Vitamin D down-regulates the expression of some Th17 cell-related cytokines, key inflammatory chemokines, and chemokine receptors in experimental autoimmune encephalomyelitis

Objectives: A spectrum of immunomodulatory properties was attributed to vitamin D (VD). Here, the VD effects on expression of some Th17 cell- related cytokines, chemokines and chemokine receptors were investigated in experimental autoimmune encephalomyelitis (EAE). Methods: One group of C57BL/6 mice, considered as healthy group, was treated with phosphate buffered saline (PBS). EAE was induced in other three groups and treated from day +3 to +30 with PBS, olive oil (VD vehicle) or 200 ng of VD. At day 31, the expression of interleukin-17 (IL-17), IL-23, chemokine (C-C motif) ligand 20 (CCL20), CCL22, CC chemokine receptor 4 (CCR4) and CCR6 in spinal cord and serum IL-17 and IL-23 levels were measured by real-time PCR and ELISA, respectively. Results: The expression of IL-17, IL-23 P19, IL-23 P40, CCL20, CCL22 and CCR4 in spinal cord and serum IL-17 and IL-23 levels in PBS-administrated EAE mice were significantly increased compared with healthy group. In EAE mice treated with VD, the expression of aforementioned parameters was significantly reduced in comparison with PBS-administrated EAE mice. Conclusion: VD down-regulates the expression of some inflammatory cytokines, chemokines and chemokine receptors in EAE mice. The possible therapeutic potential of VD in multiple sclerosis can be considered in future investigation.