Effects of hypoxic umbilical cord-derived mesenchymal stem cells on the immune response of umbilical cord blood CD34~+ cells

Objective:To investigate the effect of hypoxic umbilical cord-derived mesenchymal stem cells (UC-MSCs) on the immune responses of umbilical cord blood (UCB)CD34+ progenitor cells,and the secretion of immunomodulattory cytokines.Methods:UC-MSCs were isolated and cultured,the growth morphology were observed.Surface markers of UC-MSCs were detected by flow cytometry.The hypoxic and non-hypoxic UC-MSCs were added to the co-culture system of UCB CD34+ progenitor cells and peripheral blood mononuclear cells (PBMC),after culturing for 96 h,the supernatant were collected and IFN-γ and IL-10 were detected by ELISA.Results:UC-MSCs did not express CD40,CD80,CD86,HLA-DR,CD34.The hypoxic UC-MSCs could inhibit the secretion of IFN-γ (compared with controls,P 0.05),while enhanced the secretion of IL-10 (compared with controls,P 0.05),however,compared with non-hypoxia group,the secretion of IFN-γ increased,IL-10 decreased.Conclusion:Hypoxic UC-MSCs can inhibit the immune responses of UCB CD34+ progenitor cells,promote the secretion of IL-10,inhibit the secretion of IFN-γ,however,the effects decrease compared with normoxia UC-MSCs.