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)

Cannabinoids are potential agents for the development of therapeutic strategies against multiple sclerosis. Here we analyzed the role of the peripheral CB(2) cannabinoid receptor in the control of myeloid progenitor cell trafficking toward the inflamed spinal cord and their contribution to microglial activation in an animal model of multiple sclerosis (experimental autoimmune encephalomyelitis, EAE). CB(2) receptor knock-out mice showed an exacerbated clinical score of the disease when compared with their wild-type littermates, and this occurred in concert with extended axonal loss, T-lymphocyte (CD4(+)) infiltration, and microglial (CD11b(+)) activation. Immature bone marrow-derived CD34(+) myeloid progenitor cells, which play a role in neuroinflammatory pathologies, were shown to express CB(2) receptors and to be abundantly recruited toward the spinal cords of CB(2) knock-out EAE mice. Bone marrow-derived cell transfer experiments further evidenced the increased contribution of these cells to microglial replenishment in the spinal cords of CB(2)-deficient animals. In line with these observations, selective pharmacological CB(2) activation markedly reduced EAE symptoms, axonal loss, and microglial activation. CB(2) receptor manipulation altered the expression pattern of different chemokines (CCL2, CCL3, CCL5) and their receptors (CCR1, CCR2), thus providing a mechanistic explanation for its role in myeloid progenitor recruitment during neuroinflammation. These findings demonstrate the protective role of CB(2) receptors in EAE pathology; provide evidence for a new site of CB(2) receptor action, namely the targeting of myeloid progenitor trafficking and its contribution to microglial activation; and support the potential use of non-psychoactive CB(2) agonists in therapeutic strategies for multiple sclerosis and other neuroinflammatory disorders.
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PMID:The CB(2) cannabinoid receptor controls myeloid progenitor trafficking: involvement in the pathogenesis of an animal model of multiple sclerosis. 1833 83

Experimental autoimmune encephalomyelitis is a T cell-mediated demyelinating disease of the CNS that serves as a model for the human disease multiple sclerosis. Increased expression of the chemokine CCL2 in the CNS has been demonstrated to be important in the development of demyelinating disease presumably by attracting inflammatory cells. However, the mechanism of how CCL2 regulates disease pathogenesis has not been fully elucidated. Using radiation bone marrow chimeric mice we demonstrated that optimum disease was achieved when CCL2 was glia derived. Furthermore, CNS production of CCL2 resulted in the accumulation of iNOS-producing CD11b(+)CD11c(+) dendritic cells and TNF-producing macrophages important for demyelination. Lack of glial-derived CCL2 production did not influence experimental autoimmune encephalomyelitis by altering either Th1 or Th17 cells, as there were no differences in these populations in the CNS or periphery between groups. These results demonstrate that the glial-derived CCL2 is important for the attraction of TNF- and iNOS-producing dendritic cells and effector macrophages to the CNS for development of subsequent autoimmune disease.
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PMID:Production of CCL2 by central nervous system cells regulates development of murine experimental autoimmune encephalomyelitis through the recruitment of TNF- and iNOS-expressing macrophages and myeloid dendritic cells. 1849 Jul 37

The central role of T cells in the induction of immunological tolerance against i.v. Ags has been well documented. However, the role of dendritic cells (DCs), the most potent APCs, in this process is not clear. In the present study, we addressed this issue by examining the involvement of two different DC subsets, CD11c(+)CD11b(+) and CD11c(+)CD8(+) DCs, in the induction of i.v. tolerance. We found that mice injected i.v. with an autoantigen peptide of myelin oligodendrocyte glycoprotein (MOG) developed less severe experimental autoimmune encephalomyelitis (EAE) following immunization with MOG peptide but presented with more CD11c(+)CD11b(+) DCs in the CNS and spleen. Upon coculturing with T cells or LPS, these DCs exhibited immunoregulatory characteristics, including increased production of IL-10 and TGF-beta but reduced IL-12 and NO; they were also capable of inhibiting the proliferation of MOG-specific T cells and enhancing the generation of Th2 cells and CD4(+)CD25(+)Foxp3(+) regulatory T cells. Furthermore, these DCs significantly suppressed ongoing EAE upon adoptive transfer. These results indicate that CD11c(+)CD11b(+) DCs, which are abundant in the CNS of tolerized animals, play a crucial role in i.v. tolerance and EAE and may be a candidate cell population for immunotherapy of autoimmune diseases.
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PMID:CD11c+CD11b+ dendritic cells play an important role in intravenous tolerance and the suppression of experimental autoimmune encephalomyelitis. 1868 39

