Equipe 1 - Différentiation lymphocytaire et homéostasie dans l’allo et l’autoimmunité
Antoine Toubert
Groupe 1 – Matthieu Allez – Maladies inflammatoires du tube digestif
Groupe 2 – Ryad Tamouza - Immunogénétique
Equipe 2 - Régulation de la réponse immunitaire allogénique lors d’une transplantation rénale
Nuala Mooney
Equipe 3 - Greffes de cellules souches hématopoietiques
Gérard Socié
Equipe 4 - Physique du cytosquelette et de la morphogenèse
Manuel Théry
Equipe 5 - NK et Cancer
Anne Caignard
Equipe 6 - INKT pathologies
Kamel Benlagha
Date: 11 Dic 2023 - 20:13
Desc: This review summarizes recent advances in micro- and nanopore technologies with a focus on thefunctionalization of pores using a promising method named contactless electro-functionalization (CLEF). CLEF enables the localized grafting of electroactive entities onto the inner wall of a microor nano-sized pore in a solid-state silicon/silicon oxide membrane. A voltage or electrical current applied across the pore induces the surface functionalization by electroactive entities exclusively on the inside pore wall, which is a significant improvement over existing methods. CLEF’s mechanism is based on the polarization of a sandwich-like silicon/silicon oxide membrane, creating electronic pathways between the core silicon and the electrolyte. Correlation between numerical simulations and experiments have validated this hypothesis. CLEF-induced micro-andnanopores functionalized with antibodies or oligonucleotides were successfully used for the detection and identification of cells and are promising sensitive biosensors. This technology could soon be successfully applied to planar configurations of pores, such as restrictions in microfluidic channels.
Date: 3 Oct 2017 - 02:10
Desc: The plasma membrane is the most basic element necessary for the cell to exist and be distinguishable from its environment. Regulated mechanisms allow tightly controlled communication between intacellular and extracellular medium allowing the maintenance of a specific biochemical environment, optimized for cellular functions. The anarchic and uncontrolled opening of a hole in the PM induces a change in the concentration of ions and oxidizing agents perturbing homeostasis. Fortunately, the cell possesses mechanisms that are capable of reacting to sudden extracellular medium entry and to block the leakage locally. Here we summarize the known mechanisms of membrane repair and how the size of the wound and the resulting calcium entry activates preferentially one or another mechanism adapted to the magnitude of the injury.
Date: 4 Sep 2017 - 18:38
Desc: Mechanical forces are key regulators of cell and tissue physiology. The basic molecular mechanism of fiber contraction by the sliding of actin filament upon myosin leading to conformational change has been known for decades. The regulation of force generation at the level of the cell, however, is still far from elucidated. Indeed, the magnitude of cell traction forces on the underlying extracellular matrix in culture is almost impossible to predict or experimentally control. The considerable variability in measurements of cell-traction forces indicates that they may not be the optimal readout to properly characterize cell contractile state and that a significant part of the contractile energy is not transferred to cell anchorage but instead is involved in actin network dynamics. Here we discuss the experimental, numerical, and biological parameters that may be responsible for the variability in traction force production. We argue that limiting these sources of variability and investigating the dissipation of mechanical work that occurs with structural rearrangements and the disengagement of force transmission is key for further understanding of cell mechanics.
Date: 18 Dic 2017 - 16:20
Desc: Primary cilia are sensory organelles located at the cell surface. Their assembly is primed by centrosome migration to the apical surface, yet surprisingly little is known about this initiating step. To gain insight into the mechanisms driving centrosome migration, we exploited the reproducibility of cell architecture on adhesive micropatterns to investigate the cytoskeletal remodeling supporting it. Microtubule network densification and bundling, with the transient formation of an array of cold-stable microtubules, and actin cytoskeleton asymmetrical contraction participate in concert to drive apical centrosome migration. The distal appendage protein Cep164 appears to be a key actor involved in the cytoskeleton remodeling and centrosome migration, whereas intraflagellar transport 88's role seems to be restricted to axoneme elongation. Together, our data elucidate the hitherto unexplored mechanism of centrosome migration and show that it is driven by the increase and clustering of mechanical forces to push the centrosome toward the cell apical pole.
Date: 27 Mayo 2020 - 14:01
Desc: Cellular processes, including morphogenesis, polarization, and motility, rely on a variety of actin-based structures. Although the biochemical composition and filament organization of these structures are different, they often emerge from a common origin. This is possible because the actin structures are highly dynamic. Indeed, they assemble, grow, and disassemble in a time scale of a second to a minute. Therefore, the reorganization of a given actin structure can promote the formation of another. Here, we discuss such transitions and illustrate them with computer simulations.
UMR 1160
Unité mixte de recherche 1160 - Alloimmunité - Autoimmunité - Transplantation
Directeur : Antoine Toubert
Hôpital Saint-Louis
1 avenue Claude Vellefaux
Institut Universitaire d'Hématologie