Fig. 6.

Effects of bortezomib on IFN-α-induced signal transduction in PBMCs. a The effects of IFN-α (10⁴ U/ml), bortezomib (10–20 nM; B = Bortezomib), or both agents combined were evaluated in PBMCs from healthy adult donors at 48 h post-treatment by annexin V/propidium iodide staining and flow cytometric analysis. Data are presented as the percentage of viable PBMCs. b Phosphorylation of STAT1 at Tyr⁷⁰¹ (P-STAT1) was measured in PBMCs by flow cytometry following a 18-h pre-treatment with bortezomib (10 nM) and a subsequent 15 min pulse-stimulation with IFN-α. Cells were placed in cytokine-free media and harvested for staining at various time points following IFN-α stimulation. Data are presented as the percentage of cells staining positive for P-STAT1. Voltage was set using an isotype control antibody and a minimum of 10,000 gated events were collected for each condition. Similar results were obtained upon co-treatment of PBMCs with bortezomib and IFN-α (data not shown)