Comparison of immunomodulatory properties of exosomes derived from bone marrow mesenchymal stem cells and dental pulp stem cells.

Substantial discoveries suggested that exosomes released from multiple sources of stem cells can affect the biological functions of target cells. In present period, the immunosuppressive properties of exosomes derived from bone marrow mesenchymal stem cells (BMMSCs-E) have been extensively recognized, but few studies have been reported about exosomes secreted from dental pulp stem cells (DPSCs-E) in the field of medical immunity. Hence, the aim of this study is to compare the immunomodulatory capacity of BMMSCs-E and DPSCs-E. Peripheral blood mononuclear cells (PBMCs) were co-cultured with them respectively and the proportion of regulatory T cells (Treg) was detected to increase. Subsequently, we stimulated CD4+T cells with BMMSCs-E and DPSCs-E to observe their effects on the polarizations, chemokines secretion, apoptosis, and proliferation of CD4+T cells. We found that DPSCs-E inhibited the differentiation of CD4+T cells into T helper 17 cells (Th17) and reduced the secretions of pro-inflammatory factors IL-17 and TNF-α, while promoted the polarization of CD4+T cells into Treg and increased the release of anti-inflammatory factors IL-10 and TGF-β. What's more, these capabilities of DPSCs-E were stronger than those of BMMSCs-E. In addition, DPSCs-E were more effective in inducing apoptosis of CD4+T cells compared with BMMSCs-E, and DPSCs-E inhibited the proliferation of CD4+T cells, which is similar to BMMSCs-E. We draw a conclusion that DPSCs-E have stronger immune-modulating activities than BMMSCs-E, and may be a new therapeutic tool for the treatment of immunological diseases.