P-selectin expressed on CHO cells triggers genistein-sensitive β2-integrin–dependent adhesion and stimulates protein-tyrosine phosphorylation in PMN. (A) HE-loaded wild-type CHO or P-selectin expressing CHO (CHO-P) cells were incubated in suspension with PMN at a final ratio of 1:5 in standard conditions. The anti-CD18 antibody (IB4) was preincubated with PMN and the anti–P-selectin antibody (WAPS12.2) was preincubated with CHO-P for 15 minutes. PMN were pretreated with genistein (10 μg/mL; GEN) as in Fig2. The interaction was stopped at different times and samples processed for FACS analysis. Data report the percentage of CHO cells binding PMN. Values are means ± SEM, n = 3 to 5. (B) PMN and CHO-P were coincubated as reported above. The interaction was stopped at the indicated times or at 2 minutes, when the effect of antibodies was investigated. The figure shows the Western blot from a representative of three different experiments and the corresponding optical density of P∼110 (means ± SEM, n = 3).
