Endogenous MP presentation. Immature HLA A^*0201⁺ DCs were infected with Vac-ctr or Vac-MP and treated simultaneously with cathepsin D (1 μM), pepstatin A (200 μM) or NH₄Cl (50 μM), brefeldin A (1 μg/mL), lactacystin (40 μM), or were previously infected with Vac-ctr or Vac-ICP47 (MOI 2). Noninfected DCs were incubated with MP peptide (100 nM) and the same dose of inhibitors. A maturation stimulus was given in the beginning of the incubation. All DC groups were fixed in glutaraldehyde and cultured with Flu16. Responses were assessed by IFN-γ ELISPOT. The left axis shows endogenous presentation and the right synthetic peptide presentation. One representative set of experiments of 3 is shown.