Biomechanics of cell rolling: shear flow, cell-surface adhesion, and cell deformability.
The mechanics of leukocyte (white blood cell; WBC) deformation and adhesion to endothelial cells (EC) has been investigated using a novel in vitro side-view flow assay. HL-60 cell rolling adhesion to surface-immobilized P-selectin was used to model the WBC-EC adhesion process. Changes in flow shear stress, cell deformability, or substrate ligand strength resulted in significant changes in the characteristic adhesion binding time, cell-surface contact and cell rolling velocity. A 2-D model indicated that cell-substrate contact area under a high wall shear stress (20 dyn/cm2) could be nearly twice of that under a low stress (0.5 dyn/cm2) due to shear flow-induced cell deformation. An increase in contact area resulted in more energy dissipation to both adhesion bonds and viscous cytoplasm, whereas the fluid energy that inputs to a cell decreased due to a flattened cell shape. The model also predicted a plateau of WBC rolling velocity as flow shear stresses further increased. Both experimental and computational studies have described how WBC deformation influences the WBC-EC adhesion process in shear flow.
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Bioengineering Program, The Pennsylvania State University, University Park 16802, USA. cxd23@psu.edu
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D001696:Biomechanical Phenomena; D002448:Cell Adhesion / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D048429:Cell Size / Q000502:physiology; D004727:Endothelium / Q000166:cytology / Q000502:physiology; D018922:HL-60 Cells; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D008954:Models, Biological