Immunosuppressive action of Stro-1~+ and Stro-1~- subgroups of human mesenchymal stem cells / 解放军医学杂志

ABSTRACT

Objective To explore the difference of immunosuppresive effect between the expanded Stro-1+ and Stro-1-subgroups of human mesenchymal stem cells in vitro. Methods Mononuclear cells (MNCs) were isolated from bone marrow (BM) samples and seeded in a T-75 cm2 tissue culture flask contained with Dexter medium. When 50% confluence was obtained, adherent cells were collected and incubated with anti-stro-1 antibody, and the Stro-1+ and Stro-1-MSCs were further seeded for expansion. The total culture time (median) was 15 days. Cells were then analyzed by flow cytometry. One-way mix lymphocyte reaction (MLR) (1?105 responding cells and an equal number of stimulating cells/well were co-cultured in 96-well plates) and nonspecific mitogenic stimuli phytohemagglutinin (PHA) plus interleukin-2 (IL-2) induced lymphocytes proliferation (PBL 1?105/well were mixed with PHA 10?g/ml and IL-2 500U/ml in 96-well culture plates) were established in vitro. 1?103-3?104 irradiated Stro-1+ MSCs and Stro-1-MSCs were added into the two systems at the beginning of reaction. Immunosuppressive actions of both Stro-1+ or Stro-1-MSCs were compared. Results Adherent cells contained a median of 9% (range 5%-26%) Stro-1+ cells, which expressed higher immunophenotype of MSCs. In both reaction systems, suppressive actions occurred in a dose-dependent fashion when whatever Stro-1+ MSC or Stro-1-MSC were added. However, that the addition of 1?103 Stro-1-cells enhanced rather than inhibited the lymphocyte proliferation in one-way MLR. In the presence of various concentrations of MSCs, Stro-1+ MSCs always showed a significantly increased inhibitory effects in comparison to Stro-1-MSCs (P