FIG. 6.

MCP-1 is the major soluble chemoattractant for monocytes produced by HUVEC in response to both IL-1 and B. burgdorferi. Conditioned media were collected from HUVEC incubated with either 5 U of IL-1 per ml (IL-1/EC-CM) or B. burgdorferi at a ratio of 10 Bb/EC (Bb/EC-CM) for 24 h. IL-1/EC-CM and Bb/EC-CM were diluted 1:10 in M199 and were either left untreated (No MAb) or incubated with 10 μg of neutralizing anti-MCP-1 MAb per ml. Conditioned media or control medium (No Stim) were tested for chemotactic activity toward monocytes in Boyden chambers. Bars represent the means ± SD of three replicate samples.