Objective: To explore the effect of human bone marrow mesenchymal stem cells (MSCs) with ectopic high OCT4 expression on T-cell proliferation, activation and secretion in vitro.
Methods: Peripheral blood mononuclear cells were isolated from healthy children. Anti-CD3 and anti-CD28 monoclonal antibodies were used to activate T lymphocytes, which were stimulated by interleukin (IL)-2 for one week in vitro. Then MSCs with ectopic high OCT4 expression (MSC-OCT4) were co-cultured with activated T lymphocytes. After one week of co-culture, the supernatant was collected and the levels of Th1/Th2 cytokines [IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ] were determined by flow cytometry. The lymphocytes after one week of co-culture were collected and counted by Countstar software. After the proportions of activated/inactivated T cell subsets were determined by flow cytometry, the absolute lymphocyte counts were calculated and expressed as mean ± standard deviation.
Results: Compared with control T cell alone culture group, the proliferation of CD3+ T cells, CD3+CD4+ T cells, and CD3+CD8+ T cells were significantly inhibited in MSC group and MSC-OCT4 group. Compared with MSC, MSC-OCT4 could inhibit CD3+CD8+ T cell proliferation better (P =0.049), and mainly inhibited early T cell activation. Compared with control T cell alone culture group, the levels of IL-2 and INF-γ were significantly down-regulated both in MSC group and MSC-OCT4 group.After co-culture with T cells for one week, the level of IL-6 significantly increased in MSC group and MSC-OCT4 group compared with that before co-culture. Compared with control MSC group, MSC-OCT4 group had higher viable cell numbers after 1 week of co-culture (P =0.019), and could resist the inhibition of proliferation by higher concentration of mitomycin C.
Conclusion: Both MSC and MSC-OCT4 can inhibit the proliferation and activation of IL-2-stimulated T cells in vitro. After overexpression of OCT4, MSC has better proliferation ability in vitro and can inhibit the proliferation of CD3+CD8+ T cells more effectively, which may have a better and more lasting immunosuppressive ability to regulate the balance of Th1/Th2.
题目: 异位高表达OCT4的人骨髓间充质干细胞对T淋巴细胞功能的影响.
目的: 探讨异位高表达OCT4的人骨髓间充质干细胞（MSC）在体外对T细胞增殖、活化及分泌功能的影响。.
方法: 分离健康儿童外周血单个核细胞，使用Anti-CD3/CD28单克隆抗体体外激活T淋巴细胞，白介素（IL）2体外刺激培养的T细胞1周。建立异位高表达OCT4的MSC（MSC-OCT4）与活化T细胞的体外共培养体系，收集共培养1周后的上清液，流式细胞仪测定Th1/Th2细胞因子（IL-2、IL-4、IL-6、IL-10、肿瘤坏死因子-α、γ干扰素）水平。收集共培养1周后的淋巴细胞，通过Countstar软件进行计数，用流式细胞仪测定T细胞及活化T细胞亚群的比例后，计算出绝对值，以均数±标准差表示。.
结果: 与对照单独T细胞培养组相比，MSC及MSC-OCT4均能显著抑制CD3+ T细胞、CD3+CD4+ T细胞和CD3+CD8+ T细胞增殖。与MSC相比，MSC-OCT4能更好地抑制CD3+CD8+ T细胞增殖（P =0.049），且主要抑制早期T细胞活化。与对照单独T细胞培养组相比，MSC及MSC-OCT4均能显著下调细胞因子IL-2和γ干扰素水平。与T细胞共培养1周后，MSC与MSC-OCT4组细胞因子IL-6水平显著增加。与对照MSC组相比，MSC-OCT4组在共培养1周后活细胞数更高（P =0.019），且能耐受更高浓度丝裂霉素C的抑制增殖作用。.
结论: MSC及MSC-OCT4在体外均能抑制IL-2刺激的T细胞增殖及活化，过表达OCT4后MSC能更强地抑制CD3+CD8+ T细胞增殖，且具有更好的体外增殖能力，可能具有更好更持久地调节Th1/Th2造血因子平衡的作用。.
Keywords: OCT4; cytokine; human bone marrow mesenchymal stem cells; immuno-regulation; transcription factor.