2′-5′ oligoadenylate synthetase-like 1 (OASL1) deficiency suppresses central nervous system damage in a murine MOG-induced multiple sclerosis model

Type I Interferon (IFN-I) is critical for antiviral and antitumor defense. Additionally, IFN-I has been used for treating multiple sclerosis (MS), a chronic autoimmune disease of the central nervous system (CNS). Recently, we reported that 2′-5′ oligoadenylate synthetase-like 1 (OASL1) negatively regulates IFN-I production upon viral infection and tumor challenge. Therefore, OASL1 deficient (Oasl1−/−) mice are resistant to viral infections and tumor challenge. In this study, we examined whether OASL1 plays a negative role in the development of autoimmune MS by using Oasl1−/− mice and a murine MS model, myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE). Oasl1−/− mice showed enhanced resistance to EAE development compared to wild-type (WT) mice. Additionally, EAE-induced Oasl1−/− mice showed fewer infiltrated immune cells such as T cells and macrophages in the CNS and less CNS inflammation, compared to WT mice. Collectively, these results indicate that OASL1 deficiency suppresses the development of MS-like autoimmunity and suggest that negative regulators of IFN-I could be good therapeutic targets for treating MS in humans.