Inflammatory Stimuli Effects on hPDLSCs

24 h after seeding an appropriate number of hPDLSCs in 6-well plates, these cells were stimulated with either 5 ng/ml IL-1β [18 (link)] or 10 ng/ml TNF-α [20 (link)] or 100 ng/ml IFN-γ [21 (link)] (all from Invivogen, San Diego, USA) in FBS-free DMEM for all performed experiments. After 48 h incubation, hPDLSCs were proceeded as indicated below. hPDLSCs were additionally treated with either 50 µM PF-06840003 (IDO-1 inhibitor) or 1 µM BMS202 (PD-1/PD-L1 inhibitor) [22 (link)] or 1 µM Celecoxib (PTGS-2 inhibitor) [23 (link)] before and during indirect co-culture (all from Selleck Chemicals, Houston, USA). PF-06840003 concentration was chosen due to its effect on IDO-1 enzymatic activity in hPDLSCs, presented in Figure S1.