Effect Of Jagged-1 On The Immunotolerance Induced By Dendritic Cell-mediated T Cells

Objective:To investigate the effects of Jagged-1 on the skin allograft immunotolerance induced by dendritic cell-mediated T cells and its mechanism.Methods:A model of inducing bone marrow DCs of mice in vitro was established to observe the effects of Jagged-1 on the morphology of DCs co-induced by granulocyte-macrophage colony stimulating factor(rmGM-CSF) and recombinant murine interleukin 4(rmIL-4);Both fluorescin-conjugated monoclonal antibody labeling technique and flow cytometry were used to evaluate expression of differentiation mark CD11c and mature mark MHC-â…¡,CD86,CD80,CD40 on the DCs induced by Jagged-1;The stimulating capacity of Jagged-1-induced DCs,T cells and T cells from the DC-T co-culture system for allogeneic lymphocytes was evaluated by MTT assay.The expression of interleukin 10(IL-10),interleukin 2(IL-2),interleukin 4(IL-4),transforming growth factorβ(TGF-β),interferon-gamma(IFN-γ),tumor necrosis factorα(TNF-α) in supernatant of DCs,T cells and the DC-T cells co-culture system induced by Jagged-1 were detected by Luminex technique and enzyme-labeled immunosorbent assay(ELISA);A model of allogeneic skin transplantation in mice was established to observe the effects of Jagged-1 on survival time of transplanted skin,skin graft pathological change,delayed type hypersensitivity (DTH),the reactivity of the lymphocytes in mice after skin transplantation and the percentage of the expression level of CD4⁺CD25⁺Treg in recipient peripheral blood.Results:The typical morphous of mature DCs was observed in cells cultured with Jagged-1.The mean fluorescence intensity(MFI) of CD11c on cells treated with Jagged-1 was enhanced after 6 d or 12 d in culture(P＜0.01 or P＜0.05).Jagged-1 also increased the proportion of CD80,CD40 and MHC-â…¡^high cells in culture and up-regulated MFI of CD80 and CD40(P＜0.01),and it had no effect on MFI of CD86.Compared with control,the amount of TGF-β,IL-6,IL-4 or IL-10 expression of Jagged-1-induced DCs,T cells and T cells from the DC-T cells co-culture system increased significantly and the amount of IFN-γ,IL-2,IL-12 and TNF-αexpression decreased markedly(P＜0.01).The mixed lymphocyte reaction(MLR) revealed that Jagged-1-induced DCs, T cells and T cells from the DC-T cells co-culture system had the weakest ability to activate allogeneic lymphocytes,and DAPT can reverse the effect of Jagged-1 partly.The average survival time of skin graft in Jagged-1 group was 38.6 d,which was significantly prolonged compared with control group and Jagged-1 plus DAPT group(P＜0.01).The inflammatory cells of Jagged-1 group in the skin graft were significantly reduced.The recipient lymphocytes of the Jagged-1 group appeared hyporesponsiveness to the donor lymphocytes(P＜0.01),but hyperresponsiveness to KM mice in MLR.They were showed distinguished hyporesponsiveness also in DTH(P＜0.01).Compared with control group and Jagged-1 plus DAPT group,the mouse peripheral blood of Jagged-1 group could be upregulated the level of CD4⁺CD25⁺Treg(P＜0.01 or P＜0.05),which could be reversed by DAPT.Conclusion:The results suggest that Jagged-1 may induce the differentiation and maturity of DCs from bone marrow.Jagged-1-induced DCs prime naive T cells to the Th2 cells by inhibited the expression of IFN-γ,IL-12,TNF-αand enhanced the expression of IL-4,IL-10,moreover,Jagged-1 weaken the the activation capacity of DCs for lymphocytes;the CD4⁺T cells treated by Jagged-1 combined with dendritic cells can induce recipients to obtain immunotolerance of donor antigenic specificity,which concernes the relative quantity of CD4⁺CD25⁺Treg and the polarization of the Th1/Th2 cytokines.They may provide a new treatment target for the clinical application in transplantation tolerance.