从Th1、Th17细胞极化探讨iMDC负载P258-73肽段干预EAN的机制

Effect of iMDC pulsed with P258-73 peptide on the Th17/Th1 cells polarization in EAN

目的观察未成熟髓源树突状细胞负载P258-73肽段干预实验性自身免疫性神经炎的效果,及干预对IL-17、IFN-γmRNA表达的影响,从Th1、Th17细胞极化的角度探讨其干预机制。方法P258-73aa负载于体外培养的iMDC,获得P258-73aa-iMDC,用P253-78aa和CFA免疫Lewis大鼠制成EAN动物模型,免疫前7d各组大鼠分别给予PBS、iMDC及P258-73aa-iMDC干预。观察发病情况并作临床评分及病理改变。收集引流淋巴结细胞检测淋巴细胞增殖反应,RT-PCR技术检测大鼠脾脏、淋巴结和坐骨神经中IL-17、IFN-γmRNA的表达。结果P258-73aa-iMDC干预组大鼠的平均临床评分、抗原特异性淋巴细胞增殖反应和坐骨神经炎性细胞浸润均降低;IFN-γ及IL-17mRNA在脾脏、淋巴结和坐骨神经中的表达也明显降低。结论P258-73aa-iMDC通过影响IL-17、IFN-γ的分泌,影响Th1、Th17细胞极化,抑制抗原特异性淋巴细胞增殖,从而减轻EAN的发病,这可能是其诱导免疫耐受的机制之一。

Objective To explore the improving potential of immature myeloid dendritic cell （ iMDC ） pulsed with P258-73aa peptide （P258-73aa-iMDC） in experimental autoimmune neuritis （EAN） ,and to explore the role of Th1/Th17 cells polarization in this tolerance therapy by detecting the expression of IL-17 and IFN-γ mRNA. Methods P258-73aa21 was pulsed with iMDC in vitro to get P258-73aa-iMDC. Rats of each group were immunized with P253-78aa and CFA. 7 days before immunization, each group was injected with PBS or iMDC or P258-73aa-iMDC respectively. Clinical scores of each group and histopathological changes were evaluated and the lymphocyte proliferation response was assayed;IL-17 and IFN-γ, mRNA in spleen,lymph node and sciatic nerves were measured by RT-PCR. Results The P258-73aa-iMDC interferred group had lower average clinical score and suppressed antigen specific lymphocyte proliferation, as well as milder infiltration by the inflammatory cells in sciatic nerves. Meanwhile, the expression of IL-17/IFN-γ mRNA in spleen, lymph node and sciatic nerves were also decreased. Conclusion The protective effect of P258-73aa-iMDC could be associated with the inhibition of lymphocyte proliferation and IL-17 ,IFN-γ through the polarization of Th1/Th17 cells,which is probably one of the tolerance mechanism of P258-73aa-iMDC in EAN.