Model of in vitro mobilization by SDF-1 and SLF. (A) SDF-1 (100 ng/mL) and SLF (10 ng/mL) were added to the upper chamber to form a negative concentration gradient and SDF-1 (100 ng/mL) and/or SLF (10 ng/mL) were added to the lower chamber to mobilize MO7e cells from the upper chamber. (B) The concentration of SDF-1 at a lower concentration (20 ng/mL) with optimal concentration of SLF (10 ng/mL) was added to the upper chamber to form a less severe negative gradient of chemoattractants. SDF-1 at various concentrations (0, 20, 100, and 1,000 ng/mL) and SLF (10 ng/mL) were added to the lower chamber to mobilize the MO7e cells from the upper to the lower chamber. (C) Anti-SLF neutralizing antibody (10 μg/mL) and pertussis toxin (500 ng/mL) were used to respectively inhibit the effects of SLF and SDF-1 on migration of MO7e cells. SLF (10 ng/mL) and/or SDF-1 (100 ng/mL) was added to the lower chamber. SLF (10 ng/mL) and/or SDF-1 (20 ng/mL) was added to the upper chamber. * Designates significant changes from control (P < .02). ** 0% migration.