未成熟DCs诱导同种免疫低应答及 CD14分子在DCs上的表达

目的：从健康人外周血单核细胞诱导树突状细胞（DCs），并且证实未成熟DCs在体外可以诱 导同种T细胞的低应答。 方法：人外周血单核细胞经GM-CSF，IL-4及TNF-α联合诱导，分化出不同发育阶段的DCs。采用再次混合淋巴细胞培养的方法观察未成熟DCs处理过的T细胞对与未成熟DCs同一来源的T细胞的应答能力。 结果：在DCs的未成熟期与成熟期均中度以上表达CD14分子；随着培养时间的不同DCs内吞能 力不断变化，在第7天达高峰，且内吞量高于相同培养时间的单核细胞（P＜001）；在再次混合淋巴细胞反应中，供者未成熟DCs预处理的受者T细胞当再次被供者的T细胞刺激时应答降低，而对第三者的T细胞刺激则表现强反应性。 结论：诱导人外周血单核细胞获得不同发育阶段的DCs，经过再次混合淋巴细胞反应发现具 有中度表达共刺激分子的未成熟DCs在体外可以诱导T细胞免疫低应答。

Expression of CD14+ on dendritic cells in vitro and allo-hypo-immuno-responsiveness induced by immature dendritic cells

Objective To induce immature dendritic cells(imDCs) and mature dendritic cells from human peripheral blood monocyte, and to testify the induction of allo-hypo-immuno-responsiveness by imDCs in vitro. Methods Monocytes were cultured with the medium including GM-CSF, IL-4 or TNF-α. In immaturation of DCs, the secondary mixed lymphocyte reaction(MLR) assay was used in vitro to analyze response of T cells activated by allogenic imDCs to T cells from the same one as DCs and the other one. Results DCs in the immaturation and maturation phases expressed CD14 molecules. The endocytosis ability of these DCs peaked at the seventh day in culture, and the endocytosis ability of the DCs was better than that of the monocytes in culture for the same time (P<0.01). In the secondary MLR, pretreated by imDCs, T cells showed low responsiveness to T cells from the same one as imDCs, while a strong proliferation to the other one′s T cells could be detected. Conclusion imDCs with the middling level of costimulate molecules could induce an specific allo-hypo-immuno-responsiveness in vitro.