Tethering and rolling of transfected CHO cells on murine P-selectin.
(A) CHO cells expressing Core2GlcNAcT-I, FTVII, and either wild-type PSGL-1 or the indicated mutant murine PSGL-1 construct were perfused over captured murine P-selectin/IgM at the indicated wall shear stress. After 4 minutes, the number of rolling cells was quantified. (B) Transfected CHO cells were allowed to accumulate on murine P-selectin/IgM at 0.5 dyn/cm2 and cell-free buffer was then introduced. Wall shear stress was increased every 30 seconds, and the percentage of remaining adherent cells was determined. (C) The number of cells that tethered to murine P-selectin/IgM during the first 60 seconds was quantified and normalized by dividing by the number of cells delivered across the field of view in the focal plane of the substrate. The percentage of tethers that were transient or that were converted to rolling adhesion is also indicated. The P-selectin/IgM density was 31 sites/μm2. The data represent the mean ± SEM of at least 4 independent experiments. For some points, the error bars are smaller than the data symbols.
