Figure 5.
Immunoproteasome inhibition abrogates IFN-α production by human PBMCs. (a) Human PBMCs were incubated with titrating amounts of the indicated PIs in the presence of CpG2216 (250 ng/ml) or Poly- IC (100 mg/ml) overnight. IFN-α levels in the cell culture supernatants were measured by ELISA. Data are shown from a single donor and are representative of 5 independent experiments with different donors. (b) pDCs were purified from two different human donors, a healthy control and a hemachromatosis patient. Purity of >95% was confirmed by flow cytometry. Proteasome activity was measured as described using both an enzymatic activity assay and an active site ELISA. β5 and LMP7 containing 20S subunit was quantitated in ng/mg protein and expressed as a %total 20S, mean +/− SEM.