PGE2 Contributes to In vitro MSC‐Mediated Inhibition of Non‐Specific and Antigen‐Specific T Cell Proliferation in MS Patients

Current theories of multiple sclerosis (MS) induction and progression place autoreactive T cells in the focus of the pathogenesis. Mesenchymal/stromal stem cells (MSC) have become a promising alternative approach for pathogenic therapy of MS due to their immunomodulatory properties, underlying mechanisms of which are intensive study. The objective of the research was to investigate the contribution of PGE₂ to MSC‐mediated suppression in patients with MS using in vitro model of mitogen‐ and myelin‐stimulated T cell cocultivation with autologous/allogeneic MSC. We have showed that PGE₂ production depends on cell‐to‐cell contact of MSC and lymphocytes. The antigenic stimulation did not affect PGE₂ production following cocultivation of MSC and PBMC, and it is the presence of MSC in cell culture that significantly increases PGE₂ production irrespective of antigenic cultivation conditions. Simultaneously, PGE₂ synthesis correlated with indexes of MSC‐mediated suppression of mitogen‐ and myelin‐stimulated T cell proliferation in patients with MS. No significant differences in PGE₂ production by autologous and allogeneic MSC have been established. These results have demonstrated that in patients with MS, PGE₂ is one of the possible factors of MSC immunosuppression. The interrelation between PGE₂ concentrations and T cell proliferation suppression mediated by MSC may explain one of the immune mechanisms of cell therapy, which is crucial for the further proper use of MSC in MS research and pathogenic treatment.