Induction of phagocyte migration by T20/DP178. Different concentrations of T20/DP178 were placed in the lower wells of the chemotaxis chamber; cell suspension was placed in the upper wells. The upper and lower wells were separated by polycarbonate filters. After incubation, the cells migrated across the filters were stained and counted. (A) Migration of neutrophils (upper panel) and monocytes (lower panel) across the filters in response to 100 nmol/L T20/DP178 or fMLP (original magnification × 200). (B) Fold increase of leukocyte migration in response to T20/DP178 over control medium. (C) Inhibition of monocyte migration in response to T20/DP178 by pretreatment of the cells with pertussis toxin (PT; 100 ng/mL for 30 minutes at 37°C). CT, cholera toxin.