骨髓间充质干细胞对异体外周血B淋巴细胞的免疫调节作用

目的 探讨骨髓间充质干细胞(mesenchymal stem cells, MSC)在体外对异体外周血B淋巴细胞的免疫调节作用.方法 用密度梯度离心法从骨髓中分离、培养MSC,从外周血中分离单个核细胞,L-亮氨酸甲酯去除单核细胞,以2-氨乙基硫脲溴化物(AET)处理绵羊红细胞(SRBC)的花环形成法,去除T淋巴细胞获得纯化的B淋巴细胞.用羊抗人IgM单克隆抗体(anti-IgM)刺激与或未与MSC或其培养上清共培养3d的B淋巴细胞,应用MTT法测8淋巴细胞的增殖,ELISA法测培养上清中免疫球蛋白IgG、lgM的产生,应用流式细胞术分别检测与MSC共培养24、48h后B淋巴细胞的凋亡.结果 MSC及其培养上清抑制由anti-IgM诱导的B淋巴细胞的增殖和分泌IgG、IgM,且随着MSC细胞数量及其培养上清浓度的增加,这种抑制越明显.流式细胞术结果显示,与MSC共培养不同时间的B淋巴细胞的凋亡变化无统计学意义,MSC抑制B淋巴细胞的增殖存在暂时性和可逆性.结论 MSC对异体外周血8淋巴细胞存在免疫调节作用,并且这种调控机制是复杂的,不仅与MSC细胞数量有关,还与细胞间的相互作用和MSC分泌的细胞因子有关.

The immunoregulatory effects of bone marrow mesenchymal stem cells on allogeneic peripheral B lymphocyte

Objective To study the immunoregulatory effects of bone marrow mesenchymal stem cells (MSC) on allogeneic peripheral B lymphocytes in vitro. Methods MSCs were isolated and cultured from bone marrow by gradient centrifugation. Mononuclear cells were isolated routinely from peripheral blood, then monocytes were eliminated by L-leucine methy ester method. Remained T lymphocytes were eliminated by AET-SRBC rosette method. The action of MSCs and its supernatant on B lymphocytes proliferation in the presence of anti-human IgM goat antibodies (anti-IgM) was investigated by MTT. The IgG, IgM in the supernatant were detected by ELISA. The percent of apoptosis B lymphocytes, co-cultured with MSCs for 24 or 48h, was assayed by FACS. Results MSCs and its supernatant inhibited B lymphocytes proliferation and Ig secretion. The inhibitory effect depended on the amount of MSCs and condition of its supernatant. The date of FACS indicated that the apoptosis ratio of B lymphocytes, co-cultured with MSCs for different times, were non-significant. The inhibitory effect of MSCs on B lymphocytes was temporary and reversible. Conclusion MSCs have immunoregulatory effects on B lymphocytes, and its mechanisms are complex, not only correlating with the concentration of MSCs but also the action between cells and the secretory cytokine of MSCs.