Independent human mesenchymal stromal cell-derived extracellular vesicle preparations differentially attenuate symptoms in an advanced murine Graft-versus-Host-Disease model

ABSTRACT: Extracellular vesicles (EVs) harvested from conditioned media of human mesenchymal stromal cells (MSCs) suppress acute inflammation in various disease models and promote regeneration of damaged tissues. Following successful treatment of an acute steroid-refractory Graft-versus-Host disease (GvHD) patient with EVs prepared from conditioned media of human bone marrow-derived MSCs, we focus on improving the MSC-EV production for the clinical application. Independent MSC-EV preparations all produced according to a standardized procedure, reveal broad immunomodulatory differences. Only a proportion of our MSC-EV products effectively modulate immune responses in a multi-donor mixed lymphocyte reaction (mdMLR) assay. To explore the relevance of such differences, we have established an optimized mouse GvHD model. The functional testing of selected MSC-EV preparations demonstrate that MSC-EV preparations revealing immunomodulatory capabilities in the mdMLR assay also effectively suppress GvHD symptoms in this model. In contrast, MSC-EV preparations, lacking such in vitro activities, also fail to modulate GvHD symptoms in vivo. Searching for differences of the active and inactive MSC-EV preparations, we failed to identify concrete proteins or miRNAs that could serve as surrogate markers. Thus, standardized MSC-EV production strategies may not be sufficient to warrant manufacturing of MSC-EV products with reproducible qualities. Consequently, given this functional heterogeneity, every individual MSC-EV preparation considered for the clinical application should be evaluated for its therapeutic potency prior to administration to patients. Here, we qualified the mdMLR assay for such analyses.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Stem Cell

SUBMITTER: Frank Stein  

LAB HEAD: Prof. Dr. Bernd Giebel

PROVIDER: PXD032744 | Pride | 2023-06-12

REPOSITORIES: Pride