Figure 5: The proteasome inhibitor MG132 reverses the inhibitory effect of VISTA on TLR signaling.
(A) VISTA-expressing THP-1 cells (THP-1VISTA) and control cells (THP-1Ctrl) were pretreated with DMSO solvent control or MG132 (10 μg/mL) for 30 minutes prior to stimulation with Pam3Cys4 (10 μg/mL). Phosphorylation (p) of Jnk1/2, Erk1/2, TAK1, and IKKα/β were examined by Western blotting. The ratios of phosphorylated proteins to total protein were quantified using Image J software and shown numerically under each time point. (B) WT and Vsir−/− peritoneal macrophages (pooled from two-three mice of each genotype) were pretreated with DMSO or MG132 as in A before being stimulated with CpG (1 μg/mL). Total lysates were generated and analyzed as in A. Shown are representative results from three independent repeats.