Adhesion between two nucleated cells undergoes specific significances in immune responses and tumor metastasis since cellular adhesive molecules usually express on two apposed cell membranes. However, quantification of the interactions between two nucleated cells is still challenging in microvasculature. Here distinct cell systems were used, including three types of human cells (Jurkat cell or PMN vs. MDA-MB-231 cell) and two kinds of murine native cells (PMN vs. liver sinusoidal endothelial cell). Cell movement, compression to, and relaxation from the counterpart cell were quantified using an in-house developed gas-driven micropipette aspiration technique (GDMAT). This assay is robust to quantify this process since cell movement and contact inside a pipette are independent of the repeated test cycles. Measured approaching or retraction velocity follows well a normal distribution, which is independent on the cycle period. Contact area or duration also fits a Gaussian distribution and moreover contact duration is linearly correlated with the cycle period. Cell movement is positively related to gas flux but negatively associated to medium viscosity. Cell adhesion tends to reach an equilibrium state with increase of cycle period or contact duration. These results further the understanding in the dynamics of cell movement and contact in microvasculature. (C) 2015 Elsevier B.V. All rights reserved.
This work was supported by the National Natural Science Foundation of China grants 31230027 and 31110103918, National Key Basic Research Foundation of China grant 2011CB710904, and Strategic Priority Research Program of Chinese Academy of Sciences grant XDA01030102.
Chinese Acad Sci, Ctr Biomech & Bioengn, Key Lab Micrograv, Natl Micrograv Lab, Beijing 100190, Peoples R China; Chinese Acad Sci, Beijing Key Lab Engn Construct & Mech, Inst Mech, Beijing 100190, Peoples R China