FIG. 8.

IL-10 inhibits the migration of monocytes across HUVEC stimulated by B. burgdorferi but not IL-1. Monocytes were added for 20 min to HUVEC-amnion cultures that had been pretreated for 8 h with control medium (Unstim), 5 U of IL-1 per ml, or B. burgdorferi at a ratio of 10 Bb/EC in the absence (No Addn) or presence of 20 ng of IL-10 per ml. Transendothelial migration was assessed as described in Materials and Methods. The total height of each bar represents the number of monocytes associated with each culture as a percentage of the total added. The lower portion of each bar represents the percentage that migrated beneath the endothelium; the upper portion represents the percentage adherent to the apical surface. Bars represent the means ± SD of three to five replicate samples. This experiment yielded similar results when repeated once using both IL-1- and B. burgdorferi-stimulated samples and three additional times with B. burgdorferi-treated samples only.