Changing the Properties of Multipotent Mesenchymal Stromal Cells by IFNγ Administration

We studied changes in the population of human multipotent mesenchymal stromal cells activated by IFN.. The cells were cultured under standard conditions; IFN. was added in various concentrations for 4 h or over 2 passages. It was shown that the total cell production significantly decreased after long-term culturing with IFN., but 4-h exposure did not affect this parameter. After 4-h culturing, the expression levels of IDO1, CSF1, and IL-6 increased by 300, 7, and 2.4 times, respectively, and this increase persisted 1 and 2 days after removal of IFN. from the culture medium. The expression of class I and II MHC (HLA) on cell surface practically did not change immediately after exposure to IFN., but during further culturing, HLA-ABC (MHC I) and HLA-DR (MHC II) expression significantly increased, which abolished the immune privilege in these cells, the property allowing clinical use of allogenic multipotent mesenchymal stromal cells. Multipotent mesenchymal stromal cells can suppress proliferation of lymphocytes. The degree of this suppression depends on individual properties of multipotent mesenchymal stromal cell donor. Treatment with IFN. did not significantly affect the intensity of inhibition of lymphocyte proliferation by these cells.