LAI @ Centuri Scientific Day

Flash talk – DIAZ BELLO Beatriz (LAI): A deep learning-based modular software to locate, track and measure single-cell ADCC over time.

Flash talk – NUÑEZ VIADERO EIDER (LAI): Development of the state of the art technology to monitor protein-folding in real time under physiological conditions.

Flash talk – ROBERT Philippe (LAI): On and off-rates measurements at the single molecular level with laminar flow chamber: a need for new links and linkers.

A new article on living cells guided against a flow by a roly-poly-like mechanism in PNAS

Cellular guidance by chemical or physical signals is essential for many life processes and usually relies on sophisticated biological processes that are still partially elucidated. Microfluidic experiments and mechanical modeling has revealed that the choice for cells to orient themselves against or in the direction of a flow can result from a simple physical bias. They have worked with  keratocytes, cells that form the scale of fishes, and whose morphology is characterized by  broad  flat “front” and a compact protruding front  “back”. A simplified model of a cell with a hemispherical back and a flat rectangular front allows to quantitatively calculate the forces that the flow exerts on each edge. The resulting force stabilizes the cells with a large rear edge against the flow, like a roly-poly that stays upright because of its heavy bottom edge. The researchers’ model successfully predicted the experimentally observed orientation for each cell without adjusting parameter. It is an elegant example where a characterized biological behavior does not result from specialized molecular sensors and a complex cascade of internal biosignals to reorient the cell, but from a simple passive physical bias.

https://www.pnas.org/doi/10.1073/pnas.2210379119

A– Keratocytes descending a flow, the white arrow indicates the direction of the stream. B– Cell morphology seen in 3D by confocal microscopy, with a bulbous back edge and a flat, thin front edge. C– Cell modeling with a hemisphere at the back (red) and a flat rectangle at the front (brown) D– The torques resulting from flow on cell front (red arrow) and cell front (brown arrow) stabilize upstream orientation of cell with larger rear edge, like the torque resulting from gravity stabilizes the standing position of roly-poly toys with large bottom edge. 

This paper was commented on in CNRS (link)

Welcome to Andrzej

We are pleased to welcome for two months Andrzej Kubiak, a visiting post-doc from the Jagiellonian University in Polland. Andrzej’s is mainly interested in hematopoietic stem cells and will be collaborating with Pierre-Henri Puech on an application of single-cell force spectroscopy to investigate adhesion within the bone marrow.

Launch of the BioPhysImmuno International Research Projet (IRP) supported by the CNRS

The BioPhysImmuno IRP project aims to continue a successful collaboration started through a CNRS Projet International de Coopération Scientifique (PICS) project (20218-2021) between two complementary laboratories, one located in Mexico and one in France. The project has been launched with Pierre-Henri Puech acting as coordinator!

For more information: https://phpuech.wordpress.com/biophysimmuno-irp/

Welcome to Florian Dupuy

We welcome Florian Dupuy, our new INSERM engineering assistant. Florian has had extensive experience at the Cochin Insitiute in the parasitology team Biology of Plasmodium Transmission, where he put to use his cellular and molecular biology skills to decipher the plasmodium parasite’s interactions with host cells, a critical step towards finding antimalarial drugs.

Florian will deploy his valued experience in the many projects of LAI for years to come.

Congratulations to Martine, médaille de cristal du CNRS 2022!

Each year, the CNRS awards talented women and men, support staff in research, whose creativity, mastery and innovative flair, contributes to pushing knowledge and to the excellence of French research, with the “médaille de cristal” (crystal medal) 🏅.

We are proud to announce that our engineer Martine Pelicot was chosen as one of the recipients of the 2022 edition. Congratulations!