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Query: UMLS:C0014070 (
encephalomyelitis
)
13,017
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Interleukin-12 (IL-12) has long been considered essential in T-cell-mediated autoimmune diseases, including multiple sclerosis (MS) and its animal model, experimental autoimmune
encephalomyelitis
(EAE). This is based on the strong capacity of IL-12 to induce T-cell activation and Th1 differentiation. However, recent data have shown that the perceived central role of IL-12 in CNS inflammatory demyelination is actually due to
IL-23
, a closely related cytokine sharing the p40 subunit and the beta1 receptor chain with IL-12. There appear to be three different aspects of IL-12 involvement in EAE: (1) disease-promoting effects of exogenous IL-12, particularly in relapsing-remitting EAE and adoptive transfer EAE; (2) lack of IL-12 requirement in EAE pathogenesis, as indicated by studies in knockout mice; and (3) immunoregulatory effects of IL-12. Together, these observations make IL-12 a less attractive target for therapeutic intervention in MS.
IL-23
neutralization may be a better candidate for therapeutic intervention, and it remains to be established whether blocking
IL-23
with antibodies in adult mice will have the same effects as knocking out the
IL-23p19
gene. Current clinical trials of neutralizing anti-IL-12 antibodies in other immune-mediated diseases target the p40 subunit, thereby neutralizing both IL-12 and
IL-23
. Thus, new experimental data are expected to have important implications for therapy of human diseases.
...
PMID:Role of the IL-12/IL-23 system in the regulation of T-cell responses in central nervous system inflammatory demyelination. 1558 93
Theiler's murine
encephalomyelitis
virus (TMEV) infection of macrophages induces a demyelinating disease (DD) in certain strains of mice that is similar to human multiple sclerosis. In contrast to IFN-beta, expression of
IL-23 p19
and p40 subunits by macrophages in response to TMEV may contribute to DD. TMEV infection of macrophages likely induces
IL-23
and IFN-beta by activating p38 or ERK MAP-kinases (MAPK) and the p38 substrate ATF-2 within 30 min. To determine the role of MAPKs in TMEV-induced
IL-23
and IFN-beta expression, RAW264.7 cells were pretreated with SB203580 or U0126, inhibitors of p38 and ERK MAPKs, respectively. SB203580 significantly increased TMEV-induced p19 but decreased p40 expression. In contrast, U0126 decreased p19 and increased TMEV-induced p40 and IFN-beta expression. Interestingly, U0126 prolonged TMEV-induced ATF-2 activation to at least 3h. Thus ERK MAPKs regulate expression of TMEV-induced p19 differently than p40 and IFN-beta suggesting the benefits of U0126 in treatment of DD.
...
PMID:ERK-MAP-kinases differentially regulate expression of IL-23 p19 compared with p40 and IFN-beta in Theiler's virus-infected RAW264.7 cells. 1562 75
IL-27 (EBI3p28) is a recently discovered heterodimeric cytokine, which is functionally related to IL-23p40p19 and IL-12p40p35. IL-27 acts in synergy with IL-12 early during Th1 development from naive T cells. IL-27 functions through the WSX-1 and the gpl30 receptor subunits, which shares homology with the IL-12Rbeta2 subunit. We have previously reported that
IL-23
is up-regulated in CD11b+ microglia/macrophages in the CNS during the early phase of experimental autoimmune
encephalomyelitis
(EAE), and thus may contribute to the early induction of EAE. In the present study, we examined the expression of IL-27 and its receptor in the CNS, spleen, and lymph nodes at different stages of EAE actively induced with myelin oligodendrocyte glycoprotein peptide(35-55). Our findings show that IL-27 EBI3 and p28 mRNA were up-regulated to a maximum level at the peak of disease in APC from the CNS and lymph nodes, but not in the spleen. Moreover, IL-27 receptor (WSX-1) expression was greatly up-regulated during the early stage of EAE in both the CNS and lymph nodes. Taken together, our data show that subunits of IL-27 and its receptor (WSX-1) mRNAs are markedly up-regulated in inflammatory cells in the CNS at the peak of disease. Thus, IL-27 produced by infiltrating cells in the CNS may regulate in a paracrine manner the Th1 response in EAE.
...
