In vitro functional analysis on monocytes and monocyte-derived DCs. (A) T-cell stimulation potential of uncultured bone marrow monocytes, LPS-treated or untreated DCs from day-3 cultures of monocytes with GM-CSF and IL-4, LPS-treated or untreated macrophages from day-3 cultures of monocytes with M-CSF, and splenic DCs were tested in an MLR assay, using different APC/T-cell ratios. T-cell proliferation was determined by [³H]-thymidine uptake (error bars represent the SD for triplicate cultures). (B) Monocyte reverse transendothelial migration assay. Contour plots show the CD11c-versus-MHC II and F4/80-versus-Ly-6C profiles of reverse transendothelial migrated cells, corresponding to early immature DCs. The percentage of cells in each quadrant is indicated. Data are representative of 3 experiments with similar results.