未成熟树突状细胞对T细胞活化及其IFN-γ和IL-12表达的影响

Effect of immature dendritic cells on the activation of T cells and the expression of IFN-γ and IL-12 by T cells

目的:探讨未成熟树突状细胞(DC)对T细胞活化及其IFN-γ和IL-12表达的影响。方法:通过诱导Lewis大鼠骨髓前体细胞,获取未成熟(iDC)和成熟(mDC)两种状态的DC;将两种DC用乙酰胆碱受体(AChR)负载后进行T细胞重复刺激、交叉刺激和无关抗原刺激试验,观察T细胞增殖情况并测定T细胞IFN-γ、IL-12的表达水平。结果:(1)AChR负载的iDC可明显抑制T细胞增殖,且这种被抑制的T细胞对AChR负载的mDC的交叉刺激也不引起增殖,但对无关抗原OVA负载的mDC的刺激可产生明显增殖。(2)与mDC组比较,AChR负载的iDC初次和重复刺激均明显抑制T细胞IFN-γ和IL-12的表达。结论:iDC可诱导抗原特异性T细胞耐受,耐受机制可能与Th1细胞因子IFN-γ和IL-12的抑制有关。

Objective：To investigate the effect of immature dendritic cells（DCs） on the activation of T cells and the expression of IFN-γ and IL-12 by T cells.Methods：Immature and mature DCs（iDCs and mDCs） were induced from rat bone marrow precursor cells.After pulsed with acetylcholine receptor（AChR）,DCs were used to stimulate T cells by any stimulations of repetitive,cross or independent with antigen ovalbumin.The proliferation of T cells and the expression of IFN-γ and IL-12 by T cells were measured.Results：（1） The AChR pulsed iDCs inhibited the proliferation of T cells.The inhibited T cells eidn’t propagate when restimulated by AChR pulsed mDCs but propagate intensively when restimulated by ovalbumin pulsed mDCs.（2） Compared with the responses of mDCs,the expressions of IFN-γ and IL-12 by T cells stimulated with AChR-pulsed iDCs were inhibited.Conclusion：iDCs could induce the antigen-specific tolerance of T cells,which is related to the inhibition of Th1 production of IFNγ and IL-12.