Background: Multiple sclerosis (MS) is a neurodegenerative disease that characterized by damage to the myelin sheath. Schwann cells are main glial cells in the peripheral nervous and have important role in myelinated axons. The purpose of this study is to evaluate the therapeutic efficacy of Schwann cell-derived exosomes on experimental autoimmune encephalomyelitis (EAE).

Methods: In this study, female C57BL/6 mice were divided into two groups with similar age and weight. EAE was induced in the female C57BL/6 mice by using myelin oligodendrocyte glycopeptide (MOG) 35-55. Exosomes were isolated from Schwann cells culture by repeated centrifugation and filtration steps. A group of EAE mice were subjected to three injections of exosomes weekly. Animals were evaluated daily for clinical score and profile cytokines were measured after three weeks appearance of clinical symptoms.

Results: The results of the study showed that the mean of the maximum severity of the disease in the treated group was significantly (p value<0.05) less than the control group. Schwann cell-derived exosomes increased the levels of anti-inflammatory cytokine interleukin (IL)-10 as compared to the control group, but no significant differences were observed in the level of interferon (IFN) -γ.

Conclusion: The present study showed that Schwann cell-derived exosomes modulated EAE via TH2 induction immune response and may be considered as a new strategy for treatment of multiple sclerosis.