IL-12 and TNF-α secretion by DCs are modulated by bortezomib. (A-B) Adherent monocytes cultured in the presence of GM-CSF and IL-4 for 6 days were stimulated with or without bortezomib at the indicated concentrations (in ng/mL) for 24 hours. LPS (100 ng/mL) was added during the last 16 hours of incubation. Supernatants were subsequently collected, and IL-12 (A) and TNF-α (B) were determined by commercially available ELISAs.