FIGURE 5.

mMCP-8 fails to induce leukocyte migration in vitro, whereas it enhances gene expression of chemokines in the ear skin in vivo. A, the ability of mMCP-8 to induce leukocyte migration was examined by using the transwell system in vitro. The indicated types of cells (5 × 10⁵ cells) were placed in the upper chamber, whereas mMCP-8 (black columns), control BSA (white columns), or the indicated chemokines (gray columns) were included in the culture medium of the lower chamber. The number of cells recovered from the lower chamber after 1.5-h incubation (for neutrophils and macrophages) or 2 h incubation (for eosinophils and basophils) at 37 °C are shown (mean ± S.E., n = 4 each). B, C57BL/6 mice were challenged three times at 24 h-intervals with intradermal administration of 10 μg of mMCP-8 or control BSA in the ear skin. The ears of treated mice were excised 6 h after the last challenge and subjected to Q-PCR analysis to access the gene expression of the indicated chemokines (mean ± S.E., n = 9 each). Data shown are representative of three independent experiments. *, p < 0.05; **, p < 0.01; ***, p < 0.001; n.s., not significant.