FIG. 2.

In vitro immunomodulatory effect of MSCs and MSC-derived MVs on T-cell proliferation. The graph shows the proliferation of healthy donor peripheral blood mononuclear cells (PBMCs) stimulated with phytohemagglutinin (PHA), in the presence or in the absence of either MSCs (with two different MSCs:PBMCs ratios 1:2 and 1:10) or MVs, isolated from MSCs with two different procedures (MVs-1 and MVs-2). Each bar represents the percentage of proliferation of 10⁵ PBMCs, calculated by measuring ³H-thymidine incorporation after 3-day co-culture. The counts per minute (cpm) values at each cell concentration were normalized to the cpm of PBMCs without MSCs or MVs in each experiment. Each bar represents the median±SD of 12 experiments (each point being in triplicate). P values lower than 0.01 (**) were considered highly statistically significant.