DC/Apo-Nec cross-present MelanA/MART-1 and gp100 Ags to specific T CD8+ cells. Overnight IFN-γ secretion from G154 clone specific for gp100 (A) and M27 clone for Melan A/MART-1 (B) Ags after different stimuli (indicated in the left side) was measured by ELISA as described under Methods. To allow cross-presentation for this experiment, DCs were obtained from an HLA-A*0201 donor and monocytes were purified by anti-CD14 magnetic separation as described under methods. For DC/Apo-Nec cells different time points after co-culture were studied. Results are the mean of triplicate determinations. (C) Expression of HLA-A*0201 in MART-1+ cell line (Mel-XY3) at different times after γ irradiation and culture was measured as described under Methods.