Negatively regulatory effects of bone marrow-derived mesenchymal stem cells supernatant on allogeneic lymphocytes proliferation / 中国组织工程研究

ABSTRACT

BACKGROUND: Preliminary study has proven that adult human bone marrow-derived mesenchymal stem cells (MSCs) suppress peripheral blood lymphocytes proliferation.But the mechanism was still to be investigated.OBJECTIVE: To study the negatively regulatory effect of adult human MSCs on allogeneic lymphocyte proliferation by cell-free condition.DESIGN,TIME AND SETTING: Cytological observation in vitro,which was performed in the Lanzhou General Hospital,Lanzhou Military Area Command of Chinese PLA between October 2005 and December 2007.MATERIALS The bone marrow sample was provided by the allo-transplantation donor.The peripheral blood lymphocytes were provided by the healthy volunteer.METHODS: Adult human MSCs were separated with Percoll + adherence method.Allogeneic peripheral blood lymphocytes were obtained from healthy donors with Ficoll solution and the cell concentration was adjusted as 2×109/L for use.100μ L MSCs culture supernatant was taken out in 96-well plates.The groups were following A superuatant + 3-day MSCs culture media (100 μ L/well); B superuatant + phytohemagglutini (PHA; 1 g/L,5 μ L); C medium + LG-DMEM culture media containing 10% fetal bovine serum (100 μ L); D medium + PHA (1 g/L,5 μ L).The cells were incubated at 37 ℃ with 5% CO2 in a fully humidified atmosphere for three days.MAIN OUTCOME MEASURES: Effect of MSCs supematant on proliferation and transformation of variant lymphocytes.RESULTS: Peripheral blood lymphocytes proliferation was suppressed as compared with the blank control group and PHA group after MSCs culture,and the inhibition ratio was 9.00% (P ＜ 0.05).When lymphocytes were stimulated by PHA,the suppression effects were even stronger and the inhibition ratio was 20.91% (P ＜ 0.01).CONCLUSION: Adult human MSCs supernatant can suppress peripheral blood lymphocytes proliferation and transformation; furthermore,PHA can enhance the inhibitory effect,suggesting the negative regulation is at least in part due to indirectly inhibiting lymphocytes via soluble cytokines.