Therapeutic effects of extracellular vesicles derived from mesenchymal stem cells primed with disease-conditioned-immune cells in systemic lupus erythematosus.

Background: Systemic lupus erythematosus (SLE) is an incurable chronic autoimmune disease of unknown etiology. Therefore, the development of new treatments is urgently needed. This study aimed to investigate the therapeutic effects of extracellular vesicles (EV) derived from immortalized mesenchymal stem cells (iMSCs) primed with conditioned media obtained from disease-conditioned immune cells (CM-EV) and iMSC-derived EV (ASC-EV) in a murine model of SLE.

Methods: Female NZB/W F1 mice were divided into the control (C, n = 15), ASC-EV (E, n = 15), and CM-EV (CM, n = 15) groups. Mice in the C, E, and CM groups were intravenously administered saline, ASC-EV, and CM-EV, respectively, once weekly from 6 to 42 weeks of age.

Results: Compared to the ASC-EV, the CM-EV showed a significant increase in TGF-β1 production and miR-155-5p and miR-142-3p expression. CM-EV treatment increased survival, decreased anti-dsDNA antibody levels, and ameliorated renal histopathology. Although ASC-EV treatment significantly reduced the incidence of severe proteinuria and improved renal histopathology, it did not significantly improve survival rate. ASC-EV or CM-EV treatment significantly decreased the proportion of pro-inflammatory macrophages (CD11c + CD206-; M1) and M1:M2 ratio. Additionally, CM-EV treatment significantly increased the expression of anti-inflammatory macrophages (CD11c-CD206 + ; M2). Moreover, CM-EV treatment significantly decreased the expression of lupus-specific miRNAs (miR-182-5p and miR-183-5p) in the spleen.

Conclusions: EV derived from iMSCs primed with conditioned media obtained from disease-conditioned immune cells exert immunomodulatory effects and ameliorate SLE in a murine model.