Center for Stem Cell Research and Regenerative Medicine, Tulane University School of Medicine, New Orleans, LA, USA.
Department of Cell and Molecular Biology, Tulane University School of Science and Engineering, New Orleans, LA, USA.
J Neuroinflammation. 2018 Mar 13;15(1):77. doi: 10.1186/s12974-018-1099-3.
The therapeutic efficacy of adipose-derived stem cells (ASCs) has been investigated for numerous clinical indications, including autoimmune and neurodegenerative diseases. Less is known using the crude adipose product called stromal vascular fraction (SVF) as therapy, although our previous studies demonstrated greater efficacy at late-stage disease compared to ASCs in the experimental autoimmune encephalomyelitis (EAE) mouse, a model of multiple sclerosis. In this study, SVF cells and ASCs were administered during the pathogenic progression, designated as early disease, to elucidate immunomodulatory mechanisms when high immune cell activities associated with autoimmune signaling occur. These implications are essential for clinical translation when considering timing of administration for cell therapies.
We investigated the effects of SVF cells and ASCs by analyzing the spleens, peripheral blood, and central nervous system tissues throughout the course of EAE disease following administration of SVF cells, ASCs, or vehicle. In vitro, immunomodulatory potentials of SVF cells and ASCs were measured when exposed to EAE-derived splenocytes.
Interestingly, treatment with SVF cells and ASCs transiently enhanced the severity of disease directly after administration, substantiating this critical immunomodulatory signaling. More importantly, it was only the EAE mice treated with SVF cells that were able to overcome the advancing pathogenesis and showed improvements by the end of the study. The frequency of lesions in spinal cords following SVF treatment correlated with diminished activities of the T helper type 1 cells, known effector cells of this disease. Co-cultures with splenocytes isolated from EAE mice revealed transcripts of interleukin-10 and transforming growth factor-β, known promoters of regulatory T cells, that were greatly expressed in SVF cells compared to ASCs, and expression levels of signaling mediators related to effector T cells were insignificant in both SVF cells and ASCs.
This is the first evidence, to date, to elucidate a mechanism of action of SVF treatment in an inflammatory, autoimmune disease. Our data supports key immunomodulatory signaling between cell therapies and T cells in this T cell-mediated disease. Together, treatment with SVF mediated immunomodulatory effects that diminished effector cell activities, promoted regulatory T cells, and reduced neuroinflammation.
脂肪来源的干细胞(ASCs)的治疗效果已经在许多临床适应症中进行了研究,包括自身免疫和神经退行性疾病。虽然我们之前的研究表明,在实验性自身免疫性脑脊髓炎(EAE)小鼠模型(多发性硬化症的模型)中,晚期疾病的疗效优于 ASC,但作为治疗方法的称为基质血管部分(SVF)的粗脂肪产物的研究较少。在这项研究中,在疾病进展期间(称为早期疾病)给予 SVF 细胞和 ASC,以阐明与自身免疫信号相关的高免疫细胞活性发生时的免疫调节机制。当考虑细胞治疗的给药时机时,这些意义对于临床转化至关重要。
我们通过分析 EAE 疾病期间 SVF 细胞、ASC 或载体给药后整个脾脏、外周血和中枢神经系统组织,来研究 SVF 细胞和 ASC 的作用。在体外,当 SVF 细胞和 ASC 暴露于源自 EAE 的脾细胞时,测量了它们的免疫调节潜力。
有趣的是,SVF 细胞和 ASC 的治疗直接在给药后暂时加重了疾病的严重程度,证实了这种关键的免疫调节信号。更重要的是,只有接受 SVF 细胞治疗的 EAE 小鼠才能够克服进展中的发病机制,并在研究结束时显示出改善。SVF 治疗后脊髓中的病变频率与已知是这种疾病的效应细胞的 Th1 细胞的活性降低相关。与源自 EAE 小鼠的脾细胞共培养揭示了白细胞介素 10 和转化生长因子-β的转录物,已知是调节性 T 细胞的促进剂,与 ASC 相比,SVF 细胞中大量表达,而与效应 T 细胞相关的信号转导介质的表达水平在 SVF 细胞和 ASC 中均无意义。
这是迄今为止阐明 SVF 治疗在炎症性自身免疫性疾病中的作用机制的第一个证据。我们的数据支持细胞治疗与 T 细胞之间在这种 T 细胞介导的疾病中的关键免疫调节信号。总之,SVF 的治疗介导了免疫调节作用,减弱了效应细胞的活性,促进了调节性 T 细胞,并减少了神经炎症。