MonoMac6 cell migration across fibronectin- or HUVEC-coated filters in response to MCP-1 gradient.

[³H]-methyl thymidine-labeled MonoMac6 cells were washed and loaded in the upper well of the chemotaxis chamber. The lower wells contained either serum-free medium (○) or MCP-1 (●) at different concentrations (A) or 6 nM MCP-1 (B,C). Cell chemotaxis was tested by the ability of MonoMac6 cells to migrate across a fibronectin-coated filter for 4 hours (A) or for different periods of time (B). Transmigration was assayed through a TNF-α–activated monolayer of HUVECs (C) for indicated periods at 37°C. The amount of migrated cells, collected in the lower wells, was evaluated by liquid scintillation β counts as described in “Materials and methods.” Results are expressed as the mean ± SD of triplicates from 3 separate experiments.