FIG. 2.
Effect of MAb directed against VLA-4 or β2− integrins on monocytes on adherence of monocytes to EC (A and C) and induction of PCA (B and D) during coculture. Monolayers of 2 × 105 EC/well were incubated for 24 h in medium alone (white bars), with 5 ng of rIL-1/ml (black bars), or with the indicated bacterium (gray bars). After a wash, coculture experiments were initiated by the addition of 2.5 × 105 monocytes. Prior to their addition to EC, monocytes were incubated with 10 μg of anti-CD49d MAb/ml and 10 μg of anti-CD18 MAb/ml in combination (C and D) or in medium alone (A and B). At the indicated times during coculture, the percentage of EC-bound monocytes of the total number of added monocytes was determined as well as the level of PCA generated by the cells. Data are given as the means ± standard deviations for four separate experiments with EC from different donors. (C) P values were 0.007 (∗), 0.003 (∗∗), and 0.017 (∗∗∗) versus the same stimulus at 6 h without MAb (A).