Sticky white blood cells deform rapidly when threatened, becoming very stiff and sticky

Like a well-trained soldier, white blood cells use special abilities to identify and ultimately destroy dangerous intruders, including creating a protrusion to effectively contact, lock, detect, and attack its prey

Senior author Julien Husson is a biophysicist at école Polytechnique near Paris.

Husson said: "We know that when forming and using protrusions, cells strongly reorganize their cytoskeleton, and this cytoskeleton plays an important role in imparting mechanical properties to the cell

Stiffness refers to the degree of deformation of a material under a certain pressure, and viscosity refers to the speed at which a material deforms under a certain pressure

The researchers' solution is to apply a force that carefully oscillates around a constant average value

"Although we expected some mechanical changes, our findings were surprisingly dramatic," Husson said

"Interestingly," Husson said, "mechanical changes begin even before any shape changes," which raises the question of whether these significant changes to the mechanical properties of white blood cells are the result of other functions or have their own uses.

The answer to this question may lie in another result of the study: Husson and his colleagues found that the hardness and viscosity of cells change together at a fixed ratio, which is unique to the cell type, like a mechanical fingerprint

In summary, the results of this paper indicate a potential physical mechanism that can be widely applied to cell types, and lead to new models, theories, and ultimately a better understanding and control of our cells in our immune system and other fields.

References: Alexandra Zak, Sara Violeta Merino-Cortés, Ana?s Sadoun, Farah Mustapha, Avin Babataheri, Stéphanie Dogniaux, Sophie Dupré-Crochet, Elodie Hudik, Hai-Tao He, Abdul I.