For ELISAs, cells were plated in triplicate wells the day before treatment in tissue culture, treated in 24-, 48-, or 96-well plate formats (BD Biosciences) and incubated in a 378C humidified incubator with 5% CO 2 . Cells treated in 24well plates were seeded as follows: RAW 264.7 cells at a density of 1 3 10 6 cells/well, HTR-8/SVneo cells at 0.4 3 10 6 cells/well, human monocytes at 1.2 3 10 6 cells/well, and endothelial cells (UtMVECs, HEEC, and HUVECs) at 0.4 3 10 6 cells/well. When the experiments were performed in 48-well plates, the cells indicated above were seeded at half the density as that used in the 24-well plates. BeWo cells and, in some experiments, human monocytes and HEEC were seeded in 96-well plates at a density of 1 3 10 5 , 4 3 10 5 , or 2 3 10 5 cells/ well, respectively. Human macrophages and human monocyte-derived dendritic cells were seeded in 96-well plates at a density of 0.3 3 10 6 cells/ well. SGHPL-4 cells were seeded at a density of 5 3 10 5 cells/well in a 96-well plate.