Leader : Tarek Msadek
Workpackage leader: Institut Pasteur, Dr. Tarek Msadek
WP2.3 will validate the general applicability of the theoretical-experimental approaches developped in the model organism B. subtilis through their application to the Gram-positive pathogens Staphylococcus aureus and Bacillus anthracis . Models developed in WP3.2 and based on the “blueprint” provided by the detailed analysis of B. subtilis will be used to devise and conduct a very specific set of experiments ( i.e. characterisation of specific regulons, targeted genetic modifications) that will then be conducted to most efficiently characterize the operation of regulatory networks controlling pathogenesis in these strains. This will involve:
To analyse the transcriptome, proteome and metabolome of S. aureus and B. anthracis grown in vitro under standardised conditions of iron limitation and oxidative stress;
To generate S. aureus and B. anthracis mutant strains affected in regulators known or predicted to be involved in the control of virulence, including regulatory systems partly conserved in B. subtilis and that have been analysed in WP2.1 and WP2.2. Existing tools will be used and as they become available, the tools developed in WP1.1;
To analyse the transcriptome, proteome and metabolome of mutant S. aureus and B. anthracis strains grown in vitro under standardised conditions of iron limitation and oxidative stress;
To determine pathogens responses, including regulatory mutant strains, when exposed to cell cultures including macrophages and epithelial cells and compare these responses to those obtained under standardised conditions. .
In close collaboration with the Computational Pillar (WP3.1 & WP3.2), WP2.1 and WP2.2 will contribute to establishing a generic strategy of integrated experimental and modelling approaches that will then be applied to Gram-positive pathogens in WP2.3 to validate the generic applicability of the strategy. All the activities described in the Biology Pillar will effectively involve performing experiments required to establish or validate computational methods and models.