Human Bone Marrow Mesenchymal Stem/Stromal Cells Preserve Their Immunomodulatory and Chemotactic Properties When Expanded in a Human Plasma Derived Xeno-Free Medium

Figure 1

Immunomodulation by xeno-free MSC. (a) Analysis of the percentage of proliferative responder cells (PRC) present in a mixed leukocyte reaction (MLR) in the absence (continuous line) or in the presence of MSC (discontinuous line, indicated by “+MSC”). Representative comparative histograms (top) and bar graphs (bottom) of immunosuppression (i) and immunostimulation (ii) (, with 3 different hMSC donors; paired t-test). (b) Immunosuppression—proliferation of R cells was stimulated with PHA. (iii) Histograms show examples of hMSC immunosuppression (expanded in FBS- or XF-Medium). (iv) Summary of the collected data—the percentage of proliferative R is indicated (, with 3 different hMSC donors; paired t-test). (c) Immunostimulation—proliferation rate of resting PBMCs compared with the one obtained when coculturing the same cells with hMSC. (v) Histograms of these two conditions with hMSC expanded in FBS-Medium or XF-Medium. (vi) Summary of the collected data—the percentage of proliferative R is indicated (, with 3 different hMSC donors, paired t-test). (d) TNF-α production in different cultures. Supernatants of resting PBMCs (responder cells, R) or PBMCS stimulated with 5 μg/mL PHA (R + PHA) in coculture or not with hMSC were collected and analysed by ELISA. Assays were done in FBS-containing medium when hMSC were expanded in FBS-Medium or in SCC-containing medium for hMSC expanded in XF-Medium (MSC1: hMSC with immunostimulatory properties; MSC2: hMSC with immunosuppressive properties) (, Kruskal-Wallis test followed by Dunn’s multiple comparison test).

(a) Mixed leukocyte reaction

(b) PHA-stimulated PBMCs—immunosuppression

(c) Nonstimulated PBMCs—immunostimulation

(d) TNF-α