Figure 6

Phagocytic and alloantingenic presenting activity of DCs loaded with HT29, HT29-dx and HT29 iNOS^- cells. After a 24 h incubation in the absence (CTRL) or in the presence of 5 μmol/L doxorubicin (doxo), the tumour cells were green-stained with PKH2-FITC and subjected to the phagocytosis assay as described in the Methods section. The dot plot analysis of a phagocytosis assay, representative of three similar experiments performed in duplicate, is shown in panel A. In panel B the phagocytic index is represented as mean ± SE of all the experiments. Versus HT29 CTRL: * p < 0.02. C. DCs unloaded (DC), loaded with untreated tumour cells (CTRL) or loaded with doxorubicin-treated tumour cells (dox), in the same experimental conditions of panel B, were treated with mitomycin C and co-cultured with PBMCs, containing the allogenic lymphocytes. At day 4 cells were labelled with [methyl-³H]deoxythymidine and the cpm were evaluated in a β-counter. The [methyl-³H]deoxythymidine incorporation of lymphocytes alone were 1985.33 ± 298.19 cpm. The Proliferation Index of each culture was calculated as detailed in the Methods section. The experiments were performed in triplicate and the results are expressed as mean ± SE from two experiments with lymphocytes from different donors. Versus DC: * p < 0.01; versus HT29 CTRL: ° p < 0.05.