骨髓间充质干细胞对体外分化的原态(naive)T细胞分泌细胞因子的影响

目的观察骨髓间充质干细胞(MSC)对原态(naive)T细胞的反应,探讨其免疫调节机制。方法传代培养3代的MSC经60Co照射后与脐血CD34+细胞分化产生的原态T细胞共孵育1周,用ELISA方法检测培养上清细胞因子的变化。结果孵育7d后,与MSC共孵育后T细胞数量明显增加,为(9.15±0.68)×105/孔,而原态T细胞单独培养组为(4.87±1.33)×105/孔(P<0.05);ELISA检测共孵育组IFNγ分泌减少为(1.147±0.181)pg/ml,而原态T细胞单独培养组为(4.897±0.189)pg/ml、共孵育组IL2分泌增加为(16.141±2.729)pg/ml,而原态T细胞单独培养组为(2.551±0.460)pg/ml,未检测到IL4和IL10。结论MSC有一定的抗原性,与MSC共孵育导致原态T淋巴细胞增殖,MSC可能通过直接或间接抑制T细胞产生IFN-γ发挥免疫抑制作用。为进一步阐明MSC免疫调节机制提出新的线索。

The effect of MSC on cytokine production by naive T cell differentiated in vitro

OBJECTIVE: To investigate the effect of mesenchymal stem cell (MSC) on naive T cell and to explore its mechanism of immunoregulation. METHODS: After culturing for 3 passages, MSC was incubated with naive T cells differentiated from cord blood CD34(+) cells in vitro. Variance of cytokine produced by naive T cell in culture supernatant was analyzed by enzyme-linked immunoassays. RESULTS: On the 7th day of co-culture, a mild proliferation of T cells in the co-culture group was observed: (9.15 +/- 0.68) x 10(5)/well in MSCs + naive T cells group versus (4.87 +/- 1.33) x 10(5)/well in naive T cells alone group (P < 0.05). IFN-gamma production was lower in MSCs + naive T cells group than that in naive T cells alone group: (1.147 +/- 0.181) pg/ml versus (4.897 +/- 0.189) pg/ml (P < 0.05), but IL-2 production was higher in the co-culture group: (16.141 +/- 2.729) pg/ml versus (2.551 +/- 0.460) pg/ml (P < 0.05). Neither IL-4 nor IL-10 were detected. CONCLUSIONS: MSC have allogeneic effect on naive T cell, but may suppress alloreactive T lymphocyte and reduce the incidence of GVHD partly by decreased IFN-gamma production. The result may provide new clues for explaining immunoregulatory mechanism of MSC.