1 Department of Plastic Surgery, The First Affiliated Hospital, China Medical University , Shenyang, Liaoning, China .
2 Department of Pharmaceutical Science, The First Affiliated Hospital, China Medical University , Shenyang, Liaoning, China .
Stem Cells Dev. 2018 Sep 1;27(17):1191-1202. doi: 10.1089/scd.2018.0033.
Adipose-derived stem cells (ADSCs) are a type of multipotent mesenchymal stem cells with immunosuppressive capacities. However, the underlying mechanisms involved in the inhibitory effects of ADSCs on T cells are not completely elucidated. In this study, human peripheral blood mononuclear cells (PBMCs) stimulated with anti-CD3/CD28 antibody-coated beads were cultured with or without allogeneic ADSCs (ADSC-to-PBMC ratio, 1:5). Surface marker levels, violet-labeled cell proliferation, apoptosis, interferon-gamma (IFN-gamma) production, and nuclear factor-kappaB (NF-kappaB) phosphorylation of CD4 and CD8 T cells were detected using flow cytometry. It was observed that ADSCs significantly suppressed the proliferation and IFN-gamma production but enhanced apoptosis of both CD4 and CD8 T cells in T cell receptor (TCR)-stimulated PBMCs. The expressions of programmed death-ligand 1 (PD-L1) and galectin 9 (Gal-9) on ADSCs were significantly upregulated and induced during coculture with PBMCs. TCR-stimulated CD4 and CD8 T cells cultured with ADSCs had higher expression levels of programmed death-1 (PD-1) and T cell immunoglobulin and mucin-containing protein-3 (TIM-3) than those in cells cultured without ADSCs. Moreover, the suppressive effects of ADSCs on T cells in terms of proliferation and IFN-gamma production were significantly reversed in the presence of anti-PD-L1 and anti-Gal-9 antibodies. Importantly, the phosphorylation of NF-kappaB in CD4 and CD8 T cells cocultured with ADSCs was significantly inhibited, and this inhibition was significantly attenuated via the PD-L1 and Gal-9 blockades. In conclusion, human ADSCs perform immunoregulatory functions partially through the inhibition of NF-kappaB activation in T cells via the PD-L1/PD-1 and Gal-9/TIM-3 pathways, which provide new insights into the mechanism of human ADSC-mediated immunomodulation.
脂肪来源的干细胞（ADSCs）是一种具有免疫抑制能力的多能间充质干细胞。然而，ADSCs 对 T 细胞抑制作用的潜在机制尚未完全阐明。在这项研究中，用抗-CD3/CD28 抗体包被珠刺激的人外周血单个核细胞（PBMC）与或不与同种异体 ADSC（ADSC 与 PBMC 的比例为 1:5）共培养。通过流式细胞术检测 CD4 和 CD8 T 细胞的表面标志物水平、紫色标记的细胞增殖、凋亡、干扰素-γ（IFN-γ）产生和核因子-κB（NF-κB）磷酸化。结果发现，ADSCs 显著抑制 TCR 刺激的 PBMC 中 CD4 和 CD8 T 细胞的增殖和 IFN-γ产生，但促进其凋亡。在与 PBMC 共培养期间，ADSCs 上程序性死亡配体 1（PD-L1）和半乳糖凝集素 9（Gal-9）的表达明显上调并被诱导。与无 ADSC 培养的细胞相比，用 ADSC 培养的 TCR 刺激的 CD4 和 CD8 T 细胞表达更高水平的程序性死亡受体 1（PD-1）和 T 细胞免疫球蛋白和粘蛋白-3（TIM-3）。此外，在存在抗 PD-L1 和抗 Gal-9 抗体的情况下，ADSCs 对 T 细胞增殖和 IFN-γ产生的抑制作用明显逆转。重要的是，与 ADSC 共培养的 CD4 和 CD8 T 细胞中 NF-κB 的磷酸化明显受到抑制，通过 PD-L1 和 Gal-9 阻断，这种抑制作用明显减弱。综上所述，人 ADSC 通过 PD-L1/PD-1 和 Gal-9/TIM-3 通路抑制 T 细胞中 NF-κB 的激活来发挥免疫调节功能，这为理解人 ADSC 介导的免疫调节机制提供了新的见解。
