间质干细胞对SLE患者外周血T细胞的免疫抑制作用

目的 探讨体外骨髓间质干细胞(MSC)对SLE患者外周血T淋巴细胞(T细胞)的免疫调节作用及可能机制.方法 分离培养健康人骨髓MSC并鉴定其纯度,分离SLE患者外周血T细胞,在植物血凝素(PHA)刺激下,用不同比例的MSC与T细胞作用.分为T细胞、T细胞+MSC_1(T:MSC_1=1:0.02)、T细胞+MSC_2(T:MSC_2=1:0.2)3组.采用MTF法检测T细胞增殖,流式细胞仪检测T细胞CD152~+和CD28~+的表达,实时PCR测定IFN-γ和IL-6 mRNA的表达水平.结果 MSC可明显抑制SLE患者T细胞增殖.T细胞增殖在T细胞组A值为0.765±0.036,T细胞+MSC_1组为0.484±0.032,T细胞+MSC_2组为0.308±0.025,与对照组相比,A值均明显降低(P＜0.05),T细胞+MSC_1组和T细胞+MSC_2组之间差异也有统计学意义(P＜0.05).T细胞组CD28~+细胞百分比为(74.73±3.74)%,T细胞+MSC_1组为(60.39±3.92)%,T细胞+MSC_2组为(45.05±3.46)%,与对照组相比均明显降低(P＜0.05),T细胞+MSC_1组和T细胞+MSC_2组之间差异也有统计学意义(P＜0.05).MSC对T细胞CD152+表达无显著影响.MSC明显抑制T细胞IFN-γ、IL-6 mRNA表达(P＜0.05),并且随着MSC数昔的增加,抑制作用增强.结论 MSC对SLE患者T细胞有免疫抑制作用,可能与抑制T细胞增殖、抑制T细胞CD28~+表达和抑制T细胞IFN-γ、IL-6 mRNA表达有关.

Immunosuppressive effects of mesenchymal stem cells on peripheral blood T lymphocytes from patients with systemic lupus erythematosus

Objective To investigate the immunoregulatory effects of mesenchymal stem cells (MSCs)on peripheral blood T lymphocytes from patients with systemic lupus erythematosus(SLE)in vitro and their potential mechanism.Methods MSCs were isolated from the bone marrow of 3 healthy human volunteers,cultivated and identified.Under phytohemagglutinin(PHA)stimulating,peripheral blood T lymphocytes from 8 patients with SLE were treated with MSCs with the T lymphocyte/MSC ratio being 50:1 in group B and 5:1 in group C or without MSCs(group A).MTT assay was used to detect the proliferation of T lymphocytes.flow cytometry to analyze the expressions of surface markers CD152 and CD28 on T lymphocytes.and real time PCR to measure the mRNA expressions of interleukin-6 and interferon-γ,in the T lymphocytes.Results MSCs could markedly inhibit the proliferation of T lymphocytcs.The proliferation of T lymphocytes expressed as absorbance value at 570 nm was 0.484±0.032 in group B.0.308±0.025 in group C,significantly lower than that in group A(0.765±0.036,both P＜0.05),and significant difference was also observed between group C and B(P＜0.05).In the case of the percentage of CD28 positive T lymphocytes.group B and C were significantly lower than group A(60.39%±3.92%and 45.05%±3.46%vs 74.73%±3.74%,both P＜0.05),and group B significantly differed from group C(P＜0.05).MSCs had no obvious effect on the expression of CD152 on T lymphocytes,but significantly suppressed the mRNA expression of interleukin-6 and interferon-γ(both P＜0.05).and the suppressive effect was enhanced with the incrgase in MSC count.ConclusionsMSCs exert an immunosuppressive effect on T lymphocytes from patients with SLE,likely through inhibiting the proliferation,CD28 expression,interleukin-6 and interferon-γ mRNA expression of T lymphocytes.