary platform to increase networking opportunities among early career researchers working on infection biology from multiple London research institutes.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The Marie Curie fellowship has provided me with unique opportunities for training. I have acquired new knowledge (e.g. genetic modification of S. flexneri), expanded my technical repertoire (biochemical and molecular biology expertise, as well as microscopy and image analysis knowledge) and broaden my collaboration network. Finally, I have been exposed to in vivo zebrafish infection models to explore the translational impact of my research. I had the pleasure to mentor two M.Sc students and a scientific officer, as well as to work with internal and external collaborators (resulting in 3 collaborative research articles in press and under revision, and more to come). In addition, I transferred my microscopy expertise through the dedicated courses and workshops.

The results obtained during the project CAGECONTROL provide deeper understanding to the process of S. flexneri infection in human cells and in particular the entrapment of intracellular bacteria in septin cages. Together with the innovative and unique tools generated during this project, CAGECONTROL has contributed to generate scientific knowledge, prompted novel research questions and inspire research avenues on infection biology. In the current era of increased antibiotic resistance, fundamental understanding of host-pathogen interactions is paramount to develop novel strategies and therapies to improve human health.

Revealing the heterogeneity of septin cages