Fig. 1

Schematic diagram of MSC-mediated reconstruction of the normal Th17/Treg balance. From the bottom-up: A Soluble factors: sTNFR1, CCL2, IL-17RA and IL-37; B Receptor-ligand axis: PD-L1/PD-1, ICOSL-ICOS, FAS-FASL; C Extracellular vesicles: miRNAs, proteins, tolerance molecules, etc.; D Mitochondrial translocation: inhibiting the glycolytic process in CD4⁺ T cells and Th17 cells, and enhancing the oxidative phosphorylation process that induces Treg generation; E Metabolic reprogramming: by enhancing the glycolytic metabolism of MSCs as well as inhibiting the glycolytic metabolic process of CD4⁺ T cells; and F Autophagy: The autophagic process of MSCs mediates the differentiation of MSCs to CD4⁺ T cells and their subpopulations. Through the above pathways, MSCs inhibit Th17 cell production and their pro-inflammatory effects, induce Treg proliferation and immunosuppressive functions, and thus regulate the Th17/Treg balance