Pachler Karin, Ketterl Nina, Desgeorges Alexandre, Dunai Zsuzsanna A, Laner-Plamberger Sandra, Streif Doris, Strunk Dirk, Rohde Eva, Gimona Mario
GMP Unit, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University (PMU), Strubergasse 22, 5020 Salzburg, Austria.
Research Program Nanovesicular Therapies, Paracelsus Medical University (PMU), Strubergasse 22, 5020 Salzburg, Austria.
Int J Mol Sci. 2017 Jul 1;18(7):1413. doi: 10.3390/ijms18071413.
The regenerative and immunomodulatory activity of mesenchymal stromal cells (MSCs) is partially mediated by secreted vesicular factors. Extracellular vesicles (EVs) exocytosed by MSCs are gaining increased attention as prospective non-cellular therapeutics for a variety of diseases. However, the lack of suitable in vitro assays to monitor the therapeutic potential of EVs currently restricts their application in clinical studies. We have evaluated a dual in vitro immunomodulation potency assay that reproducibly reports the inhibitory effect of MSCs on induced T-cell proliferation and the alloantigen-driven mixed leukocyte reaction of pooled peripheral blood mononuclear cells in a dose-dependent manner. Phytohemagglutinin-stimulated T-cell proliferation was inhibited by MSC-derived EVs in a dose-dependent manner comparable to MSCs. In contrast, inhibition of alloantigen-driven mixed leukocyte reaction was only observed for MSCs, but not for EVs. Our results support the application of a cell-based in vitro potency assay for reproducibly determining the immunomodulatory potential of EVs. Validation of this assay can help establish reliable release criteria for EVs for future clinical studies.
间充质基质细胞（MSCs）的再生和免疫调节活性部分由分泌的囊泡因子介导。MSCs胞吐的细胞外囊泡（EVs）作为多种疾病的潜在非细胞疗法越来越受到关注。然而，目前缺乏合适的体外试验来监测EVs的治疗潜力，这限制了它们在临床研究中的应用。我们评估了一种双重体外免疫调节效能试验，该试验可重复性地报告MSCs对诱导的T细胞增殖的抑制作用以及对汇集的外周血单个核细胞的同种异体抗原驱动的混合淋巴细胞反应的抑制作用，且呈剂量依赖性。与MSCs类似，MSCs来源的EVs以剂量依赖性方式抑制植物血凝素刺激的T细胞增殖。相比之下，仅在MSCs中观察到对同种异体抗原驱动的混合淋巴细胞反应的抑制，而在EVs中未观察到。我们的结果支持应用基于细胞的体外效能试验来可重复性地确定EVs的免疫调节潜力。该试验的验证有助于为未来的临床研究建立可靠的EVs放行标准。
