Migration of the α_Mβ₂-bearing cells to α_EC and D₁₀₀.

(A) Cells expressing α_Mβ₂ (150 μL; 3 × 10⁵) in DMEM–F-12 medium were added to the upper chambers of transwells and allowed to migrate to different concentrations of α_EC or D₁₀₀ (1, 5, and 100 μg/mL) placed in the lower chamber. Some cells were preincubated with 40 μg/mL mAb 44a or mAb IB4 and allowed to migrate to 100 μg/mL of each domain. Cell migration was assessed after 15 hours at 37°C in a humidified CO₂ atmosphere. Cells from the upper chamber were removed, and migrating cells on the lower surface of the filter were fixed, stained, and counted. Results are the mean ± SE values per field for 6 random fields counted. (B) Migration of U937 cells to α_EC or D₁₀₀. The U937 cells grown in RPMI 1640 were washed twice in the same medium and added to the upper chambers of transwells at a concentration of 2 × 10⁶cells/mL. The lower chambers contained 50 μg/mL α_EC or D₁₀₀. In some experiments, the cells were preincubated with 40 μg/mL mAb 44a and mAb IB4, and migration to 100 μg/mL of each D₁₀₀ or α_EC sample was measured. After 5 hours at 37°C, cells migrating through the 5-μm membrane were fixed, stained, and counted as described above.