GS-9620 induces phosphorylation of NF-κB and Akt in pDCs.

PBMC isolated from healthy donors were cultured with GS-9620, resiquimod, or DMSO control. Phosphorylation of NF-κB and Akt was assessed in gated pDC and mDC subsets. (a) Flow cytometric histogram of p-NF-κB (using a phosho NF-κB (S529) specific antibody) following 30min stimulation (left panel) or p-Akt (using a phospho Akt (S473) specific antibody) following 60min stimulation (right panel) with 1μM GS-9620 (blue histogram) or DMSO control (grey histogram). (b) Fold increase in mean fluorescence intensity (MFI) of pDCs for pNF-κB (left panel) or p-Akt (right panel) after stimulation with 1μM GS-9620 normalized to DMSO control treatment. Statistically significant differences relative to DMSO control (p<0.05) are observed with GS-9620 stimulation for all assessed time points (p-NF-κB), and for 10, 15, 30, and 60min time points (p-Akt). (c) Fold increase in MFI upon stimulation with 1μM GS-9620 or resiquimod (R848) normalized to DMSO control treatment in mDCs or pDCs. As expected, phospho-responses to GS-9620 and R848 for both readouts, p-NF-κB and p-Akt, were significantly stronger in pDC compared to donor-matched mDC (p<0.01 for all comparisons). Graphs show data obtained from 6 (p-NF-κB) and 4 (p-Akt) independent healthy donors with mean ±SEM (bars).