Mesenchymal stem cells (MSCs), which evoke only minimal immune reactivity, may have
anti-inflammatory and immunomodulatory effects. In this study, we conducted a comparative
analysis of the immunomodulatory properties of MSCs derived from adult human tissues
including bone marrow (BM), adipose tissues (AT), umbilical cord blood (CB), and cord
Wharton's jelly (WJ). Using a multiple cytokine detection assay, we showed that there
were no significant differences in levels of secreted factors from non-stimulated
MSCs. We compared the immunosuppressive effect of BM-MSCs, AT-MSCs, CB-MSCs, and WJ-MSCs
on phytohemagglutinin-induced T-cell proliferation. AT-MSCs, CB-MSCs, and WJ-MSCs
effectively suppressed mitogen-induced T-cell proliferation as effectively as did
BM-MSCs. Levels of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha secreted
from activated T-cells increased over time, but these levels were significantly reduced
when cocultured with each type of MSCs. In addition, the expression of hepatocyte
growth factor, IL-10, transforming growth factor-beta(1), cyclooxygenase (COX)-1,
and COX-2 were unchanged in MSCs treated with IFN-gamma and/or TNF-alpha, while indoleamine
2,3-dioxygenase (IDO) expression increased. IFN-gamma and/or TNF-alpha produced by
activated T-cells were correlated with induction of IDO expression by MSCs, which,
in turn, suppressed T-cell proliferation. These findings suggest that MSCs derived
from AT, CB, or WJ could be substituted for BM-MSCs for treatment of allogeneic conflicts.