人脐血源性MSCs成骨诱导分化后对DCs的免疫抑制研究

目的探讨人脐血源性间充质干细胞(mesenchymal stem cells derived from umbilical cord blood,UCB-MSCs)经成骨诱导分化后,对树突状细胞(dendritic cells,DCs)的分化、成熟及免疫功能的影响。方法对UCB-MSCs通过细胞形态、表面标记及成骨诱导分化能力进行鉴定;在外周血单核细胞培养体系中加入GM-CSF+IL-4+TNF-α,刺激DCs诱导分化及成熟;收集与成骨诱导分化前后UCB-MSCs共培养的DCs,流式细胞仪检测DCs免疫表型的表达情况;将成熟DCs作为刺激因素,外周血淋巴细胞作为反应细胞,3H-TdR标记β液体闪烁计数仪检测与成骨诱导分化前后UCB-MSCs共培养后,DCs刺激淋巴细胞增殖能力的变化。结果人UCB-MSCs成骨诱导分化后能抑制DCs表面CD40、CD80、CD83、CD86和MHC-II的表达,上调CD14的表达;DCs具有明显刺激淋巴细胞增殖的功能,而UCB-MSCs成骨诱导分化后能显著抑制DCs刺激的淋巴细胞增殖。结论成骨诱导分化的UCB-MSCs在体外可抑制同种异体DCs的分化、成熟及免疫功能,为UCB-MSCs作为同种异体源性种子细胞在骨组织工程中的应用提供了依据。

Immune suppression on dendritic cells by mesenchymal stem cells derived from human umbilical blood after osteogenesis induction

Human umbilical cord blood-derived mesenchymal stem cells(UCB-MSCs) have low immunogenicity and immunomodulatory effects.In order to study the effects of osteogenesis differentiated UCB-MSCs after on dendritic cells(DC) differentiation,maturation,and immune function,UCB-MSCs after osteogenesis induction were added to DCs from in vitro cytokines-stimulated peripheral blood monocytes.DCs were then examined for the expression of markers characteristic and their ability to stimulate allogeneic lymphocytes by -thymidine incorporation using a liquid scintillation counter.The result showed that UCB-MSCs after osteogenic differentiation could inhibit the expression of the DCs surface CD40,CD80,CD83,CD86 and MHC-II,but raised CD14 expression.Furthmore,UCB-MSCs after osteogenic differentiation significantly inhibited the ability of DC to stimulate the proliferation of lymphocytes.Therefore,UCB-MSCs after osteogenic differentiation in vitro can inhibit allogeneic DCs differentiation,maturation and immune function,providing a basis for allogeneic UCB-MSCs as seed cells in bone tissue engineering.