Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by production of inflammatory cytokines and autoreactive antibodies due to the loss of immune tolerance. Recognition of self-nucleic acids by intracellular Toll-like receptors (TLRs) can overactivate immune responses and this abnormal activation of TLRs contributes to the pathogenesis of the disease. In recent years, anti-inflammatory and immunomodulatory effects of 1,25-dihydroxyvitamin D3 (VitD3) on the immune system has received particular attention. The present study investigated the effects of vitamin D3 on the expression of TLR3, TLR7, and TLR9 in SLE patients. Study participants included 20 SLE patients and 20 age- and sex-matched healthy controls. Peripheral blood mononuclear cells (PBMCs) were isolated and cultured in the presence or absence of vitamin D3 (50 nM). Then RNA was extracted, cDNA was synthesized and gene expression levels of TLR3, TLR7, and TLR9 were assessed using real-time PCR. Up-regulated expression levels of TLR7 and TLR9 were observed in the PBMCs of SLE patients in comparison with controls. Culturing PBMCs with vitamin D3 significantly down-regulated the expression of TLR3 (8.86 ± 4.2 for SLE patients vs. 45.34 ± 18.6 for control; P = 0.03), TLR7 (17.91 ± 7.7 for SLE patients vs. 242.37 ± 89.6 for controls; P = 0.0001) and TLR9 (4.67 ± 1.9 for SLE patients vs. 8.9 ± 1.5 for controls; P = 0.007) in SLE patients in comparison with healthy controls. The results of the current study suggest that vitamin D3 could exert some of its immunomodulatory effects in SLE patients via affecting the expression levels of some TLRs. J. Cell. Biochem. 118: 4831-4835, 2017. © 2017 Wiley Periodicals, Inc.
Keywords: PERIPHERAL BLOOD MONONUCLEAR CELLS; REAL-TIME PCR; SYSTEMIC LUPUS ERYTHEMATOSUS; TOLL LIKE RECEPTORS; VITAMIN D3.
© 2017 Wiley Periodicals, Inc.