Macrophage inflammatory protein-1β (MIP-1β), also known as CCL4 is a CC chemokine with specificity for CCR5 receptors. It is a chemoattractant for natural killer cells, monocytes and a variety of other immune cells. MIP-1β is a kind of chemotactic cytokine. Thus, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of MIP-1β on the human T-lymphocyte leukemia cell line Jurkat. Briefly, Jurkat cells were seeded into the upper chambers (100uL cell suspension, 5×105 cells/mL in RPMI 1640 with FBS free) and recombinant human MIP-1β (0.0001ng/mL, 0.001ng/mL, 0.1ng/mL, 1ng/mL, 10ng/mL, 100ng/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 2h, 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 (×200) randomly (five fields for each filter). Result shows recombinant human MIP-1β 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 (×200). Statistical results were shown in Figure 2. The optimum chemotaxis of MIP-1β occurs at 0.1~10pg/mL.
(A)Jurkat cells were seeded into the upper chambers and serum free RPMI 1640 with 0.01ng/mL MIP-1β was added in lower chamber, then cells in lower chamber were observed at low magnification (×100) after incubation for 2h;
(B)Jurkat cells were seeded into the upper chambers and serum free RPMI 1640 without MIP-1β was added in lower chamber, then cells in lower chamber were observed at low magnification (×100) after incubation for 2h.
Figure. The chemotactic effect of recombinant human MIP-1β on Jurkat cells.

Figure. The chemotactic effect of recombinant human MIP1-βon Jurkat cells.