Alterations of Multipotent Mesenchymal Stromal Cells Induced by Interaction with Allogeneic Lymphocytes In Vitro

Multipotent mesenchymal stromal cells (MSCs) are widely used for cell therapy. Treatment with interferon-γ (IFNγ) increases the immunomodulating properties of MSCs. When administered intravenously, MSCs interact with lymphocytes. It is impossible to follow the fate of MSCs in the recipient organism. The aim of this study was to investigate the properties of MSCs after their interaction with lymphocytes in vitro. Bone marrow MSCs were co-cultured for 4 days with activated and non-activated lymphocytes. A portion of the MSCs was pretreated with IFNγ. HLA-DR expression on the MSCs increased when these cells were co-cultured with lymphocytes and after they were treated with IFNγ. The activated lymphocytes induced significantly higher HLA-DR expression levels than did IFNγ treatment. IFNγ increased the viability of MSCs when these cells were co-cultured with lymphocytes. The immunomodulating properties of MSCs were amplified after IFNγ priming and co-cultivation with lymphocytes; therefore, this amplification was not dependent on the IFNγ source. IFNγ treatment and lymphocyte interactions induced increases in the relative expression levels (RELs) of ICAM1 and factors involved in immunomodulation in the MSCs. IFNγ stabilizes MSCs while maintaining their viability. The data suggest that MSCs obtained from the hematopoietic cells donor or autologous should be used for cell therapy