The induction of tolerogenic dendritic cells by curcumin and its mechanism / 中华器官移植杂志

ABSTRACT

Objective To observe the induction of tolerogenic dendritic cells (DCs) by curcumin (Cur) and its mechanism.Methods After immature DCs from bone marrow cells of Wistar rats were treated with different concentrations of Cur (0,10,20 and 30?mol/L) respectively,and then the DCs were tested by flow cytometry for the surface molecules expression.After the immature DCs were treated by 30?mol/L Cur with or without stimulation of LPS,endocytosis of DCs to dextran was tested by flow cytometry.The production of IL-12 in DC culture supernatant was determined by ELISA.The levels of NF-?B p65 and RelB translocation to the nucleus were investigated by Western- blot.The activity of NF-?B was detected by NF-?B-binding ELISA and luciferase reporter gene analy- sis.The ability of DCs to stimulate the proliferation of T cells from Lewis rats were analyzed by mixed leukocyte reactions (MLR).Results Cur suppressed LPS-indueed cell-surface expression of costimu- latory molecules (CD80,CD86 and CD40) in a dose-dependent manner.When Cur was used at a con- centration of 30?mol/L,there was no marked difference in the surface molecules expression of LPS- inducing DCs as compared with immature DCs.After DCs were induced by LPS (LPS group),the positive rate of FITC-Dextran uptake was (36.6?7.2)%,and the secretory amounts of IL-12 were (415.9?42.7) pg/ml.In DCs of LPS group,the intranuclear RelB and p65 were highly expressed and their DNA binding activity was 0.65?0.08 and 0.74?0.07 respectively.The luciferase activity of reporter gene in LPS group DCs was remarkably increased to 435% as compared with that in the controls.DCs in LPS group showed strong capacity to stimulate T cells proliferation.When DCs were treated with 30?mol/L Cur followed by induction with LPS (Cur+LPS group),the positive rate of Dextran uptake was (78.6?14.2)% and remarkably higher than in LPS group (P