Cytokine production in DC co-incubated with TCLs and from CTL co-cultured with DC incubated with TCLs. A: TNF-α and IL-6 levels were determined in cell culture supernatants by ELISA. Culture was performed in 96 well plates. Immature DC were incubated for 1 day with untreated SK29-Mel-1 or H-1PV-infected SK29-Mel-1 cells 10 days p.i. (MOI = 20 PFU/cell). Controls included mature or immature DC alone and untreated SK29-Mel-1 cells or lysates in a ratio 1:10. B: CTL were co-cultured for 1 day in a 96-well plate either with lysate-incubated DC, DC alone, or lysates alone at a ratio of 1:10. Concentrations of TNF-α and IL-6 were determined in supernatants by ELISA.