Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0014070 (encephalomyelitis)
 13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interleukin (IL)-17 is a proinflammatory cytokine primarily secreted by Th17 cells, which are a CD4(+) T-cell subset. Th17 cells and IL-17 are important in the pathogenesis of multiple sclerosis and in its established animal model, experimental autoimmune encephalomyelitis (EAE). However, it is unclear whether IL-17 contributes to EAE immune tolerance. We used the myelin basic protein (MBP) peptide MBP 68-86 to induce nasal tolerance to EAE, and simultaneously interfered with the tolerance by treatment with different doses of IL-17. We found that IL-17 dramatically interfered with MBP 68-86-induced immune tolerance. IL-17 administration increased IL-6 release, skewing T cell differentiation towards Th17 cells and decreasing the number of Treg cells. This led to an imbalance between Treg cells and Th17 cells and spurred the development of EAE.
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PMID:IL-17 eliminates the therapeutic effects of myelin basic protein-induced nasal tolerance in experimental autoimmune encephalomyelitis by activating IL-6. 1905 97

Galectin-3 (Gal-3) is a member of the beta-galactoside-binding lectin family and plays an important role in inflammation. However, the precise role of Gal-3 in autoimmune diseases remains obscure. We have investigated the functional role of Gal-3 in experimental autoimmune encephalomyelitis (EAE) following immunization with myelin oligodendrocyte glycoprotein (MOG)35-55 peptide. Gal-3 deficient (Gal-3-/-) mice developed significantly milder EAE and markedly reduced leukocyte infiltration in the CNS compared with similarly treated wild-type (WT) mice. Gal-3-/- mice also contained fewer monocytes and macrophages but more apoptotic cells in the CNS than did WT mice. Following Ag stimulation in vitro, lymph node cells from the immunized Gal-3-/- mice produced less IL-17 and IFN-gamma than did those of the WT mice. In contrast, Gal-3-/- mice produced more serum IL-10, IL-5, and IL-13 and contained higher frequency of Foxp3+ regulatory T cells in the CNS than did the WT mice. Furthermore, bone marrow-derived dendritic cells from Gal-3-/- mice produced more IL-10 in response to LPS or bacterial lipoprotein than did WT marrow-derived dendritic cells. Moreover, Gal-3-/- dendritic cells induced Ag-specific T cells to produce more IL-10, IL-5, and IL-12, but less IL-17, than did WT dendritic cells. Taken together, our data demonstrate that Gal-3 plays an important disease-exacerbating role in EAE through its multifunctional roles in preventing cell apoptosis and increasing IL-17 and IFN-gamma synthesis, but decreasing IL-10 production.
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PMID:Galectin-3 deficiency reduces the severity of experimental autoimmune encephalomyelitis. 1912 60

Dendritic cells (DCs) appear in higher numbers within the CNS as a consequence of inflammation associated with autoimmune disorders, such as multiple sclerosis, but the contribution of these cells to the outcome of disease is not yet clear. Here, we show that stimulatory or tolerogenic functional states of intracerebral DCs regulate the systemic activation of neuroantigen-specific T cells, the recruitment of these cells into the CNS and the onset and progression of experimental autoimmune encephalomyelitis (EAE). Intracerebral microinjection of stimulatory DCs exacerbated the onset and clinical course of EAE, accompanied with an early T-cell infiltration and a decreased proportion of regulatory FoxP3-expressing cells in the brain. In contrast, the intracerebral microinjection of DCs modified by tumor necrosis factor alpha induced their tolerogenic functional state and delayed or prevented EAE onset. This triggered the generation of interleukin 10 (IL-10)-producing neuroantigen-specific lymphocytes in the periphery and restricted IL-17 production in the CNS. Our findings suggest that DCs are a rate-limiting factor for neuroinflammation.
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PMID:Intracerebral dendritic cells critically modulate encephalitogenic versus regulatory immune responses in the CNS. 1912 92

IL-17 is the signature cytokine of recently discovered Th type 17 (Th17) cells, which are prominent in defense against extracellular bacteria and fungi as well as in autoimmune diseases, such as rheumatoid arthritis and experimental autoimmune encephalomyelitis in animal models. IL-25 is a member of the IL-17 family of cytokines, but has been associated with Th2 responses instead and may negatively cross-regulate Th17/IL-17 responses. IL-25 can initiate an allergic asthma-like inflammation in the airways, which includes recruitment of eosinophils, mucus hypersecretion, Th2 cytokine production, and airways hyperreactivity. We demonstrate that these effects of IL-25 are entirely dependent on the adaptor protein CIKS (also known as Act1). Surprisingly, this adaptor is necessary to transmit IL-17 signals as well, despite the very distinct biologic responses that these two cytokines elicit. We identify CD11c(+) macrophage-like lung cells as physiologic relevant targets of IL-25 in vivo.
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PMID:The adaptor protein CIKS/Act1 is essential for IL-25-mediated allergic airway inflammation. 1915 11

