Inhibition of monocyte chemotaxis to chemokines by F peptide. Monocytes were preincubated with or without F peptide (5 × 10⁻⁶ mol/L) for 60 minutes at 37°C and washed 2 times with PBS. Different concentrations of MIP-1β or SDF-1 were placed in the lower wells of the chemotaxis chamber. Monocytes were placed in the upper wells. After incubation for 90 minutes at 37°C, the cells that migrated across the polycarbonate filter were counted. The chemotactic activity was expressed as CI. *A significantly reduced migratory response of F peptide-pretreated monocytes to chemokines compared with medium-treated cells (P < .05).