Coculture with ECs suppresses monocyte activation in a contact-independent manner. (A) Schematic of coculture of monocytes (THP-1 or primary monocytes) with ECs (HUVECs) using a transwell apparatus (1 μm pore size). (B) Coculture of THP-1 monocytic cells with ECs for 48 hours results in a suppressed responsiveness to a 2-hour LPS stimulation, as assessed by qRT-PCR analysis of proinflammatory genes (normalized to GAPDH). Data are relative to gene expression in THP-1 cells grown in EC medium in monoculture. Shown is the mean ± SEM of 6 independent experiments. (C) Coculture of primary monocytes with ECs for 24 hours results in suppressed LPS responsiveness, as assessed by qRT-PCR analysis of proinflammatory genes (normalized to GAPDH). Shown is the mean ± SEM of 8 independent experiments. (D) THP-1 monocytic cells cocultured with membrane-labeled ECs for 24 hours take up the label. Shown is a representative confocal image. The cell nucleus is stained with 4,6 diamidino-2-phenylindole (DAPI). Scale bar, 10 μm.