ABSTRACT
Objective To investigate the effect of programmed death ligand 2 (PDL2) in human placenta derived mesenchymal stem cells(hPMSCs) mediated immunoregulation on peripheral blood T cells activation,proliferation and cell cycle.Methods The expression of the PDL2 on hPMSCs was detected by RT-PCR,LSCM and FCM,respectively.Specific PDL2 siRNAs were transfected into hPMSCs via cathodolyte liposome transfection method.T cells were sorted from healthy peripheral blood by gradient centrifugation.The expression of early activation phenotype,proliferation and cell cycle of T cells were analyzed by FCM.Results PDL2 siRNA could effectively block the expression of PDL2 which was highly expressed on hPMSCs.The expression of CD69 on T cells had no significantly difference in blocking groups compared with unblocking groups.hPMSCs could inhibit the proliferation of T cells induced by PMA,compared with that of unblocking groups,the number of the T cells in G0/G1 phase was decreased while the number of the T cells in S phase was increased in the blocking groups.Conclusion PDL2 expressed on hPMSCs could promote the inhibitory effect of hPMSCs on T cell cycle and proliferation.