Interleukin 8 (IL8 or chemokine (C-X-C motif) ligand 8, CXCL8) is a chemokine produced by macrophages and other cell types such as epithelial cells, airway smooth muscle cells and endothelial cells.Thus, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of IL8 on the human T-lymphocyte leukemia cell line Jurkat. Briefly, Jurkat cells were seeded into the upper chambers (100ul cell suspension,106 cells/ml in RPMI 1640 with FBS free) and recombinant Simian IL8 (1ng/ml, 10ng/ml ,100ng/ml and 1000ng/ml diluted separately in serum free RPMI 1640 ) was added in lower chamber with a polycarbonate filter(8um pore size) used to separate the two compartments. After incubation at 37℃ with 5% CO2 for 90min, 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 shows IL8 is able to induce migration of Jurkat cells. The migrated Jurkat cells in low chamber at low magnification(×100) were shown in Figure 1. Five fields of each chamber were randomly chosen, and the migrated cells were counted at high magnification(×400). Statistical results were shown in Figure 2. The optimum chemotaxis of IL8 occurs at 10-100ng/ml.

Figure 2.The chemotactic effect of recombinant Simian IL8 on Jurkat cells