Critical role of metabotropic glutamate receptor 4 in bone marrow-derived dendritic cells in the Th17 cell differentiation and the melanogenesis of B16 cells

Vitiligo is an acquired pigmentary disorder resulting from selective destruction of melanocytes. Emerging studies have suggested that T helper cell 17 (Th17) is potentially implicated in vitiligo development and progression. It was recently discovered that metabotropic glutamate receptor 4 (mGluR4) can modulate Th17-mediated adaptive immunity. However, the influence of mGluR4 on melanogenesis of melanocytes has yet to be elucidated. In the present study, we primarily cultured mouse bone marrow-derived dendritic cells (BMDC) and then knocked down and over-expressed mGluR4 using transfection. Transduced BMDC were co-cultured with CD4+ T cells and the expression of Th17-related cytokines were measured. The morphology and melanogenesis of B16 cells were observed after being treated with co-culture medium of CD4+ T cells and transduced BMDC. We found that mGluR4 knockdown did not affect the co-stimulatory CD80 and CD86 upregulation after lipopolysaccharide stimulation but did increase the expression of Th17-related cytokines, and further down-regulated the expression of microphthalmia-associated transcription factor (MITF) and the downstream genes, decreased melanin production, and destroyed the morphology of B16 cells. Conversely, over-expression of mGluR4 reduced the expression of CD80 and CD86, suppressed the production of Th17-related cytokines, increased the expression of MITF, and did not destroy the morphology of B16 cells. Our study confirmed that mGluR4 modulated the Th17 cell polarization and resulted in the alteration of melanogenesis and morphology of B16 cells. Collectively, these findings suggest mGluR4 might be a potent target involved in the immune pathogenesis of vitiligo.

Therapeutic Effect of SPK1 Gene Transfected Adipose Derived Mesenchymal Stem Cells on Experimental Autoimmune Encephalomyelitis Mice and Its Effect on T Helper Cell 17/Regulatory T Cells Balance / 中国医学科学院学报

Objective To investigate the therapeutic effect of SPK1 gene transfected adipose derived mesenchymal stem cells(ADMSC)on experimental autoimmune encephalomyelitis mice and the effect on T helper cell 17(Th17)/regulatory T(Treg) cells balance. Methods EAE was induced by myelin oligodendrocyte glycoprotein 35-55 in mice.Totally 44 mice were randomly divided into four groups:normal control group(NC group),model group(EAE group),ADMSC group,and ADMSC-SPK1 group.Forty days after injection,the pathological changes of brain and spinal cord,Th17/Treg-related inflammatory markers in brain tissue,expressions of interleukin-17A(IL-17A)and forkhead box protein p3(Foxp3)in brain and spinal cord tissue,and flow cytometric results of spleen immune cells were detected. Results Forty days after the injection,serious inflammatory cell infiltration and demyelination occurred in the brain and spinal cord of EAE group,whereas demyelination and axonal injury were improved in ADMSC group and ADMSC-SPK1 group.Compared with EAE group,the ADMSC group and ADMSC-SPK1 group had significantly improved levels of IL-17A(

Effect of Hydroxychloroquine Treatment on Dry Eyes in Subjects with Primary Sjögren's Syndrome: a Double-Blind Randomized Control Study

The effect of hydroxychloroquine (HCQ) on dry eye has not been fully determined. This study aimed to compare the 12-week efficacy of HCQ medication with that of a placebo in the management of dry eye in primary Sjögren's syndrome (pSS). A double-blind, randomized control study was conducted in 39 pSS subjects from May 2011 through August 2013. pSS was diagnosed based on the classification criteria of the American-European Consensus Group. Subjects received 300 mg of HCQ or placebo once daily for 12 weeks and were evaluated at baseline, 6, and 12 weeks, with a re-visit at 16 weeks after drug discontinuance. The fluorescein staining score, Schirmer test score, tear film break-up time (TBUT), and ocular surface disease index (OSDI) were measured, and tears and blood were collected for ESR, IL-6, IL-17, B-cell activating factor (BAFF), and Th17 cell analysis. Color testing was performed and the fundus was examined to monitor HCQ complications. Twenty-six subjects completed the follow-up. The fluorescein staining score and Schirmer test score did not differ significantly. The OSDI improved with medication in the HCQ group but was not significantly different between the groups. TBUT, serum IL-6, ESR, serum and tear BAFF, and the proportion of Th17 cells did not change in either group. HCQ at 300 mg daily for 12 weeks has no apparent clinical benefit for dry eye and systemic inflammation in pSS (ClinicalTrials.gov. NCT01601028).

Elevated Levels of T Helper 17 Cells Are Associated with Disease Activity in Patients with Rheumatoid Arthritis

BACKGROUND: Interleukin-17 (IL-17)-producing T helper (Th) 17 cells are considered as a new subset of cells critical to the development of rheumatoid arthritis (RA). We aimed to investigate the distribution of Th1 and Th17 cells and their association with disease activity, and determine the Th17-related cytokine levels in the peripheral blood of RA patients. METHODS: Peripheral blood mononuclear cells from 55 RA and 20 osteoarthritis (OA) patients were stimulated with mitogen, and the distributions of CD4+Interferon (INF)+IL-17- (Th1 cells) and CD4+INF-IL-17+ (Th17 cells) were examined by flow cytometry. Serum levels of IL-6, IL-17, IL-21, IL-23, and tumor necrosis factor (TNF)-alpha were measured by ELISA. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded. The 28-joint disease activity score (DAS28) was also assessed. RESULTS: The median percentage of Th17 cells was higher in RA patients than in OA patients (P=0.04), and in active than in inactive RA (P=0.03), whereas that of Th1 cells was similar in both groups. Similarly, the levels of IL-17, IL-21, and IL-23 were detected in a significantly higher proportion of RA patients than OA patients and the frequencies of detectable IL-6, IL-17, and IL-21 were higher in active RA than in inactive RA group. The percentage of Th17 cells positively correlated with the DAS28, ESR, and CRP levels. CONCLUSIONS: These observations suggest that Th17 cells and Th17-related cytokines play an important role in RA pathogenesis and that the level of Th17 cells in peripheral blood is associated with disease activity in RA.