Human multipotent mesenchymal stromal cells cytokine priming promotes RAB27B-regulated secretion of small extracellular vesicles with immunomodulatory cargo

• Published in: Stem cell research & therapy 2020-12, Vol.11 (1), p.539-539, Article 539
• Main Authors: Cheng, Anastasia, Choi, Dongsic, Lora, Maximilien, Shum-Tim, Dominique, Rak, Janusz, Colmegna, Inés
• Format: Article
• Language: English
• Subjects: Age; Aging; Analysis; Biological response modifiers; CD4 antigen; Cell proliferation; Cell signaling; Child; Clinical trials; Cytokines; Cytokines - metabolism; Deoxyribonucleic acid; DNA; Ethylenediaminetetraacetic acid; Exosomes; Extracellular vesicles; Extracellular Vesicles - metabolism; Flow cytometry; Growth factors; Homeopathy; Humans; Hypoxia; Immunological tolerance; Immunomodulation; Inflammation; Interferon gamma; Lymphocytes; Lymphocytes T; Materia medica and therapeutics; Mesenchymal stem cells; Mesenchymal Stem Cells - metabolism; Mesenchyme; MicroRNA; miRNA; Mitochondrial DNA; mRNA; MSC; Multipotent mesenchymal stromal cells; Nanoparticles; Paracrine signalling; Pediatrics; Proteomics; rab GTP-Binding Proteins - genetics; RAB27B; Secretome; sEVs; siRNA; Stem cells; Stromal cells; T cells; Therapeutic applications; Therapeutics; Tumor necrosis factor-α; Type 2 diabetes; γ-Interferon
• ISSN: 1757-6512; 1757-6512
• DOI: 10.1186/s13287-020-02050-6

The paracrine effects of multipotent mesenchymal stromal cells (MSCs) are mediated by their secretome composed by soluble factors (i.e., cytokines, growth factors, hormones) and extracellular vesicles (EVs). EVs promote intercellular communication, and the EV cargoes [e.g., proteins, soluble factors, microRNAs (miRNAs), messenger RNA (mRNA), DNA] reflect the molecular and functional characteristics of their parental cells. MSC-derived EVs (MSC-EVs) are currently evaluated as subcellular therapeutics. A key function of the MSC secretome is its ability to promote immune tolerance (i.e., immunopotency), a property that is enhanced by priming approaches (e.g., cytokines, hypoxia, chemicals) and inversely correlates with the age of the MSC donors. We evaluated mechanisms underlying MSC vesiculation and the effects of inflammation and aging on this process. We evaluated the effects of interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) on human adipose-derived MSC: (a) vesiculation (custom RT Profiler PCR Array), (b) EV profiles (Nanoparticle Tracking Analysis and Nanoparticle Flow Cytometry), (c) EV cargo (proteomic analysis and Western blot analysis), and (d) immunopotency (standard MSC:CD4 T cell proliferation inhibition assay). We confirmed the role of RAB27B on MSC vesiculation (RAB27B siRNA) and assessed its differential contribution to vesiculation in adult and pediatric MSCs (qPCR). Cytokine priming upregulated RAB27B in adipose-derived MSCs increasing their secretion of exosome-like small EVs (sEVs;