Figure 5.

Adhesion of neutrophils to fibronectin leads to delayed Vav1 activation but early Syk activation in response to fMLF stimulation. Neutrophils plated on fibronectin (50 μg/ml) or in nonadherent conditions were treated with 1 × 10^–7 M fMLF. After the times indicated, Vav1 and Syk tyrosine phosphorylation (P-Tyr) was determined, as described in Methods. Total Vav1 and Syk levels (anti-Vav1 and anti-Syk IB) were constant with time under each condition. The results shown are representative of three similar experiments obtained with cells derived from different donors.