Aim: To obtain fetal mesenchymal stem cells isolated from human placental tissue (hfPMSCs) and study the effects of IFN-γ on immunomodulatory property of hfPMSCs in vitro.
Methods: hfPMSCs were isolated from the fetal side of human placentas by enzyme digestion. Expressions of cell surface antigens CD73, CD90, CD105, CD14, CD34, CD45 and HLA-DR were tested by flow cytometry. The fetal origin of the placental cells was verified by DNA identity test using four known short tandem repeat (STR) polymorphic markers D2S1399, D10S2325, D18S535 and GATA198B05. After hfPMSCs were treated with 10 ng/mL IFN-γ, the expressions of IL-6, IL-8, IL-10 and HGF at both mRNA and protein levels were measured using quantitative real-time PCR (q-PCR) and ELISA. The expressions in controls without IFN-γ treatment were examined in the same way.
Results: The isolated cells expressed MSCs surface markers CD73, CD90 and CD105, but did not express CD14, CD34, CD45 and HLA-DR. For all the STR markers tested, the MSCs from the fetal side of the placenta carried the alleles of both maternal and paternal origin, indicative of the fetal genome. q-PCR indicated that the expression of IL6 mRNA in IFN-γ treated group was significantly higher than those in the control group (P<0.05), whereas the levels of IL-10 and HGF mRNA were down-regulated by IFN-γ treatment (P<0.05). ELISA revealed that IFN-γ treated group expressed strikingly the higher level of IL-6 protein compared with the control group (P<0.05), and the lower levels of IL-8, IL-10 and HGF (P<0.05).
Conclusion: The method used in the study can obtain hfPMSCs from human placenta tissues, and IFN-γ has a negative effect on immune suppression function of the hfPMSCs.