Abstract

Although their apparent simple morphology, red blood cells (RBCs) are very deformable with well-adjusted rheological properties enabling their fast, efficient and resilient transport into the blood stream. In the spleen, RBCs pass the most stringent physical fitness test of the blood circulation, consisting in squeezing through submicronic slits where they undergo extreme deformations. This test which is believed to filter RBCs by retaining the stiff ones is known to play an important role in many diseases such as malaria or sickle cell disease. However, the mechanisms that govern the cell dynamics through the slits are still unknown. CINAM has developed microfluidic chips with slits of physiological dimensions where RBCs are observed when crossing the slits. The mathematical laboratory I2M is specialist in complex fluid modeling, fluid mechanics, and collective motion. We will combine our expertise to decipher, both from experiments and mathematical modeling, the role of RBC rheological properties (complex fluid-structure interactions) and active processes on their ability to cross the spleen filter. In particular, we will investigate the activation of the mechano-sensitive ionic channel PIEZO1 and its interaction with the Gardos channel resulting in a possible reduction of the RBC volume.