Immunomodulation Assays with T Cells and MSCs

Immunomodulation assays were performed as previously described [14 (link)]. Briefly, peripheral blood mononuclear cells (PBMC) were obtained by Ficoll-Hypaque gradient centrifugation of peripheral blood from healthy donors with informed consent. Purification of T lymphocytes (>95% purity) was performed by positive selection using the MACS system (Miltenyi Biotec). A cocktail of phytohemagglutinin (PHA, 5 μg/mL; Remel Europe, Kent, UK) and interleukin-2 (IL-2, 20 U/mL; Biotest AG, Dreieich, Germany) was used to activate T lymphocytes. Activated T cells and stimulated or unstimulated FSK-MSCs were plated in cocultures at both cell ratios: 1/80 and 1/5 for 5 days.