Study of the immunomodulatory effects of osteogenic differentiated human dental pulp stem cells

Dental pulp stem cells (DPSC) are promising tools in regenerative medicine due to their differentiation potential and immunomodulatory properties. However, it is not clearly known whether or not DPSCs maintain their immunosuppressive effects after differentiation. In the present study, we examined the immunomodulatory effects of osteogenic differentiated DPSCs (OD-DPSCs). OD-DPSCs and undifferentiated DPSCs were co-cultured with allogenic PBMCs in different ratios and the proliferation of the PBMCs was measured. The concentration of IL-10, TGF-β, PGE2, IL-6, and NO were then examined. Moreover, the expression of IDO, HLAG, and HGF genes were determined in undifferentiated and OD-DPSCs. The results showed that OD-DPSCs could inhibit the proliferation of allogenic PBMCs. The levels of PGE2, IL-6, and TGF-β anti-inflammatory cytokines increased after the co-culture. Moreover, the levels of NO increased during the differentiation process and the expression of IDO, HLAG, and HGF genes remained unchanged after osteogenic differentiation. Although, there were some differences between the OD-DPSCs and undifferentiated DPSCs in terms of their cytokine and NO production, undifferentiated DPSCs maintained their immunomodulatory activities upon differentiation.