myelin-oligodendrocyte-glycoprotein-(35-55) and Inflammation

Macrophages are highly plastic, key regulators of inflammation. Deregulation of macrophage activation can lead to excessive inflammation as seen in inflammatory disorders like atherosclerosis, obesity, multiple sclerosis and sepsis. Targeting intracellular metabolism is considered as an approach to reshape deranged macrophage activation and to dampen the progression of inflammatory disorders. ATP citrate lyase (Acly) is a key metabolic enzyme and an important regulator of macrophage activation. Using a macrophage-specific Acly-deficient mouse model, we investigated the role of Acly in macrophages during acute and chronic inflammatory disorders. First, we performed RNA sequencing to demonstrate that Acly-deficient macrophages showed hyperinflammatory gene signatures in response to acute LPS stimulation

Topics: Animals; ATP Citrate (pro-S)-Lyase; Cells, Cultured; Cytokines; Diet, High-Fat; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Inflammation Mediators; Lipopolysaccharides; Macrophages; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Obesity; Peptide Fragments; Peritonitis; Phenotype; Signal Transduction

Experimental autoimmune encephalomyelitis (EAE) is an animal disease model of multiple sclerosis (MS) that involves the immune system and central nervous system (CNS). However, it is unclear how genetic predispositions promote neuroinflammation in MS and EAE. Here, we investigated how partial loss-of-function of suppressor of MEK1 (SMEK1), a regulatory subunit of protein phosphatase 4, facilitates the onset of MS and EAE.. C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein 35-55 (MOG. Here, we showed that partial Smek1 deficiency caused more severe symptoms in the EAE model than in controls by activating myeloid cells and that Smek1 was required for maintaining immunosuppressive function by modulating the indoleamine 2,3-dioxygenase (IDO1)-aryl hydrocarbon receptor (AhR) pathway. Single-cell sequencing and an in vitro study showed that Smek1-deficient microglia and macrophages were preactivated at steady state. After MOG. The present study suggests a protective role of Smek1 in autoimmune demyelination pathogenesis via immune suppression and inflammation regulation in both the immune system and the central nervous system. Our findings provide an instructive basis for the roles of Smek1 in EAE and broaden the understanding of the genetic factors involved in the pathogenesis of autoimmune demyelination.

Topics: Animals; Central Nervous System; Cytokines; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Gene Knockout Techniques; Indoleamine-Pyrrole 2,3,-Dioxygenase; Inflammation; Interferon-gamma; Mice; Mice, Inbred C57BL; Microglia; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Myeloid Cells; Peptide Fragments; Phosphoprotein Phosphatases; Receptors, Aryl Hydrocarbon; Signal Transduction; Spleen

Multiple sclerosis (MS) is known as an autoimmune disease in the central nervous system (CNS) characterized by motor deficits, pain, fatigue, cognitive impairment, and sensory and visual dysfunction. MS is considered to be resulted from significant inflammatory response. Paricalcitol (Pari) is a vitamin D2 analogue, which has been indicated to show anti-inflammatory activities in kidney and heart diseases. In the present study, if Pari could ameliorate the experimental autoimmune encephalomyelitis (EAE) was investigated. Here, the C57BL/6 mice were immunized using myelin oligodendrocyte glycoprotein 35-55 (MOG

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Calcium-Binding Proteins; Caspase 3; Cell Line; Cell Proliferation; Cyclooxygenase 2; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Ergocalciferols; Glial Fibrillary Acidic Protein; Humans; I-kappa B Proteins; Inflammation; Jurkat Cells; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Inbred C57BL; Microfilament Proteins; Microglia; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; NF-kappa B; Nitric Oxide Synthase Type II; Peptide Fragments; Poly (ADP-Ribose) Polymerase-1; Primary Cell Culture; RAW 264.7 Cells; Signal Transduction; Spinal Cord

Tim-1, a phosphatidylserine receptor expressed on B cells, induces interleukin 10 (IL-10) production by sensing apoptotic cells. Here we show that mice with B cell-specific Tim-1 deletion develop tissue inflammation in multiple organs including spontaneous paralysis with inflammation in the central nervous system (CNS). Transcriptomic analysis demonstrates that besides IL-10, Tim-1

