Increase in CD4+Foxp3+ Regulatory T cells and Amelioration of Experimental Autoimmune Encephalomyelitis in Mice Treated with IL-27

Background and purpose: In multiple sclerosis (MS) and its murine model, experimental autoimmune encephalomyelitis (EAE), chronic inflammation damages the myelin of central nervous system. Recently, interleukin-27 (IL-27) has been recognized as a feasible choice for treatment of autoimmune diseases such as MS due to its anti-inflammatory properties. However, the underlying mechanisms have not yet been specified clearly. The present study, investigated the immunomdulatory effects of IL-27 in C57BL/6 mice with EAE. Materials and methods: In this experimental study, two groups of EAE mice (test and control groups) received intraperitoneal injection of P240-mIL-27 (200 µg) and P240 plasmid (200 µg), respectively. The disease severity was evaluated daily for 30 days. At the end of the treatment period, the mice were sacrificed and the levels of IL-17, IFN-γ, IL-6, and IL-10 were measured in splenocytes culture media using ELISA method. Also, the percentage of CD4+Foxp3+ regulatory T cells (Treg) in spleen cells was analyzed using flow cytometry. Results: Severity of EAE significantly decreased in test group (P240-mIL27), compared to that of the control group. In test group, the levels of IL-17, IFN-γ, and IL-6 were significantly lower (P<0.001), while IL-10 levels were significantly higher compared to those of the control group (P<0.001). Moreover, the percentage of Treg cells in test group was significantly higher than that of the control mice (P<0.001). Conclusion: IL-27 can be a suitable choice in treatment of inflammatory diseases such as MS via increasing Treg cells and IL-10, and suppression of inflammatory cytokines.