Transforming growth factor beta (TGF-beta) plays a role both in the induction of Treg and in the differentiation of the IL-17-secreting T cells (Th17) which drive inflammation in experimental autoimmune encephalomyelitis (EAE). We investigated the role that thrombospondin-1 (TSP-1) dependent activation of TGF-beta played in the generation of an encephalitic Th17 response in EAE. Upon immunization with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)), TSP-1 deficient (TSP-1(null)) mice and MOG(35-55) TCR transgenic mice that lack of TSP-1 (2D2 x TSP-1(null)) exhibited an attenuated form of EAE, and secreted lower levels of IL-17. Adoptive transfer of in vitro-activated 2D2 x TSP-1(null) T cells induced a milder form of EAE, independent of TSP-1 expression in the recipient mice. Furthermore, in vitro studies demonstrated that anti-CD3/anti-CD28 pre-activated CD4+ T cells transiently upregulated latent TGF-beta in a TSP-1 dependent way, and such activation of latent TGF-beta was required for the differentiation of Th17 cells. These results demonstrate that TSP-1 participates in the differentiation of Th17 cells through its ability to activate latent TGF-beta, and enhances the inflammatory response in EAE.
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PMID:Deficiency of thrombospondin-1 reduces Th17 differentiation and attenuates experimental autoimmune encephalomyelitis. 1918 83

Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a widely expressed neuropeptide originally discovered in the hypothalamus. It closely resembles vasoactive intestinal peptide (VIP), a neuropeptide well known to inhibit macrophage activity, promote Th2-type responses, and enhance regulatory T cell (Treg) production. Recent studies have shown that administration of PACAP, like VIP, can attenuate dramatically the clinical and pathological features of murine models of autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE) and collagen-induced arthritis. However, specific roles (if any) of endogenous VIP and PACAP in the protection against autoimmune diseases have not been explored. Here, we subjected PACAP-deficient mice to myelin oligodendrocyte glycoprotein (MOG(35-55))-induced EAE. MOG immunization of PACAP-deficient mice triggered heightened clinical and pathological manifestations of EAE compared to wild-type mice. The increased sensitivity was accompanied by enhanced mRNA expression of proinflammatory cytokines (TNFalpha, IL-6, IFN-gamma, IL-12p35, IL-23p19, and IL-17), chemokines (MCP-1/CCL2, MIP-1alpha/CCL3, and RANTES/CCL5), and chemotactic factor receptors (CCR1, CCR2, and CCR5), but downregulation of the anti-inflammatory cytokines (IL-4, IL-10, and TGF-beta) in the spinal cord. Moreover, the abundance of CD4(+)CD25(+)FoxP3(+) Tregs in lymph nodes and levels of FoxP3 mRNA in the spinal cord were also diminished. The reduction in Tregs was associated with increased proliferation and decreased TGF-beta secretion in lymph node cultures stimulated with MOG. These results demonstrate that endogenous PACAP provides protection in EAE and identify PACAP as an intrinsic regulator of Treg abundance after inflammation.
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PMID:Pituitary adenylyl cyclase-activating polypeptide is an intrinsic regulator of Treg abundance and protects against experimental autoimmune encephalomyelitis. 1919 Jan 79

Cell-based therapies are attractive approaches to promote myelin repair. Recent studies demonstrated a reduction in disease burden in mice with experimental allergic encephalomyelitis (EAE) treated with mouse mesenchymal stem cells (MSCs). Here, we demonstrated human bone marrow-derived MSCs (BM-hMSCs) promote functional recovery in both chronic and relapsing-remitting models of mouse EAE, traced their migration into the injured CNS and assayed their ability to modulate disease progression and the host immune response. Injected BM-hMSCs accumulated in the CNS, reduced the extent of damage and increased oligodendrocyte lineage cells in lesion areas. The increase in oligodendrocytes in lesions may reflect BM-hMSC-induced changes in neural fate determination, since neurospheres from treated animals gave rise to more oligodendrocytes and less astrocytes than nontreated neurospheres. Host immune responses were also influenced by BM-hMSCs. Inflammatory T-cells including interferon gamma producing Th1 cells and IL-17 producing Th17 inflammatory cells and their associated cytokines were reduced along with concomitant increases in IL-4 producing Th2 cells and anti-inflammatory cytokines. Together, these data suggest that the BM-hMSCs represent a viable option for therapeutic approaches.
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PMID:Human bone marrow-derived mesenchymal stem cells induce Th2-polarized immune response and promote endogenous repair in animal models of multiple sclerosis. 1919 36

