Calcium Signaling and Microbial Infections
The team is studying the mechanisms of invasion by pathogenic bacteria.
The main model studied is the enteroinvasive bacterium Shigella, the agent of bacillary dysentery, which invades colonic epithelial cells, replicates intracellularly and disseminates from cell to cell, inducing colonization and destruction. of the colonic mucosa. Specifically, we investigate the mechanisms of cytoskeleton diversion and calcium signaling induced by bacterial effectors injected into the epithelial cell. The team is also studying calcium signaling associated with the mechanism of crossing the blood-brain barrier by pneumococcus, a commensal bacterium of the nasopharyngeal mucosa and major causative agent of bacterial meningitis.
Cellular and molecular diversion by Shigella type III effectors
A, Ca2+ microdomain at a Shigella invasion site induced by the type III secretion system. Top panels: Time-lapse pseudocolor images of cells loaded with the Ca2+ probe Fluo-4 infected by Shigella. Frame interval: 4 seconds. Arrow: Shigella invasion site. Bottom panels: Shigella invasion sites labeled for F-actin (red), inositoltrisphosphate receptor type 1 (green) and Shigella LPS (Blue). Adapted from Sun CH et al., EMBO Journal, 2017.
The team’s work involves cellular systems of infections reconstituted in vitro, using different techniques of quantitative dynamic fluorescence microscopy (Ca2+imaging, TIRF, FRAP, FRET, etc.), integrated approaches of molecular and cellular biology, biochemistry and structural modeling. The team develops interdisciplinary projects involving national and international collaborations with mathematical modellers, biophysicists and membrane chemists.
The team’s work involves cellular systems of infections reconstituted in vitro, using different techniques of quantitative dynamic fluorescence microscopy (Ca2+imaging, TIRF, FRAP, FRET, etc.), integrated approaches of molecular and cellular biology, biochemistry and structural modeling. The team develops interdisciplinary projects involving national and international collaborations with mathematical modellers, biophysicists and membrane chemists.
Pneumococal microcolony in a mouse cerebral cortex.
3D reconstruction of planes by confocal microscopy of a brain slice of an infected mouse after intravenous injection of bacteria. Green fluorescence: PN capsule; red: vascular endothelium; grey: GFAP (glial fibrillary acid protein). Scale bar = 7 mm.
team
Guy TRAN VAN NHIEU
Group Leader
Researcher
Laurent COMBETTES
Researcher
Sylvie THIETRY
Assistant Engineer
Mariem HAMED
Engineer
Ilaria PONTISSO
PhD student
Benjamin COCOM-CHAN
PhD student
Benjamin COCOM-CHAN
PhD student
Fangrui GUO
PhD student
Hanane MECHRI
PhD student
Yosra ZARROUK
INSAT intern
Daniel GOICOCHEA-PAREDES
M2 student
Latest publications
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External funding
