Figure 2
IFN-DC have novel molecular, phenotypical and functional characteristics in comparison to IL-4/TNF-DC. (a) Hierarchical cluster analysis of 52 genes related to NK cell function (rows) for IFN-DC and IL-4/TNF-DC preparations (columns) with expression levels obtained by Affymetrix microarray analysis. The colour scale indicates upregulation (green) and downregulation (red) of gene expression in relation to the mean expression levels of all preparations. (b) Corroboration of the microarray data by quantitative real-time PCR. The ΔCt values of 10 genes with β2-microglobulin as a reference gene were measured. Differences of the relative expression (mean ΔΔCt) of each gene were compared to the log2 of the fold change determined by microarray technology. (c) Expression of cytolytic effector molecules by DC. The intracellular expression of TRAIL and granzyme B by IFN-DC and IL-4/TNF-DC was analyzed by flow cytometry after permeabilization of cell membranes. The results are shown as mean ± SD of % positive cells. (d) Cytolytic activity of DC. Specific lysis of tumor cells by DC was measured by flow cytometric detection of propidium iodide uptake after coculture of 1 × 105 CFDA-SE labeled K562 cells with different numbers of IFN-DC and IL-4/TNF-DC as indicated by the effector : target ratios. IL-2 activated NK-cells were used as a positive, and B cells as negative control. Significant differences between IFN-DC and IL-4/TNF-DC at different effector : target ratios are indicated by an asterisk (p < 0.05).