Lorraine Montel
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Lorraine Montel
@lorrainemontel.bsky.social
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CNRS Researcher at Institute of Light and Matter (Univ Lyon1). Insterested in mechanics and mechanotransduction in macrophages, particularly during phagocytosis.
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Internship opportunity for a Master Student
@symux.bsky.social and I are looking for someone to work with us to answer this tantalizing question: does a phagocyte regulates its cell volume during and after phagocytosis?

If you are interested, please do not hesitate to contact us in DM or by e-mail.
Volume control during phagocytosis Supervised by Sylvain Monnier and Lorraine Montel at Institute of Light and Matter, Lyon Scientific context: Phagocytosis is the internalization of large particles (>1μm) by immune cells to protect the organism from pathogens, foreign materials and dying cells. The cell changes shape rapidly to wrap itself around the target particle until the target is sealed in a membrane-bound compartment called the phagosome. As the internalization ends, the cell has to accommodate the volume of one or several phagosomes into its own cytoplasm, displacing organelles and squeezing the nucleus. Membrane availability and tension have been shown to be essential for this process, and phagocytosis can be stalled by the application of osmotic shocks that inflates the cell and thus decrease membrane availability. Yet the influence of the cytoplasmic volume and its regulation during and after phagocytosis is unknown. Volume is a natural feature of cells, controlled by passive and active mechanisms taking place at the plasma membrane. Cell volume is directly affecting cell density, molecular crowding, molecular concentrations and thus biochemical equilibria. Hence volume changes influence cell mechanics, progression through the cell cycle and cell decisions. In this project, we aim to measure the volume of phagocytes before, during and after phagocytosis of large particles to understand whether the cell actively regulates its own volume to accommodate larger objects. The objects will be emulsion droplets that can be modulated in size and functionalized for phagocytosis. These particles can then be presented to macrophages for phagocytosis. Measurements of the cell volume during phagocytosis will be done using FXm, using two dyes. One dye will be excluded from both the cells and the droplets and thus measure the increasing volume of a cell ingesting a particle. The other dye will match the color of the dye in the particles, and thus reveal the changes in volume of the cell itself, not accounting for the particle volume. The project will involve: • cell culture of immortalized macrophages • fabrication and functionalization of oil droplets as artificial particles for phagocytosis • microfabrication of FXm chambers • live microscopy of phagocytosis in FXm • image and data analysis The project will take place in the Biophysics team of the Institut Lumière Matière (iLM) in Lyon, under the supervision of Lorraine Montel, an expert in phagocytosis and the physico-chemistry of droplets, and Sylvain Monnier, an expert in cell volume regulation and its measurement. The institute has all the facilities required for the project (clean room, environmental microscopy, droplet production, etc.). Contacts: lorraine.montel@univ-lyon1.fr or sylvain.monnier@univ-lyon1.fr
December 2, 2025 at 4:17 PM