Aim: To compare and study the inhibitory effects of human bone marrow mesenchymal stem cells (HBMSCs) and human palacenta mesenchymal stem cells (HPMSCs) on T cell proliferation, and the underlying mechanism.
Methods: The expression of B7H4 on HBMSCs or the expression of PDL1 on HPMSCs were detected by FCM. Blocking experiment was used to analyze the effects of B7H4 or PDL1 on HBMSCs or HPMSCs mediating suppression on T cell proliferation and cell cycle.
Results: FCM detection showed that HBMSCs highly expressed B7H4, while HPMSCs highly expressed PDL1, the negative immune molecules. Blockade B7H4 on HBMSCs with B7H4mAb significantly attenuated the inhibitory effects of HBMSCs on T cell proliferation. Likewise, blocking the expression of PDL1 on HPMSCs obviously weakened the suppressive effects of HPMSCs on T cell proliferation activated by PHA. Moreover, Blockade B7H4 on HBMSCs with B7H4mAb or PDL1 on HPMSCs with PDL1mAb significantly weakened the inhibitory effects of HBMSCs or HPMSCs on T cell cycle through down-regulating the cell number in G(0);/G(1); phase and up-regulating the cell number in S phase.
Conclusion: HBMSCs and HPMSCs could mediate the suppressive effects on T cell proliferation through expressing different negative immune molecules.