Cell adhesion during bullet motion in capillaries.
A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis.
Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan;
Naoki
N
Takeishi
School of Engineering, Tohoku University, Aoba, Sendai, Japan; yimai@pfsl.mech.tohoku.ac.jp.
Yohsuke
Y
Imai
Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan;
Shunichi
S
Ishida
School of Engineering, Tohoku University, Aoba, Sendai, Japan;
Toshihiro
T
Omori
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts; and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts.
Roger D
RD
Kamm
Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan; School of Engineering, Tohoku University, Aoba, Sendai, Japan;
Takuji
T
Ishikawa
D002196:Capillaries / Q000378:metabolism* / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement; D003198:Computer Simulation; D006801:Humans; D057446:Hydrodynamics; D036904:Leukocyte Rolling / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008954:Models, Biological; D019007:P-Selectin / Q000378:metabolism*
D008562:Membrane Glycoproteins; D019007:P-Selectin; C084882:P-selectin ligand protein
adhesion; circulating tumor cell; computational biomechanics; leukocyte; ligand-receptor interaction