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背景:由同种异基因骨髓间充质干细胞诱导的成骨细胞移植免疫反应各家报道不一致,差别明显。目的:体外观察由骨髓间充质干细胞诱导而成的成骨细胞对T细胞的免疫调节作用及特点。方法:用Ficoll-Hypaque梯度密度离心法分离出兔骨髓单个核细胞,体外扩增,获取第3代细胞,经典化学方法诱导为成骨细胞,将其按照不同的比例加入到T细胞形成双向混合淋巴细胞培养体系中,在第3,5,7天,用MTT比色法检测各组混合淋巴细胞培养体系中的T细胞增殖情况,24h后用流式细胞仪分析各组T细胞亚群凋亡情况。结果与结论:诱导后成骨细胞混合淋巴细胞培养体系中,成骨细胞对T细胞的增殖有抑制作用,在一定范围内,抑制作用具有量效关系。诱导后成骨细胞剂量大,时间延长,抑制程度增强;3次平均抑制率相比:1:20组低于1:80组(P<0.01);1:40组低于1:80组(P<0.05);诱导后成骨细胞能引起T细胞亚群凋亡,其中CD4+(凋亡率8.57%)亚群不如CD8+(凋亡率15.31%)细胞亚群凋亡显著(P<0.01)。结果显示诱导的成骨细胞在体外能够通过细胞凋亡途径抑制T细胞的增殖,特别是CD8+。但这种抑制不是特别强,表明诱导的成骨细胞虽有一定的免疫性,但其免疫性较低。
BACKGROUND: Osteoblast allograft immune responses induced by allogeneic bone marrow mesenchymal stem cells have been reported inconsistently. OBJECTIVE: To observe the immunoregulatory effect and characteristics of osteoblasts induced by bone marrow mesenchymal stem cells on T cells in vitro. METHODS: Rabbit bone marrow mononuclear cells were isolated by Ficoll-Hypaque gradient density centrifugation and expanded in vitro to obtain the third generation of cells. The osteoblasts were induced by classical chemical methods and added into T cells according to different ratios to form a bi-directional mixture Lymphocyte culture system, on the 3rd, 5th, 7th day, MTT colorimetry was used to detect the proliferation of T cells in the mixed lymphocyte culture system of each group. After 24 hours, the T cell subsets in each group were analyzed by flow cytometry Death situation. RESULTS AND CONCLUSION: Osteoblasts inhibited the proliferation of T cells in induced osteoblasts mixed lymphocyte culture system. In a certain range, the inhibitory effect was dose-response relationship. Compared with 1: 20 group (P <0.01), the average inhibition rate of 3 times in 1: 20 group was lower than that in 1: 40 group (P <0.01) P <0.05). After induction, osteoblasts could induce apoptosis of T lymphocyte subsets. The percentage of CD4 + (8.57%) subpopulation was less than that of CD8 + cells (15.31%) (P <0.01) . The results show that in vitro induced osteoblasts can inhibit the proliferation of T cells through the apoptotic pathway, especially CD8 +. However, this inhibition is not particularly strong, indicating that although induced osteoblasts have some immunity, but their immunity is low.