Figure 2. The chemotactic effect of recombinant mouse MCP1 on THP-1 cells

Monocyte Chemotactic Protein 1 (MCP1), also known as C-C motif chemokine 2(CCL2), is a member of the β (C-C) subfamily of chemokines that is a chemoattractant for monocytes and basophils. Mouse CCL2 is secreted as a 14 kDa glycoprotein monomer but noncovalent dimers probably occur. CCL2 is best known as a chemotactic agent for mononuclear cells. Thus, chemotaxis assay used 24-well microchemotaxis system was undertaken to detect the chemotactic effect of recombinant mouse MCP1 on the THP-1 cell line. Briefly, THP-1 cells were seeded into the upper chambers (150 ul cell suspension,106 cells/ml in RPMI 1640 with FBS free) and different concentrations of recombinant mouse MCP1 diluted with serum free RPMI 1640 was added in lower chamber with a polycarbonate filter (8 um pore size) used to separate the two compartments. After incubation at 37 ℃ 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). Result shows recombinant mouse MCP1 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. Statistical results were shown in Figure 2. The optimum chemotaxis of MCP1 occurs at 0.1 ng/ml.