title: Nanosized UCMSC-derived extracellular vesicles but not conditioned medium exclusively inhibit the inflammatory response of stimulated T cells: implications for nanomedicine.
abstract: Undesired immune responses have drastically hampered outcomes after allogeneic organ transplantation and cell therapy, and also lead to inflammatory diseases and autoimmunity. Umbilical cord mesenchymal stem cells (UCMSCs) have powerful regenerative and immunomodulatory potential, and their secreted extracellular vesicles (EVs) are envisaged as a promising natural source of nanoparticles to increase outcomes in organ transplantation and control inflammatory diseases. However, poor EV preparations containing highly-abundant soluble proteins may mask genuine vesicular-associated functions and provide misleading data. Here, we used Size-Exclusion Chromatography (SEC) to successfully isolate EVs from UCMSCs-conditioned medium. These vesicles were defined as positive for CD9, CD63, CD73 and CD90, and their size and morphology characterized by NTA and cryo-EM. Their immunomodulatory potential was determined in polyclonal T cell proliferation assays, analysis of cytokine profiles and in the skewing of monocyte polarization. In sharp contrast to the non-EV containing fractions, to the complete conditioned medium and to ultracentrifuged pellet, SEC-purified EVs from UCMSCs inhibited T cell proliferation, resembling the effect of parental UCMSCs. Moreover, while SEC-EVs did not induce cytokine response, the non-EV fractions, conditioned medium and ultracentrifuged pellet promoted the secretion of pro-inflammatory cytokines by polyclonally stimulated T cells and supported Th17 polarization. In contrast, EVs did not induce monocyte polarization, but the non-EV fraction induced CD163 and CD206 expression and TNF-α production in monocytes. These findings increase the growing evidence confirming that EVs are an active component of MSC's paracrine immunosuppressive function and affirm their potential for therapeutics in nanomedicine. In addition, our results highlight the importance of well-purified and defined preparations of MSC-derived EVs to achieve the immunosuppressive effect.
authors.affiliation: REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Monguió-Tortajada
authors.affiliation: ICREC Research Program, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain; Center of Regenerative Medicine in Barcelona, Barcelona, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Roura
authors.affiliation: ICREC Research Program, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Gálvez-Montón
authors.affiliation: Cell Processing Laboratory, Parc Científic i Tecnològic Universitat de Girona, Girona, Spain.
authors.forename: Josep Maria
authors.initials: JM
authors.lastname: Pujal
authors.affiliation: Innate Immunity Group, Health Sciences Research Institute Germans Trias i Pujol, Badalona, Spain.
authors.forename: Gemma
authors.initials: G
authors.lastname: Aran
authors.affiliation: Innate Immunity Group, Health Sciences Research Institute Germans Trias i Pujol, Badalona, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Sanjurjo
authors.affiliation: REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, Badalona, Spain.
authors.forename: Marcel la
authors.initials: M
authors.lastname: Franquesa
authors.affiliation: Innate Immunity Group, Health Sciences Research Institute Germans Trias i Pujol, Badalona, Spain.
authors.forename: Maria-Rosa
authors.initials: MR
authors.lastname: Sarrias
authors.affiliation: ICREC Research Program, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain; Cardiology Service, Germans Trias i Pujol University Hospital, Badalona, Spain; Department of Medicine, UAB, Barcelona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Bayes-Genis
authors.affiliation: REMAR-IVECAT Group, Health Science Research Institute Germans Trias i Pujol, Can Ruti Campus, Badalona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, Badalona, Spain.
authors.forename: Francesc E
authors.initials: FE
authors.lastname: Borràs
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects; D020285:Cryoelectron Microscopy; D017077:Culture Media, Conditioned / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D000067128:Extracellular Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007155:Immunologic Factors / Q000378:metabolism*; D007249:Inflammation / Q000473:pathology*; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D050997:Nanomedicine / Q000379:methods; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology*; D014470:Umbilical Cord / Q000166:cytology*
chemical_list: D017077:Culture Media, Conditioned; D016207:Cytokines; D007155:Immunologic Factors
keywords: exosomes; immunomodulation; inflammation; nanosized extracellular vesicles; size exclusion chromatography.; umbilical cord mesenchymal stem cell