Fig. 2.

Effect of oAECs, at different culture passages (P1 vs P3), on the PHA-stimulated lymphocyte proliferation. “Early” and “late” oAECs were used at passage 1 (P1; dark grey bars) or at passage 3 (P3; light grey bars) of culture and were seeded in contact with PBMNCs (panels a and b) or in a transwell system (panels c and d). oAECs were added to obtain different PBMNC:oAEC ratios (1:1, 1:0.5, 1:0.25, 1:0.125, and 0.0625). Data are represented as mean and SD. The number of the independent experiments performed is indicated inside the bars. * = p < 0.05, ** = p < 0.01; oAECs at Passage 1 (P1) versus oAECs at Passage 3 (P3). ⁺ = p < 0.05, ⁺⁺ = p < 0.01; ⁺⁺⁺ = p < 0.001 versus PHA-stimulated PBMNCs (in absence of oAECs)