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 IFNγ. The cells were cultured under standard conditions; IFNγ 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 IFNγ, 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 IFNγ from the culture medium. The expression of class I and II MHC (HLA) on cell surface practically did not change immediately after exposure to IFNγ, 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 IFNγ did not significantly affect the intensity of inhibition of lymphocyte proliferation by these cells.

[Characteristics of stromal cell precursors in patients after allogeneic bone marrow transplantation].

UNLABELLED: AIM. To study the elements of the mesenchymal stromal cell compartment (multipotent mesenchymal stromal cells (MMSCs)) and their more mature progenies of fibroblast colony-forming units (CFU-F) in patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). SUBJECTS AND METHODS. The total production of MMSCs after 5 passages, the time of their growth, and the concentration of CFU-F in the bone marrow from patients were determined using the control sections before transplantation and over time for 2 years after allo-HSCT. What is more, the genetic affiliation of the MMSCs from the patients after allo-HSCT and their immunophenotype were studied. RESULTS: The MMSCs from the patients after allo-HSCT belong to a recipient and have the immunophenotype that meets the international standard for these cells. The total production of MMSCs in the cultures obtained from the bone marrow of the patients with hematologic diseases was decreased. Not all the samples from the patients after allo-HSCT are able to undergo 5 passages. In addition, the time of growth substantially increases and the total production of cells decreases in all the analyzed cultures. These indicators are gradually restored; however, they never achieve the mean values in donors. The concentration of CFU-F in the bone marrow from the patients are reduced as compared to that in the donors prior to transplantation and decreased still further after allo-HSCT. These cell precursors are not restored for at least 2 years following allo-HSCT. CONCLUSION. Both examined categories of the cell precursors of the stromal environment suffer from both the disease itself and allo-HSCT in the patients with hematologic diseases.