The protein tyrosine phosphatase SHP-1 is a crucial negative regulator of cytokine signaling and inflammatory gene expression, both in the immune system and in the central nervous system (CNS). Mice genetically lacking SHP-1 (me/me) display severe inflammatory demyelinating disease following inoculation with the Theiler's murine encephalomyelitis virus (TMEV) compared to infected wild-type mice. Therefore, it became essential to investigate the mechanisms of TMEV-induced inflammation in the CNS of SHP-1-deficient mice. Herein, we show that the expression of several genes relevant to inflammatory demyelination in the CNS of infected me/me mice is elevated compared to that in wild-type mice. Furthermore, SHP-1 deficiency led to an abundant and exclusive increase in the infiltration of high-level-CD45-expressing (CD45(hi)) CD11b(+) Ly-6C(hi) macrophages into the CNS of me/me mice, in concert with the development of paralysis. Histological analyses of spinal cords revealed the localization of these macrophages to extensive inflammatory demyelinating lesions in infected SHP-1-deficient mice. Sorted populations of CNS-infiltrating macrophages from infected me/me mice showed increased amounts of viral RNA and an enhanced inflammatory profile compared to wild-type macrophages. Importantly, the application of clodronate liposomes effectively depleted splenic and CNS-infiltrating macrophages and significantly delayed the onset of TMEV-induced paralysis. Furthermore, macrophage depletion resulted in lower viral loads and lower levels of inflammatory gene expression and demyelination in the spinal cords of me/me mice. Finally, me/me macrophages were more responsive than wild-type macrophages to chemoattractive stimuli secreted by me/me glial cells, indicating a mechanism for the increased numbers of infiltrating macrophages seen in the CNS of me/me mice. Taken together, these findings demonstrate that infiltrating macrophages in SHP-1-deficient mice play a crucial role in promoting viral replication by providing abundant viral targets and contribute to increased proinflammatory gene expression relevant to the effector mechanisms of macrophage-mediated demyelination.
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PMID:Modulation of macrophage infiltration and inflammatory activity by the phosphatase SHP-1 in virus-induced demyelinating disease. 1898 38

The Idd3 genetic interval confers protection against multiple autoimmune diseases, including type 1 diabetes and experimental autoimmune encephalomyelitis. The favored candidate gene in this interval is Il2, which is polymorphic between susceptible and resistant strains of mice. IL-2 regulates the growth/death of effector T cells as well as the generation/maintenance of regulatory T cells (Tregs), and recent studies have shown that NOD.Idd3 Tregs are more suppressive than their NOD counterparts. We have further dissected the mechanisms underlying the differential suppression by NOD and NODxIdd3 Tregs and find that it is determined by CD11b(+)CD11c(-) APCs. Thus, contrary to what might be expected, our data suggest that the differential suppressive activity of NOD and NODxIdd3 Tregs is not due to an effect of the Idd3 genetic interval on T cells but rather is due to differences in the APC compartment.
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PMID:Cutting edge: the Idd3 genetic interval determines regulatory T cell function through CD11b+CD11c- APC. 1901 31

The expression of nicotinic acetylcholine receptors by neurons, microglia, and astrocytes suggests possibly diverse mechanisms by which natural nicotinic cholinergic signaling and exposure to nicotine could modulate immune responses within the CNS. In this study, we show that nicotine exposure significantly delays and attenuates inflammatory and autoimmune responses to myelin Ags in the mouse experimental autoimmune encephalomyelitis model. In the periphery, nicotine exposure inhibits the proliferation of autoreactive T cells and alters the cytokine profile of helper T cells. In the CNS, nicotine exposure selectively reduces numbers of CD11c(+) dendritic and CD11b(+) infiltrating monocytes and resident microglial cells and down-regulates the expression of MHC class II, CD80, and CD86 molecules on these cells. The results underscore roles of nicotinic acetylcholine receptors and nicotinic cholinergic signaling in inflammatory and immune responses and suggest novel therapeutic options for the treatment of inflammatory and autoimmune disorders, including those that affect the CNS.
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PMID:Nicotinic attenuation of central nervous system inflammation and autoimmunity. 1915 22

