Vitamin D Modulates the Expression of IL-27 and IL-33 in the Central Nervous System in Experimental Autoimmune Encephalomyelitis (EAE).

Abstract

It has been reported that vitamin D has broad anti-inflammatory and immunomodulatory effects. To evaluate the effects of vitamin D on the expression of IL-27 and IL-33 in a model of experimental autoimmune encephalomyelitis (EAE). EAE was induced in C57BL/6 mice by immunization with myelin oligodendroglial glycoprotein mixed with complete Freund's adjuvant. The mice were administered with PBS or olive oil, intraperitoneally, in the control groups and vitamin D (200 ng every two days) in the treatment group, from day +3 to +30. At day 31, the mice were scarified and their spinal cords and brains were harvested. The expression of the IL-27 and IL-33 mRNA in the spinal cord was measured using real time-PCR. In PBS- or olive oil-treated EAE mice the expression of IL-27 P28 mRNA was significantly lower than that in the healthy control group (p<0.002). In both PBS- and olive oil-treated EAE groups, the expression of IL-27 EBI3 mRNA was also lower than that observed in the healthy group, but the differences were not significant. In vitamin D-treated EAE group, the expression of IL-27 P28 and IL-27 EBI3 were significantly higher compared with the olive oil-treated EAE groups (p<0.002 and p<0.04, respectively). The expression of IL-33 was significantly higher in PBS-or olive oil-treated EAE groups compared with healthy mice (p<0.05 and p<0.02, respectively). Vitamin D significantly decreased the expression of IL-33 compared with PBS- or olive oil-treated EAE mice (p<0.04, p<0.02, respectively). The PBS- or olive oil -treated EAE mice showed the clinical symptoms of EAE at days 9 and 10, respectively. The vitamin D-treated EAE group exhibited the symptoms at day 12 post immunization. The maximum mean clinical score and mean pathological scores were also significantly lower in vitamin D-treated EAE group, in comparison with PBS- or olive oil treated EAE mice (p<0.001). Vitamin D may modulate the expression of IL-27 and IL-33 in the spinal cord of EAE mice and also ameliorate the clinical symptoms of the disease.