Human CCL21 protein, His tag (active)

Secondary Lymphoid-tissue Chemokine (SLC) is a recently identified CC chemokine that is constitutively expressed in various lymphoid tissues and is a potent and specific chemoattractant for lymphocytes. Thus, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of SLC on the human T-lymphocyte leukemia cell line Jurkat. Briefly, Jurkat cells were seeded into the upper chambers (100 μl cell suspension, 1x10⁶ cells/ml in RPMI-1640 with FBS free) and SLC (1 ng/ml, 15 ng/ml and 150 ng/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 37ºC with 5% CO₂ for 1h, 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). The migrated Jurkat cells in low chamber at low magnification (×100) randomly, and the migrated cells were counted at high magnification (×400). SLC is able to induce migration of Jurkat cells, and the optimum chemotaxis of SLC occurs at 15-150 ng/ml.