Isabelle TARDIEUX

Information

Scientific interests and projects

The team has a long lasting interest in combining molecular genetics and cell biology approaches to interrogate how forces and membrane dynamics co-operate during the obligate process of metazoan cell invasion by the Apicomplexa Toxoplasma gondii protozoan parasite. To this end, we have developed state-of-the art high-speed/high-resolution live imaging in conjunction with image processing and kinematic modeling of invading T. gondii tachyzoites. The team has more recently implemented in the lab force microscopy coupled with live fluorescent and super resolution microscopy and introduce nanoprobes/biosensors to also explore how forces can be generated by the free parasites to achieve exceptionally fast gliding in 2D & 3D micro-environments. Additional expertise including precision microfluidics and microfluidics-based micro-patterning, biomimetic and synthetic membrane systems, proteomics and structural biology has been recently achieved in the team, hence providing an ideal position at the interface between cell biology and biophysics to tackle down the yet unknown biomechanical properties of the Toxoplasma and their contribution to parasite fitness. In the context of ParaFrap, we plan continuing/starting to investigate in priority:

1- How the tachyzoite-derived forces coordinate with the host cell surface dynamic biomechanical properties during active invasion,

2- How the tachyzoite-derived forces cope with the parasite/parasite’ organelle deformability to ensure safe motion?

3- How physiologically relevant mechanical constraints could impact the nuclear compartment properties of T. gondii zoites with a focus on chromatin organization and gene expression? This particular research axis results from a tight collaboration with the the ParaFrap member (MH. Hakimi and team).

Top 5 publications of the last 5 years

1. Pavlou G, Milon G, Tardieux I. Intracellular protozoan parasites: living probes of the host cell surface molecular repertoire. Curr Opin Microbiol. 2019 Jul 23;52:116-123. Invited Review. PMID:31349210. doi: 10.1016/j.mib.2019.06.007.

2. Pavlou G, Biesaga M, Touquet B, Lagal V, Balland M, Dufour A, Hakimi MA, Tardieux I. Toxoplasma Parasite Twisting Motion Mechanically Induces Host Cell Membrane Fission to Complete Invasion within a Protective Vacuole. Cell Host Microbe. 2018 Jul 11;24(1):81-96.e5. Epub 2018 Jun 28. PMID: 30008293. doi: 10.1016/j.chom.2018.06.003

3. Tardieux I, Baum J. Reassessing the mechanics of parasite motility and host-cell invasion. J Cell Biol. 2016 Aug 29;214(5):507-15. Invited Review. PMID: 27573462. doi: 10.1083/jcb.201605100. 

4. Bichet M, Touquet B, Gonzalez V, Florent I, Meissner M, Tardieux I. Genetic impairment of parasite myosin motors uncovers the contribution of host cell membrane dynamics to Toxoplasma invasion forces. BMC Biol. 2016 Nov 9;14(1):97. PMID: 27829452. doi: 10.1186/s12915-016-0316-8

5. Bichet M, Joly C, Henni AH, Guilbert T, Xémard M, Tafani V, Lagal V, Charras G, Tardieux I. The toxoplasma-host cell junction is anchored to the cell cortex to sustain parasite invasive force. BMC Biol. 2014 Dec 31;12:773. PMID: 25551479. doi: 10.1186/s12915-014-0108-y.