Mesenchymal stem cells modulate immune responses combined with cyclosporine in a rat renal transplantation model

Mesenchymal stem cells (MSCs) are pluripotent progenitors for a variety of cell types. Their down-regulation of the immune response in vivo has been hypothesized, but not yet substantiated, by experimental evidence. We investigated graft function, histology, animal survival days reverse transcriptase-polymerase chain reactor (RT-PCR) analysis of interleukin (IL)-1, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-beta 1. The results demonstrated that MSCs down-regulated immune responses, reduced production of some inflammatory mediators, preserved graft function in the initial stage after transplantation, and prolonged animal survival. However, the effects were not as strong as those of cyclosporine (CsA) therapy. Moreover, MSCs combined with low-dose CsA protected graft function, but could not prolong animal survival compared with CsA monotherapy, indicating a potential interaction between MSC and CsA activities, possibly allowing reduced CsA doses.