scholarly journals T-bet is essential for encephalitogenicity of both Th1 and Th17 cells

2009 ◽  
Vol 206 (7) ◽  
pp. 1549-1564 ◽  
Author(s):  
Yuhong Yang ◽  
Jeffrey Weiner ◽  
Yue Liu ◽  
Alan J. Smith ◽  
David J. Huss ◽  
...  

The extent to which myelin-specific Th1 and Th17 cells contribute to the pathogenesis of experimental autoimmune encephalomyelitis (EAE) is controversial. Combinations of interleukin (IL)-1β, IL-6, and IL-23 with transforming growth factor β were used to differentiate myelin-specific T cell receptor transgenic T cells into Th17 cells, none of which could induce EAE, whereas Th1 cells consistently transferred disease. However, IL-6 was found to promote the differentiation of encephalitogenic Th17 cells. Further analysis of myelin-specific T cells that were encephalitogenic in spontaneous EAE and actively induced EAE demonstrated that T-bet expression was critical for pathogenicity, regardless of cytokine expression by the encephalitogenic T cells. These data suggest that encephalitogenicity of myelin-specific T cells appears to be mediated by a pathway dependent on T-bet and not necessarily pathway-specific end products, such as interferon γ and IL-17.

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ani Grigorian ◽  
Michael Demetriou

Multiple sclerosis (MS) is an inflammatory demyelinating and neurodegenerative disease initiated by autoreactive T cells. Mgat5, a gene in the Asn (N-) linked protein glycosylation pathway, associates with MS severity and negatively regulates experimental autoimmune encephalomyelitis (EAE) and spontaneous inflammatory demyelination in mice. N-glycan branching by Mgat5 regulates interaction of surface glycoproteins with galectins, forming a molecular lattice that differentially controls the concentration of surface glycoproteins. T-cell receptor signaling, T-cell proliferation, TH1 differentiation, and CTLA-4 endocytosis are inhibited by Mgat5 branching. Non-T cells also contribute to MS pathogenesis and express abundant Mgat5 branched N-glycans. Here we explore whether Mgat5 deficiency in myelin-reactive T cells is sufficient to promote demyelinating disease. Adoptive transfer of myelin-reactive Mgat5−/− T cells into Mgat5+/+ versus Mgat5−/− recipients revealed more severe EAE in the latter, suggesting that Mgat5 branching deficiency in recipient naive T cells and/or non-T cells contribute to disease pathogenesis.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Xuebin Qu ◽  
Jingjing Han ◽  
Ying Zhang ◽  
Xingqi Wang ◽  
Hongbin Fan ◽  
...  

Abstract Background Toll-like receptor 4 (TLR4) is well known for activating the innate immune system; however, it is also highly expressed in adaptive immune cells, such as CD4+ T-helper 17 (Th17) cells, which play a key role in multiple sclerosis (MS) pathology. However, the function and governing mechanism of TLR4 in Th17 remain unclear. Methods The changes of TLR4 in CD4+ T cells from MS patients and experimental autoimmune encephalomyelitis (EAE) mice were tested. TLR4-deficient (TLR4−/−) naïve T cells were induced in vitro and transferred into Rag1−/− mice to measure Th17 differentiation and EAE pathology. DNA sequence analyses combining with deletion fragments and mutation analyses, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA) were used to explore the mechanism of TLR4 signaling pathway in regulating Th17 differentiation. Results The levels of TLR4 were increased in CD4+ Th17 cells both from MS patients and EAE mice, as well as during Th17 differentiation in vitro. TLR4−/− CD4+ naïve T cells inhibited their differentiation into Th17, and transfer of TLR4−/− CD4+ naïve T cells into Rag1−/− mice was defective in promoting EAE, characterized by less demyelination and Th17 infiltration in the spinal cord. TLR4 signal enhanced Th17 differentiation by activating RelA, downregulating the expression of miR-30a, a negative regulator of Th17 differentiation. Inhibition of RelA activity increased miR-30a level, but decreased Th17 differentiation rate. Furthermore, RelA directly regulated the expression of miR-30a via specific binding to a conserved element of miR-30a gene. Conclusions TLR4−/− CD4+ naïve T cells are inadequate in differentiating to Th17 cells both in vitro and in vivo. TLR4-RelA-miR-30a signal pathway regulates Th17 differentiation via direct binding of RelA to the regulatory element of miR-30a gene. Our results indicate modulating TLR4-RelA-miR-30a signal in Th17 may be a therapeutic target for Th17-mediated neurodegeneration in neuroinflammatory diseases.


2009 ◽  
Vol 206 (10) ◽  
pp. 2131-2139 ◽  
Author(s):  
Jens Nolting ◽  
Carolin Daniel ◽  
Sabine Reuter ◽  
Christina Stuelten ◽  
Peng Li ◽  
...  

It has been reported that retinoic acid (RA) enhances regulatory T (T reg) cell conversion by inhibiting the secretion of cytokines that interfere with conversion. This report shows that these conclusions provide a partial explanation at best. First, RA not only interfered with cytokine secretion but also with the ability of these cytokines to inhibit T reg cell conversion of naive T cells. Furthermore, RA enhanced conversion even in the absence of inhibitory cytokines. The latter effect depended on the RA receptor α (RARα) but did not require Smad3, despite the fact that RA enhanced Smad3 expression. The RARα1 isoform was not essential for RA-dependent enhancement of transforming growth factor β–driven conversion, suggesting that conversion can also be mediated by RARα2. Interleukin (IL)-6 strongly reduced RARα expression levels such that a deficiency of the predominant RARα1 isoform leaves too little RARα2 for RA to inhibit the generation of Th17 cells in the presence of IL-6.


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