Mature myeloid cells (macrophages and CD11b(+) dendritic cells) form a prominent component of neuroinflammatory infiltrates in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). The mechanism by which these cells are replenished during relapsing and chronic neuroinflammation is poorly understood. Here we demonstrate that CD11b(+)CD62L(+)Ly6C(hi) monocytes with colony-forming potential are mobilized into the bloodstream by a granulocyte-macrophage colony-stimulating factor-dependent pathway immediately before EAE relapses. Circulating Ly6C(hi) monocytes traffic across the blood-brain barrier, up-regulate proinflammatory molecules, and differentiate into central nervous system dendritic cells and macrophages. Enrichment of Ly6C(hi) monocytes in the circulating pool is associated with an earlier onset and increased severity of clinical EAE. Our studies indicate that granulocyte-macrophage colony-stimulating factor-driven release of Ly6C(hi) precursors from the bone marrow prevents exhaustion of central nervous system myeloid populations during relapsing or chronic autoimmune demyelination, suggesting a novel pathway for therapeutic targeting.
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PMID:Circulating Ly-6C+ myeloid precursors migrate to the CNS and play a pathogenic role during autoimmune demyelinating disease. 1919 68

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

CD4 is a molecule commonly expressed on the surface of T-helper lymphocytes with a recognized critical role in the antigen presentation process that has also been reported in monocytes and macrophages, although its role in these cells remains unknown. The objective of the present study was to analyze whether experimental conditions involving a potent acquired immune component, as occurs in experimental autoimmune encephalomyelitis (EAE), are able to induce CD4 expression in the population of microglia/macrophages. Myelin Basic Protein (MBP) immunized female Lewis rats, were examined at different phases during the course of EAE according to their clinical score. Spinal cords were analyzed by flow cytometry for CD11b, CD4 and CD45, by histochemistry for NDPase and by immunohistochemistry for ED2, Iba1, CD45 and CD4. Flow cytometry analysis showed that EAE induced CD4 expression in macrophages (CD11b+/CD45(high)) and microglia (in both CD11b+/CD45(intermediate) and CD11b+/CD45(low) phenotypes). Noticeably, microglial CD4 expression was found during the recovery phase and was maintained until 40 days post-induction. In agreement, immunolabelled sections revealed CD4 expression in microglial cells with ramified morphology during the recovery and post-recovery phases. In conclusion, our results indicate that, in this EAE model, perivascular cells, microglia and macrophages showed different dynamics during the course of the disease in close relation with symptomatology and that microglial cells expressed CD4 interestingly during the recovery phase, suggesting a role of microglial CD4 expression in the resolution of the immune response.
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PMID:CD4 microglial expression correlates with spontaneous clinical improvement in the acute Lewis rat EAE model. 1924 5

Experimental autoimmune encephalomyelitis is induced in B10.PL (H-2(u)) mice by immunization with the immunodominant N-terminal epitope of myelin basic protein, Ac1-9. In the present study, we show that the site of immunization impacts disease incidence and severity. This effect is more marked in female mice than in males. Although immunization in the flanks is effective in eliciting disease, delivery of Ag in the footpad and tailbase results in poor induction. Analyses of the immune responses in female mice following different immunization regimens indicates that resistance to disease is accompanied by higher levels of IFN-gamma and CD11b(+)Gr-1(int) myeloid cells. Such myeloid cells are known to have a suppressive function, and consistent with this knowledge, blockade of IFN-gamma results in increased disease activity and decreased levels of splenic CD11b(+)Gr-1(int) cells. Conversely, injection of adjuvants (CFA or Pam(3)CSK(4)) in the footpad decreases experimental autoimmune encephalomyelitis incidence and severity. Our study indicates that the site of immunization can impact the magnitude of the ensuing inflammatory response, and that at a certain threshold a protective, regulatory circuit can be elicited.
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PMID:Autoantigen immunization at different sites reveals a role for anti-inflammatory effects of IFN-gamma in regulating susceptibility to experimental autoimmune encephalomyelitis. 1938 Jul 73


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