Fig. 6. Intracellular cytokine/chemokine analysis of IL-4-DC by flow cytometry. (A) Cells were activated with LPS (1 µg/ml) for 18 hours. Brefeldin A was added to the cultures for the last 4 hours and then intracellular IFN-/IL-4 (upper row) and MlP-1/IL-8 (lower row) were analysed. The percentages of the respective cytokine-producing cells are shown in each dot plot profile. Quadrants were set according to the fluorescence intensities of FITC- and PE-conjugated isotype-matched control Igs with irrelevant specificity. (B) Cells were left untreated or stimulated with anti-CD40 mAb (10 µg/ml) or LPS (1.0 µg/ml) plus IFN- (100 ng/ml) for 18 hours to detect intracellular IL-12/IL-13. Quadrants were set after staining with isotype matched control mAbs. The percent positive cells are given in each quadrant. The flow cytometry results are representative of three similar experiments.