Figure 4.

CCR7 expression and migratory capacity. Histogram overlays comparing the CCR7 expression on (a) short-term cultured and (b) long-term cultured IL-15 DCs, either at the immature stage (iDC) or at the mature stage (cc-mDC: + TNF-α, IL1β, IL-6 and PGE₂ for the last 24 hours; TLR-mDC: + R-848, IFN-γ, TNF-α and PGE₂ for the last 24 hours). Bold-line histograms represent the CCR7-specific staining, whereas the corresponding isotype controls are indicated by grey-filled histograms (n = 3). (c) Migration of the indicated DC subsets towards CCL21 in a Transwell chemotaxis assay. The mean ± SEM percentages of migrated cells after 180 min were calculated according to the formula specified in "Methods" (n = 3-6; *, P = 0.01). The values shown in the grey bars represent the cell viabilities of the different DC subsets (mean ± SEM; n = 3-6).