Figure 2.

OX40 ligand (OX40L) expression on monocyte-derived dendritic cells (DC), in the presence or absence of stimulation with monocyte-conditioned medium (MCM). Purified monocytes were cultured in RPMI-1640 supplemented with granulocyte–macrophage colony-stimulating factor (GM-CSF), interleukin-4 (IL-4) and autologous plasma for 7 days to generate immature DCs. Then, cells were cultured for a further 2 days, with or without MCM. Cells were stained with fluorescein isothiocyanate (FITC)-conjugated anti-human leucocyte antigen (HLA)-DR, biotinylated anti-OX40L (ik-1), and phycoerythrin (PE)-labelled streptavidin, and subsequent flow cytometric analysis, with a FACScan, was performed. The percentage of OX40L⁺ HLA-DR⁺ cells is indicated in the upper right corner of each dot-plot.