Effects of sphingosine-1-phosphate receptor 1 phosphorylation in response to FTY720 during neuroinflammation
Hsing-Chuan Tsai, … , Christina W. Griffin, May H. Han
Hsing-Chuan Tsai, … , Christina W. Griffin, May H. Han
Published June 16, 2016
Citation Information: JCI Insight. 2016;1(9):e86462. https://doi.org/10.1172/jci.insight.86462.
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Research Article Immunology

Effects of sphingosine-1-phosphate receptor 1 phosphorylation in response to FTY720 during neuroinflammation

Abstract

Fingolimod (FTY720, Gilenya), a sphingosine-1-phosphate receptor (S1PR) modulator, is one of the first-line immunomodulatory therapies for treatment of relapsing-remitting multiple sclerosis (MS). Human S1PR1 variants have been reported to have functional heterogeneity in vitro, suggesting that S1PR1 function may influence FTY720 efficacy. In this study, we examined the influence of S1PR1 phosphorylation on response to FTY720 in neuroinflammation. We found that mice carrying a phosphorylation-defective S1pr1 gene [S1PR1(S5A) mice] were refractory to FTY720 treatment in MOG35-55-immunized and Th17-mediated experimental autoimmune encephalomyelitis (EAE) models. Long-term treatment with FTY720 induced significant lymphopenia and suppressed Th17 response in the peripheral immune system via downregulating STAT3 phosphorylation in both WT and S1PR1(S5A) mice. However, FTY720 did not effectively prevent neuroinflammation in the S1PR1(S5A) EAE mice as a result of encephalitogenic cells expressing C-C chemokine receptor 6 (CCR6). Combined treatment with FTY720 and anti-CCR6 delayed disease progression in S1PR1(S5A) EAE mice, suggesting that CCR6-mediated cell trafficking can overcome the effects of FTY720. This work may have translational relevance regarding FTY720 efficacy in MS patients and suggests that cell type–specific therapies may enhance therapeutic efficacy in MS.

Authors

Hsing-Chuan Tsai, Yingxiang Huang, Christopher S. Garris, Monica A. Moreno, Christina W. Griffin, May H. Han

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Figure 4

FTY720 treatment in vivo downregulated Th17 expression in the spleen of S1PR1(S5A) EAE mice.

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FTY720 treatment in vivo downregulated Th17 expression in the spleen of ...
MOG35-55-immunized C57BL/6J (WT) and S1PR1(S5A) EAE mice were treated with vehicle (1% cyclodextrin in PBS) or FTY720 (0.5 mg/kg) by daily i.p. injections up to day 8 after immunization. Splenocytes were harvested, and the total splenocyte counts were quantified by hemocytometer (A). Percentages of CD3+ (B), CD4+ (C), CD8+ (D), and CD11b+ (E) cells were quantified by flow cytometry. Splenocytes were also stimulated with PMA (50 ng/ml) and ionomycin (500 ng/ml) for 4 hours, and intracellular staining was performed to measure the expression of IL-17A, IFN-γ, and FOXP3 among CD4+ cells (F–I). Data represent 2 independent experiments (n = 4, mean ± SEM, *P < 0.05; **P < 0.01, ANOVA with Tukey’s multiple comparison test).