Mast cell supernatant-induced chemotaxis of human Mo. Mo were purified by Percoll gradient centrifugation. Purified Mo were placed in the upper chambers of the chemotaxis assay. Various concentrations of rhMCP-1 (as indicated), various dilutions of HMC-1 sup, various dilutions of lung MC sup (91% pure lung MC, 2-hour incubation, 1,923 pg/mL of MCP-1 by ELISA), FMLP (10−7 mol/L = 10E-7 mol/L) (as positive control) or control medium were added into the lower chambers. MCP-1 and sup of MC or HMC-1 were applied in the presence or absence of blocking anti–MCP-1 antibody S101 (10 μg/mL). After 3 hours of incubation, the nonmigrated Mo were removed together with the filter, and the migrated Mo were recovered from the lower chambers and counted by use of the fluorescence dye calcein AM (5 mmol/L). The X-axis shows the percentage of migrated Mo as compared with the control (=number of Mo migrated against control medium into the lower chambers = 100%). Results represent the mean ± SD from three independent experiments.
