Effect Of Dendritic Cells Loaded With Parvovirus Infected Tumor Cell Lysate On T Cell Proliferation

Objective: TCL and PV-TCL loaded DCs respectively and to detect the surface phenotype of different groups of DCs,according to different antigen load of DCs,it was divided into unloaded DCs group,TCL-DCs group and PV-TCL-DCs group,by detecting the expression of PD-L1 and the ability to promote T cell proliferation and the secretion of IFN-? and IL-2.The effects of different antigenloaded DCs on T cell proliferation were compared and analyzed,which provided reference for clinical application of DCs immunotherapy.Methods: DCs was induced by tumor patient PBMCs,and the cell morphology of DCs was observed by light microscopy.Human lung adenocarcinoma A549 cells were repeatedly frozen and thawed five times to obtain TCL.Human lung adenocarcinoma A549 cells were co-cultured with PV and then subjected to frozen and thawed five times to obtain PV-infected TCL(PV-TCL),using TCL and PV-TCL loads DCs respectively.DCs were divided into DCs group,TCLDCs group and PV-TCL-DCs group according to DCs antigen load.The surface phenotype and PD-L1 expression of different groups of DCs were determined by flow cytometry.Autologous T cells were co-cultured with different groups of DCs to determine the proliferation of T cells and the ability to secrete IFN-? and IL-2.Results:(1)Under the light microscope,DCs induced by PBMCs from tumor patients were observed,and there were many dendrites on the surface of the cell membrane,which is a typical morphological feature of DCs.Flow cytometry detected high levels of DCs expression in HLA-DR,moderate levels of CD1 a,CD80 and CD86 expression,and low levels of CD83 and CD14 expression.(2)The surface markers of three groups of DCs were detected by flow cytometry,compared with TCL-DCs group and unloaded DCs group,CD80,CD83 and CD86 in PV-TCL-DCs group showed significant increase in markers of DCs maturity(respectively P < 0.01,P < 0.001 and P < 0.01).This indicates that PV-TCL-DCs is more mature than TCL-DCs.(3)The surface markers of three groups of DCs were detected by flow cytometry.The expression of PD-L1 was increased in PV-TCL-DCs compared with TCL-DCs group(P = 0.002)and unloaded DCs group(P = 0.000),which further confirmed PV-TCL-DCs are more mature than TCL-DCs.(4)After co-culture of three groups of DCs with autologous T cells,PVTCL-DCs can significantly promote autologous T cell proliferation compared with T cells alone.(5)Compared with the TCL-DCs group and the unloaded DCs group,the PV-TCL-DCs group significantly enhanced the secretion of IFN-? and IL-2 by a autologous CD4 + and CD8 + T cells(P < 0.05).Increased secretion of IFN-? and IL-2 by T cells indicates that PV-TCL-DCs can effectively activate CD4 + and CD8 + T cells.Conclusions:(1)PV-infected TCL-loaded DCs can increase the expression of CD80,CD83,and CD86,and promote the maturation of DCs.(2)PV-infected TCL-loaded DCs can express higher levels of PD-L1.(3)PV-infected TCL-loaded DCs co-culture with autologous T cells can promote T cell proliferation and the secretion of IFN-? and IL-2.