T20/DP178 analogs inhibit fMLP binding and abolish cell migration in response to T20/DP178 or fMLP. Different concentrations of DP719 or DP712 were added to aliquots of human monocytes containing a constant concentration of 3H-fMLP. After incubation at 37°C for 20 minutes, the cells were harvested and measured for β emission (A). Unlabeled fMLP at 1 μmol/L was used as a positive control. (B) T20/DP178 (1 μmol/L) or fMLP (100 nmol/L) was placed in the lower wells of the chemotaxis chamber; ETFR cells at 1 × 106/mL in the presence or absence of 50 μmol/L DP917 or DP912 were placed in the upper wells. After incubation, the cells that migrated across the filters were counted. DP917 or DP912 did not affect the cell migration in response to medium alone. DP917 or DP912 also did not by themselves induce ETFR cell migration. *P < .01 (Student’s t-test) compared with the migration of cells incubated with medium alone.
