Effects of 1,25-dihydroxyvitamin D3 on IL-17/IL-23 axis, IFN-γ and IL-4 expression in systemic lupus erythematosus induced mice model.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a multi-factorial autoimmune disease which may be characterized by T lymphocytes dysfunctions. Th17 cells have been identified as new effector cells, which play an important role in the pathogenesis. In recent years, immunomodulatory effect of vitamin D3 has been noticed. In the present experiment, the effect of vitamin D3 on the expression of IL-17, IL-23, IL-4 and IFN-γ were assessed in activated chromatin-induced mouse model for SLE.

MATERIALS AND METHODS: Five groups of mice were included in this study; Group one received active chromatin +CFA + PBS; Group 2 received vitamin D3 starting 2 weeks before disease induction; Group 3 received vitamin D3 (50 ng/day) starting with the disease establishment; Group 4 received non active chromatin +CFA + PBS; Group 5 received CFA + PBS. On day 56 splenocytes were isolated and gene expression of interleukin IL-17, IL-23, IL-4 and IFN-γ were analyzed by Real-Time PCR method. Proteinuria and serum anti-dsDNA and Th17 levels were measured using commercial kits.

RESULTS: The results showed that IL-17, IL-23, and IFN-γ mRNA expression, and IL-17 titers were decreased remarkably and that of IL-4 increased in mice which received vitamin D3 before SLE induction. Administration of vitamin D3 after the establishment of SLE failed to affect the IL-17 or IL-23 mRNA levels. Lastly, pre-treatment of mice with vitamin D3 decreased the anti-ds DNA antibody titer.

CONCLUSION: Our findings showed that vitamin D3 supplementation in lupus induced mice through modulating the expression rate of some inflammatory cytokines diminished the inflammatory conditions in SLE.