CCL13 (C-C motif chemokine 13) is a chemotactic factor that attracts monocytes, lymphocytes, basophils and eosinophils, which belongs to the CC chemokine subfamily. It has been reported that CCL13 can induce chemotactic migration of THP-1 cells. Therefore, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of CCL13 on the human monocytic cell line THP-1. Briefly, THP-1 cells were seeded into the upper chambers (100µL cell suspension, 106 cells/mL in RPMI 1640 with 0.5% FBS) and CCL13 (50ng/mL and 100ng/mL diluted separately in serum free RPMI 1640) was added in lower chamber with a polycarbonate filter (8µm pore size) used to separate the two compartments. After incubation at 37oC with 5% CO2 for 3h, the filter was removed, then cells in low chamber were observed by inverted microscope at low magnification (×100) and the number of migrated cells were counted at high magnification (×400) randomly (five fields for each filter).
Result: CCL13 is able to induce migration of THP-1 cells. The migrated THP-1 cells in low chamber at low magnification (×100) were shown in Figure 1. Five fields of each chamber were randomly chosen to count the migrated cells at high magnification (×400) and the statistical data was shown in Figure 2.