CD43-mediated enhancement of (A) MO7e and (B) TF-1 cell adhesion to immobilized fibronectin. Radiolabeled cells were pretreated with medium (RPMI 1640 medium containing 1% BSA) alone, 20 μg/mL control IgG, anti-CD43 MoAb (clone DF-T1), or anti-CD31 MoAb (clone 5.6E) for 20 minutes at 4°C. Next, 10 μg/mL goat antimouse IgG was added for 10 minutes at 4°C. Cells were then distributed in flat-bottom 96-well plate coated with fibronectin. The plate was centrifuged at 600 rpm for 1 minute and incubated for 20 minutes at 37°C. Cell adhesion assay was performed as described in Materials and Methods. Data represent the mean ± standard error (SE) of triplicate assays for one of three reproducible experiments each. *P < .0001 versus control **P < .001 versus control.