Rolling and adhesion of PSGL-1Δcyto transfectants on P-selectin is significantly reduced.
Total rolling events in 50 sequential paired images were acquired, recorded, and analyzed as described in “Materials and methods” for K562/FucT-VII cells (A, 1 of 7 experiments) or BJAB/FucT-VII cells (B, 1 of 7 experiments) expressing either full-length or truncated PSGL-1. High numbers of rolling events were recorded for HL60 cells and PSGL-1 transfectants, but rolling was greatly reduced in both PSGL-1Δcyto transfectants. *P < .05 versus PSGL-1 transfectants. (C) Total rolling events were collected as described for panels A and B, but rolling was analyzed at 3 different shear stresses: 1.5, 1.0, and 0.5 dynes/cm2. Total rolling events in 50 fields (1 of 3 experiments) were recorded for HL60 cells (open boxes), K562/FucT-VII/PSGL-1 transfectants (closed triangles), and K562/FucT-VII/PSGL-1Δcyto transfectants (closed circles). High numbers of rolling events were recorded for HL60 cells and PSGL-1 transfectants. In contrast, rolling events were greatly reduced for PSGL-1Δcyto transfectants at the tested shear rates. (D) HL60 (8.8 ± 2.9 cells/COS cell) and PSGL-1 transfectants (7.4 ± 2.32 cells/COS cell) bound at similar levels to COS cells transfected with P-selectin, whereas PSGL-1Δcyto transfectants bound at lower levels (1.7 ± 0.9 cells/COS cell).
