Fig. 3

The immunosuppressive effects of f-LSCs is not mediated by apoptotic mechanisms. a AO/EB staining was performed as described in the Methods section on healthy PBMCs. The experiments included the following conditions: fresh unstimulated peripheral blood mononuclear cells (PBMCs), activated for 72 h with anti-CD3 mAbs, after coculture with fibroblast-like limbal stem cells (f-LSCs), and in the transwell system for the same time lapse. No typical signs of apoptotic event were observed under all four conditions. Original magnification: 40×. All pictures are representative of five independent experiments. b Active caspase-3 was detected by FACS showing a very faint involvement of apoptotic cascade in activated healthy PBMCs after 72 h of coculture with f-LSCs. FACS plots are representative of five experiments of identical design