PMID:IL-27 subunits and its receptor (WSX-1) mRNAs are markedly up-regulated in inflammatory cells in the CNS during experimental autoimmune encephalomyelitis. 1585 May 76
Interleukin-12 (IL-12, p70) a heterodimeric cytokine of p40 and p35 subunits, important for Th1-type immune responses, has been attributed a prominent role in multiple sclerosis (MS) and its animal model, experimental autoimmune
encephalomyelitis
(EAE). Recently, the related heterodimeric cytokine,
IL-23
, composed of the same p40 subunit as IL-12 and a unique p19 subunit, was shown to be involved in Th1 responses and EAE. We investigated whether astrocytes and microglia, CNS cells with antigen-presenting cell (APC) function can present antigen to myelin basic protein (MBP)-reactive T cells, and whether this presentation is blocked with antibodies against IL-12/IL-23p40. Interferon (IFN)-gamma-treated APC induced proliferation of MBP-reactive T cells. Anti-IL-12/IL-23p40 antibodies blocked this proliferation. These results support and extend our previous observation that astrocytes and microglia produce IL-12/IL-23p40. Moreover, we show that stimulated astrocytes and microglia produce biologically active IL-12p70. Because IL-12 and
IL-23
share p40, we wanted to determine whether astrocytes also express IL-12p35 and
IL-23p19
, as microglia were already shown to express them. Astrocytes expressed IL-12p35 mRNA constitutively, and
IL-23 p19
after stimulation. Thus, astrocytes, under inflammatory conditions, express all subunits of IL-12/
IL-23
. Their ability to present antigen to encephalitogenic T cells can be blocked by neutralizing anti-IL-12/IL-23p40 antibodies.
...
PMID:Astrocytes as antigen-presenting cells: expression of IL-12/IL-23. 1608 89
Experimental autoimmune
encephalomyelitis
is the prototypic T cell-mediated autoimmune disease model. Classically, this disease was viewed in terms of type 1 versus type 2 immunity: the type 1 cytokines IFNgamma and TNFalpha promoting disease, whereas an IL-4-dominated, type 2 response was protective. However, studies in knockout mice do not support this paradigm. More recent data point to important roles for
IL-23
and IL-17 (rather than IL-12 and IFNgamma) in the establishment and persistence of the inflammatory lesion. IL-10 appears to be the dominant cytokine mediating recovery. The source of IL-10 includes B cells (most probably in the peripheral lymphoid organs). However, the key IL-10-producing cell within the central nervous system is a CD4+CD25+ T cell population that has regulatory function and is critical to resolution of the disease.
...
PMID:Cytokines in the induction and resolution of experimental autoimmune encephalomyelitis. 1615 54
Interleukin (IL)-23 is a heterodimeric cytokine closely related to IL-12. Yet, despite a strong structural relationship that includes a shared p40 subunit, this does not translate into functional similarity. In fact, the opposite is true, in that these two cytokines appear to have profoundly different roles in regulating host immune responses. It is now clear that
IL-23
has key roles in autoimmune destruction in experimental allergic
encephalomyelitis
, collagen-induced arthritis and inflammatory bowel disease.
IL-23
drives the development of autoreactive IL-17-producing T cells and promotes chronic inflammation dominated by IL-17, IL-6, IL-8 and tumor necrosis factor as well as neutrophils and monocytes. It is unlikely that
IL-23
and its downstream effects evolved just to cause autoimmunity, but its real benefit to the host and the lineage relationship between IL-17-producing cells and T helper 1 cells remain unclear. By comparing the pathophysiological function of IL-12 and
IL-23
in the context of host defense and autoimmune inflammation, we are beginning to understand the novel
IL-23
-IL-17 immune pathway.
...
PMID:Understanding the IL-23-IL-17 immune pathway. 1629 Feb 28
Experimental autoimmune
encephalomyelitis
(EAE) is widely regarded as an animal model of the human disease multiple sclerosis. A multitude of studies has investigated the neuroantigen-specific T-cell mediated cytokine pattern present in animals with EAE. In particular, the role of the so-called Th1- and Th2-cytokines has been addressed. In a recent study, it has been demonstrated that
IL-23
rather than IL-12 is critical for modulating the character of the developing immune response towards a proinflammatory response and leading to EAE. IL-17 is a crucial effector cytokine, whose production is specifically triggered by
IL-23
, and it has been shown to be an essential inflammatory mediator in other autoimmune diseases and inflammatory conditions. This led us to investigate the role of IL-17 in EAE. Strong antigen-specific production of IL-17 was demonstrated both in peripheral immune organs and in the CNS in acute and chronic EAE, as demonstrated by ELISPOT and RT-PCR analysis. Therapeutic neutralization of IL-17 with IL-17-receptor-Fc-protein in acute EAE ameliorated clinical symptoms. Neutralization of IL-17 with a monoclonal antibody also ameliorated the disease course. We conclude that IL-17 is crucially involved in the cytokine network as an effector cytokine in EAE.
