Figure 7.

Graphic overview of key experimental procedures. LPS, Poly (I:C), TNFα, and IFNγ were used at different concentrations, individually or in combination, to prime in vitro cultured MenSCs. The optimal priming strategy was identified by ELISA in terms of IDO1 release. For the ELISA results, the MenSCs were primed with 100 ng/mL IFNγ and TNFα, and the phenotypic profiles of MenSCs* and MenSCs were determined by flow cytometry. Moreover, the MenSCs and MenSCs* were cultured with ITS (insulin-transferrin-selenium)-DMEM medium serum-free. After 96 h, conditioned media were concentrated to obtain the total secretome fraction, which was also enriched in extracellular vesicles. Finally, these secretomes were characterized by next-generation sequencing (NGS), nano-flow cytometry in combination with size exclusion chromatography (nFC+ SEC), as well as with lymphocyte activation assays. Images have been created with BioRender [55].