The cellular prion protein (PrP(C)) is widely expressed in neural and non-neural tissues, but its function is unknown. Elucidation of the part played by PrP(C) in adaptive immunity has been a particular conundrum: increased expression of cell surface PrP(C) has been documented during T-cell activation, yet the functional significance of this activation remains unclear, with conflicting data on the effects of Prnp gene knockout on various parameters of T-cell immunity. We show here that Prnp mRNA is highly inducible within 8-24 h of T-cell activation, with surface protein levels rising from 24 h. When measured in parallel with CD69 and CD25, PrP(C) is a late activation antigen. Consistent with its up-regulation being a late activation event, PrP deletion did not alter T-cell-antigen presenting cell conjugate formation. Most important, activated PrP(0/0) T cells demonstrated much reduced induction of several T helper (Th) 1, Th2, and Th17 cytokines, whereas others, such as TNF-alpha and IL-9, were unaffected. These changes were investigated in the context of an autoimmune model and a bacterial challenge model. In experimental autoimmune encephalomyelitis, PrP-knockout mice showed enhanced disease in the face of reduced IL-17 responses. In a streptococcal sepsis model, this constrained cytokine program was associated with poorer local control of infection, although with reduced bacteremia. The findings indicate that PrP(C) is a potentially important molecule influencing T-cell activation and effector function.
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PMID:A role of cellular prion protein in programming T-cell cytokine responses in disease. 1920 74

Persistent viral infection and its associated chronic diseases are a global health concern. Interleukin (IL) 17-producing Th17 cells have been implicated in the pathogenesis of various autoimmune diseases, and in protection from bacterial or fungal infection. However, the role of Th17 cells in persistent viral infection remains unknown. We report that Th17 cells preferentially develop in vitro and in vivo in an IL-6-dependent manner after Theiler's murine encephalomyelitis virus infection. Th17 cells promote persistent viral infection and induce the pathogenesis of chronic demyelinating disease. IL-17 up-regulates antiapoptotic molecules and, consequently, increases persistent infection by enhancing the survival of virus-infected cells and blocking target cell destruction by cytotoxic T cells. Neutralization of IL-17 augments virus clearance by eliminating virus-infected cells and boosting lytic function by cytotoxic T cells, leading to the prevention of disease development. Thus, these results indicate a novel pathogenic role of Th17 cells via IL-17 in persistent viral infection and its associated chronic inflammatory diseases.
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PMID:Th17 cells enhance viral persistence and inhibit T cell cytotoxicity in a model of chronic virus infection. 1920 9

Intravenous (i.v.) administration of encephalitogenic peptide can effectively prevent experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis; however, the underlying cellular and molecular mechanisms are not fully understood. In this study, we induced i.v. tolerance to EAE by administration of MOG(35-55) peptide and determined the effect of this approach on intracellular signaling pathways of the IL-23/IL-17 system, which is essential for the pathogenesis of MS/EAE. In tolerized mice, phosphorylation of JAK/STAT-1, -4, ERK1/2 and NF-kappaBp65 were significantly reduced in splenocytes and the central nervous system. MOG i.v. treatment led to significantly lower production of IL-17, and administration of exogenous IL-17 slightly broke immune tolerance, which was associated with reduced activation of STAT4 and NF-kappaB. Suppressed phosphorylation of these pathway molecules was primarily evident in CD11b(+) and small numbers of CD4(+), CD8(+) and CD11c(+) cells. More importantly, adoptive transfer of CD11b(+) splenocytes of tolerized mice effectively delayed onset and reduced clinical severity of actively induced EAE. This study correlates MOG i.v. tolerance with modulation of Jak/STAT signaling pathways and investigates novel therapeutic avenues for the treatment of EAE/MS.
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PMID:MOG(35-55) i.v suppresses experimental autoimmune encephalomyelitis partially through modulation of Th17 and JAK/STAT pathways. 1922 32


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