...
PMID:Therapeutic efficacy of IL-17 neutralization in murine experimental autoimmune encephalomyelitis. 1638 39
IL-23
is regarded as a major pro-inflammatory mediator in autoimmune disease, a role which until recently was ascribed to its related cytokine IL-12.
IL-23
, an IL-12p40/p19 heterodimeric protein, binds to IL-12Rbeta1/IL-23R receptor complexes. Mice deficient for p19, p40 or IL-12Rbeta1 are resistant to experimental autoimmune
encephalomyelitis
or collagen-induced arthritis. Paradoxically, however, IL-12Rbeta2- and IL-12p35-deficient mice show remarkable increases in disease susceptibility, suggesting divergent roles of
IL-23
and IL-12 in modulating inflammatory processes.
IL-23
induces IL-17, which mediates inflammation and tissue remodeling, but the role of IL-12 in this respect remains unidentified. We investigated the roles of exogenous (recombinant) and endogenous (macrophage-derived) IL-12 and
IL-23
, on IL-17-induction in human T-cells.
IL-23
enhanced IL-17 secretion, as did IL-2, IL-15, IL-18 and IL-21. In contrast, IL-12 mediated specific inhibition of IL-17 production. These data support the role of
IL-23
in inflammation through stimulating IL-17 production by T lymphocytes, and importantly indicate a novel regulatory function for IL-12 by specifically suppressing IL-17 secretion. These data therefore extend previous reports that had indicated unique functions for
IL-23
and IL-12 due to distinct receptor expression and signal transduction complexes, and provide novel insights into the regulation of immunity, inflammation and immunopathology.
...
PMID:Divergent effects of IL-12 and IL-23 on the production of IL-17 by human T cells. 1648 11
Interleukin-23 (IL-23) is a heterodimeric cytokine that is composed of a p40 subunit, shared with the closely related cytokine IL-12, and a smaller
IL-23p19
subunit. It belongs to a family of heterodimeric cytokines that also includes IL-12 and IL-27. Experimental autoimmune
encephalomyelitis
(EAE) is an autoimmune disease that serves as a model for multiple sclerosis, an inflammatory demyelinating disease of the central nervous system that is a frequent cause of disability in young adults. EAE is thought to be initiated by CD4+ T cells. The production of interferon-gamma and tumor necrosis factor-alpha (T helper 1 [Th1] phenotype) was considered a marker for the ability of such cells to induce disease. Consistent with this view, IL-12, a cytokine that induces the differentiation of Th1 cells, was considered essential for EAE susceptibility. However, it is now clear that IL-23 rather than IL-12 is required for EAE susceptibility. IL-23 induces a population of IL-17-producing cells that is more critically involved in EAE pathogenesis than Th1 cells. Here, we review the role of the IL-23 system in the pathophysiology of EAE.
...
PMID:Pathophysiology of interleukin-23 in experimental autoimmune encephalomyelitis. 1662 62
It was recently demonstrated that interleukin (IL)-23-driven IL-17-producing (ThIL-17) T cells mediate inflammatory pathology in certain autoimmune diseases. We show that the induction of antigen-specific ThIL-17 cells, but not T helper (Th)1 or Th2 cells, by immunization with antigens and adjuvants is abrogated in IL-1 receptor type I-deficient (IL-1RI(-/-)) mice. Furthermore, the incidence of experimental autoimmune
encephalomyelitis
(EAE) was significantly lower in IL-1RI(-/-) compared with wild-type mice, and this correlated with a failure to induce autoantigen-specific ThIL-17 cells, whereas induction of Th1 and Th2 responses was not substantially different. However, EAE was induced in IL-1RI(-/-) mice by adoptive transfer of autoantigen-specific cells from wild-type mice with EAE.
IL-23
alone did not induce IL-17 production by T cells from IL-1RI(-/-) mice, and
IL-23
-induced IL-17 production was substantially enhanced by IL-1alpha or IL-1beta, even in the absence of T cell receptor stimulation. We demonstrate essential roles for phosphatidylinositol 3-kinase, nuclear factor kappaB, and novel protein kinase C isoforms in IL-1- and
IL-23
-mediated IL-17 production. Tumor necrosis factor alpha also synergized with
IL-23
to enhance IL-17 production, and this was IL-1 dependent. Our findings demonstrate that IL-1 functions upstream of IL-17 to promote pathogenic ThIL-17 cells in EAE.
...
PMID:A crucial role for interleukin (IL)-1 in the induction of IL-17-producing T cells that mediate autoimmune encephalomyelitis. 1681 75
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