peripheral blood mononuclear cells
mesenchymal stromal cells from adipose tissue
human fetal fibroblasts
low oxygen tension
E.R. Andreeva, O.V. Grigorieva, I.V. Andrianova, A.N. Gornostaeva, L.B. Buravkova
Stromal cells of mesenchymal origin such as fibroblasts (FB) and multipotent mesenchymal stromal cells (MMSC), play an important role of physiological microenvironment in various tissue compartments, modifying some properties of other cell types. The goal of this study was to compare immunomodulatory properties of two of stromal cell types: the MMSC and human fetal FB. We also evaluated the effects of reduced oxygen tension in culture medium on the stromal/immune cells interaction outcome.
Mononuclear cells (MNCs) were isolated from peripheral blood of healthy volunteers on Ficoll-Histopaque as described elsewere. MMSC from stromal-vascular fraction of human adipose tissue and human fetal fibroblasts (fFB) were cultured under 20% O2 and 5% O2. Immunophenotype of stromal cells was assessed by using antibodies against: CD13, CD29, CD34, CD44, CD45, CD54, CD90, CD105, CD106, CD117 (c-kit), HLA-ABC and vimentin. PHA-activated MNCs were cocultured with stromal cells during 72 hours and then cells carrying antigens CD3, CD19, CD16, CD56, CD25, HLA-DR were determined in MNC suspension.
Comparative immunophenotype analysis revealed that MMSCs and fFB were СD90+, СD105+, HLA-ABC+, СD34-, СD45-, HLA-DR- regardless of О2 concentration. The ratio of T-cells in suspension after cocoulture with stromal cells was practically unchanged. The share of B- and ТK-cells was increased. The share of CD3+/HLA-DR+ cells was decreased while coculturing both with MMSCs and fFB. In 5% O2 this reduction was statistically significant in compare with 20% O2 (p<0,05). CD3+/CD25+ cells decreased after coculture with stromal cells in 20% O2, in 5%O2 this affect was revealed only for MMSCs coculture.
Thus, it have been demonstrated that the MMSCs from the stromal-vascular fraction of human adipose tissue and human fFB have immunomodulatory potency, but the manifestation of immunosuppressive effects may vary depending on the cell type. For example, the fact that the MMSCs can inhibit the expression of early and late T-cell activation markers, and fFB – mostly late, may affect the immune response during the allogeneic stromal cells administration. In addition, the partial pressure of oxygen is an important microenvironmental factor, further modifying the result of cell-cell interactions that should be considered while developing approaches for stromal cells application for regenerative medicine needs.