Activating and inhibitory molecules polarize with different kinetics to the interface of conjugates between mature DCs and resting NK cells. Single cell cultures or cocultures of mature DCs with resting NK cells were fixed after 1 or 20 minutes of interaction and f-actin (green), nuclear DNA (blue) and IL-15Rα, IL-12, IL-12R, CD94, KIRs, or MHC class I (red) were stained. Arrows indicate molecule enrichment at the synapse. The graph represents the quantification of molecule staining intensity at the synapse, compared with the staining at the opposite side of the same conjugated cell. Values were normalized to the values of molecule distribution in unconjugated cells, assigned as 1. Images are representative of at least 3 independent experiments. Original magnifications are 100× for all the microscopy images. Values on graph bars represent medians from the analysis of at least 100 conjugates, from at least 3 independent experiments. Error bars indicate interquartile ranges. ↑↑ indicates fold enrichment > 2 for molecules that exist in both DC and NK cell (IL-15Rα and MHC class I); and ↑, fold enrichment > 1.5 for molecules that exist in only 1 cell (IL-12, IL-12R, CD94, and KIRs). Scale bars are 10 μm.