Murine and human MSCs exhibit an immunosuppressive effect bypassing the species barrier. Responding BALB/c splenocytes (105 cells) were incubated for 4 days with 105 mitomycin-treated stimulator cells, in the presence or absence of MSCs (105 cells). The relative proliferative response corresponding to the mean cpm of a responder-stimulator pair in the absence of MSCs is attributed a 100% value ± SD. (A) C3 MSCs repress the proliferation of murine T lymphocytes independently of the haplotype of the stimulator splenocytes. Allogeneic stimulator splenocytes originated from 9 various mouse strains. (B) C3 MSCs inhibit murine T-cell proliferation induced by xenogeneic human peripheral blood mononuclear cells (hPBMCs). MSCs suppressed the proliferative response induced by 2 different sources of hPBMCs or allogeneic splenocytes. (C) MSCs from various species suppress the proliferative response to allogeneic stimulation. The response of murine T lymphocytes to allogeneic C3H and DBA1 splenocytes was inhibited in the presence of MSC lines (C3 and C9 cells), and primary mMSCs or hMSCs from 2 and 4 different samples, respectively.
