MoAb to E-selectin blocks transendothelial migration of primary CFU. CB-derived CD34+ cells (105cells/plates) were plated in the upper chamber of 5-μm 24-well costar plates coated with confluent monolayers of IL-1β–activated BMEC. Serum-free X-vivo medium was added to the control wells. After 24 hours of incubation at 37°C, the number of migrating CFU were examined by agarose assay. In the absence of SDF-1, there was spontaneous migration of 29.6% ± 4.9% of added BFU-E (A), 22.3% ± 5% of CFU-GM (B), and 1.4% ± 0.3% of CFU-Mix (C). In the presence of SDF-1, there was an additional migration of 14.2% ± 9.3% of BFU-E (A), 19.1% ± 8.6% of CFU-GM (B), and 1.75% ± 0.37% of CFU-Mix (C) (N = 4,P < .01). However, in the presence of MoAb to E-selectin (10 μg/mL), there was inhibition of the SDF-1–induced migration of 61.8% ± 14.5% of CFU-GM (B) and 48.6% ± 15.0% of CFU-MIX (C) (N = 4). In addition, MoAb to E-selectin inhibited the SDF-1–induced BFU-E migration even below spontaneous levels to 23.2% ± 5.0% (A) (N = 4, P < .05). When taking the total CFU (D) into account, there was spontaneous migration of 53% ± 7% of the added CFC in the control samples. SDF-1 induced additional migration of 41.8% ± 11.0% of the added CFU, and MoAb to E-selectin completely blocked this SDF-1–induced migration by 91.6% ± 13.0% (N = 4, P < .05).
