Figure 1.
Tethering and rolling of NK cells on L-selectin under flow conditions. (A) Freshly isolated NK cells were perfused at the indicated shear stress (dyne/cm2) over immobilized L-selectin for a 5-min period. Interacting cells were determined by analysis of videotapes in which two fields (0.14 mm2 per field) on a video monitor were counted throughout the flow period. Values represent mean ± SEM of results from three experiments. (B) Cells were perfused at 1.25 dyne/cm2 over immobilized L-selectin either in the continued presence of 5 mM EDTA, after preincubation of the substrate with a blocking anti-L-selectin mAb (LAM1-3), after preincubation of NK cells with a blocking anti-PSGL-1 mAb (PL1), or after treatment of NK cells (solid bars) or U937 (shaded bars) with mocarhagin. The percentage of inhibition for each condition is calculated relative to the untreated control. Data represent mean ± SEM of results from three experiments. (C) Flow cytometric analysis of KPL1 mAb (continuous line; isotype-matched control mAb, dotted line) binding to NK cells incubated for 30 min in the absence (Upper) or presence (Lower) of mocarhagin (mean fluorescence intensity, MFI; x axis, fluorescence, 4-decade log scale).