Objective: To investigate the effect of mesenchymal stem cell (MSC) on naive T cell and to explore its mechanism of immunoregulation.
Methods: After culturing for 3 passages, MSC was incubated with naive T cells differentiated from cord blood CD34(+) cells in vitro. Variance of cytokine produced by naive T cell in culture supernatant was analyzed by enzyme-linked immunoassays.
Results: On the 7th day of co-culture, a mild proliferation of T cells in the co-culture group was observed: (9.15 +/- 0.68) x 10(5)/well in MSCs + naive T cells group versus (4.87 +/- 1.33) x 10(5)/well in naive T cells alone group (P < 0.05). IFN-gamma production was lower in MSCs + naive T cells group than that in naive T cells alone group: (1.147 +/- 0.181) pg/ml versus (4.897 +/- 0.189) pg/ml (P < 0.05), but IL-2 production was higher in the co-culture group: (16.141 +/- 2.729) pg/ml versus (2.551 +/- 0.460) pg/ml (P < 0.05). Neither IL-4 nor IL-10 were detected.
Conclusions: MSC have allogeneic effect on naive T cell, but may suppress alloreactive T lymphocyte and reduce the incidence of GVHD partly by decreased IFN-gamma production. The result may provide new clues for explaining immunoregulatory mechanism of MSC.