Numerical simulation of White Blood Cell rolling on endothelial wall*

Rolling of White Blood Cell (WBC) on endothelial wall plays an important role in the human immune system. The rolling dynamics of RBC contain important information on the characteristics of both WBC membrane and the endothelial bonding. In this work, we replicate this process using numerical simulations. The WBC is assumed to have an idealized spherical shape. A realistic model of blood vessel is reconstructed from in-vivo imaging data. The transport of the WBC in fluid flows is simulated using a fluid-structure interaction approach, which couples the dynamics of the cell membrane in fluid flows. The Dissipative Particle Dynamics is used to model the cellular dynamics (membrane, and cytosol). The cytoskeleton components (actin filament, intermediate filament and microtubes) are modeled using non-linear Worm-Like Chain springs. The extracellular flow is modeled with the Immersed Boundary Method, which allows the efficient simulation of fluid flows in complex vasculatures. We will report and compare the history of WBC rolling as it traverses along the endothelial wall under different flow conditions.