Chemotactic activity of F peptide for monocytes and neutrophils. Different concentrations of F peptide were placed in the lower wells of the chemotaxis chamber. Monocytes or neutrophils were placed in the upper wells. After incubation at 37°C, the cells that migrated across the polycarbonate filter were counted and photographed. (A) Visualization (original magnification × 400) of neutrophil (upper panels) and monocyte (lower panels) migration in response to control medium (Medium), F peptide (F pep; 5 × 10−5 mol/L), and fMLF (fMLP; fMLP 10−7 mol/L). Solid arrows in the figure denote cells migrated across the filters. An open arrow in the upper-left panel indicates one of the micropores in the filter. (B) Fold increase (chemotaxis index) of phagocyte migration in response to F peptide over control medium. *P < .01 compared with spontaneous migration. (C) Inhibition of monocyte migration in response to F peptide by pertussis toxin. Cells preincubated with 100 ng/mL pertussis toxin (PT) at 37°C for 30 minutes were washed and examined for migration induced by different concentrations of F peptide. Cholera toxin (CT) at 100 ng/mL had no effect on monocyte migration induced by F peptide. *P < .01 compared with migration of cells incubated with medium alone.
