Induction of Th17/1 cells by DCs loaded with apoptotic but not necrotic tumor cells. T cells were cultured with immature DCs (DC) or immature DCs fed apoptotic (DC + Apop tum) or necrotic myeloma tumor cells (DC + necrotic Tum) for 5 to 7 days. The frequency of IL17-producing cells as well as the profile of the Th17 cells was analyzed by intracellular cytokine flow cytometry after stimulation of the cells with PMA and ionomycin in the presence of GolgiStop. Data shown are for DCs fed with U266 myeloma cells. Similar findings were seen after uptake of OPM2 cells (data not shown). (A) The top panel shows the frequency of Th17 cells; the bottom panel shows the expression of IFNγ or IL2 in IL17-expressing cells. (B) Summary of experiments on 4 separate donors showing the percentage of TH17–1 T cells when T cells are cultured with DCs or DCs loaded with apoptotic or necrotic myeloma tumor cells. *P < .001 for DC + apoptotic cells compared with DC alone and DC + necrotic cell conditions. The data represent means plus SD.