ABSTRACT
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.