Topics: Aging; Animals; B-Lymphocytes; Encephalomyelitis, Autoimmune, Experimental; Hepatitis A Virus Cellular Receptor 1; Immunomodulation; Inflammation; Interleukin-10; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Organ Specificity; Peptide Fragments; Receptors, Immunologic

The experimental autoimmune encephalomyelitis (EAE) is a model that mimics multiple sclerosis in rodents. Evidence has suggested that the activation of indoleamine-2,3-dioxygenase (IDO), the rate-limiting enzyme in the kynurenine pathway (KP), plays a crucial role in inflammation-related diseases. The present study aimed to investigate the involvement of the inflammatory process and KP components in a model of EAE in mice. To identify the role of KP in EAE pathogenesis, mice received IDO inhibitor (INCB024360) at a dose of 200 mg/kg (per oral) for 25 days. We demonstrated that IDO inhibitor mitigated the clinical signs of EAE, in parallel with the reduction of cytokine levels (brain, spinal cord, spleen and lymph node) and ionized calcium-binding adaptor protein-1 (Iba-1) gene expression in the central nervous system of EAE mice. Besides, IDO inhibitor causes a significant decrease in the levels of tryptophan, kynurenine and neurotoxic metabolites of KP, such as 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) in the prefrontal cortex, hippocampus, spinal cord, spleen and lymph node of EAE mice. The mRNA expression and enzyme activity of IDO and kynurenine 3-monooxygenase (KMO) were also reduced by IDO inhibitor. These findings indicate that the inflammatory process concomitant with the activation of IDO/KP is involved in the pathogenic mechanisms of EAE. The modulation of KP is a promising target for novel pharmacological treatment of MS.

Topics: Animals; Body Weight; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Enzyme Inhibitors; Female; Gene Expression; Indoleamine-Pyrrole 2,3,-Dioxygenase; Inflammation; Kynurenine; Kynurenine 3-Monooxygenase; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Oximes; Peptide Fragments; Quinolinic Acid; Sulfonamides; Tryptophan

The active experimental autoimmune encephalomyelitis (EAE) model is often initiated using myelin oligodendrocyte glycoprotein (MOG) immunization followed by pertussis toxin (PTX) to study multiple sclerosis. However, PTX inactivates G protein-coupled receptors, and with increasing knowledge of the role that various G protein-coupled receptors play in immune homeostasis, it is valuable to establish neuroimmune endpoints for active EAE without PTX.. Female C57BL/6 mice were immunized with MOG35-55 peptide in Complete Freund's Adjuvant and neuroinflammation, including central nervous system B-cell infiltration, was compared to saline-injected mice. Since it was anticipated that disease onset would be slower and less robust than EAE in the presence of PTX, both cervical and lumbosacral sections of the spinal cord were evaluated.. Immunohistochemical analysis showed that EAE without PTX induced immune infiltration, CCL2 and VCAM-1 upregulation. Demyelination in the cervical region correlated with the infiltration of CD19+ B cells in the cervical region. There was upregulation of IgG, CD38, and PDL1 on B cells in cervical and lumbosacral regions of the spinal cord in EAE without PTX. Interestingly, IgG was expressed predominantly by CD19- cells.. These data demonstrate that many neuroimmune endpoints are induced in EAE without PTX and although clinical disease is mild, this can be used as an autoimmune model when PTX inactivation of G protein-coupled receptors is not desired.

Topics: Adjuvants, Immunologic; Animals; B-Lymphocytes; Encephalomyelitis, Autoimmune, Experimental; Female; Inflammation; Lumbosacral Region; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Pertussis Toxin; Phenotype; Spinal Cord

Leukocyte trafficking is a key event during autoimmune and inflammatory responses. The subarachnoid space (SAS) and cerebrospinal fluid are major routes for the migration of encephalitogenic T cells into the central nervous system (CNS) during experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, and are sites of T cell activation before the invasion of CNS parenchyma. In particular, autoreactive Th1 and Th17 cell trafficking and reactivation in the CNS are required for the pathogenesis of EAE. However, the molecular mechanisms controlling T cell dynamics during EAE are unclear. We used two-photon laser microscopy to show that autoreactive Th1 and Th17 cells display distinct motility behavior within the SAS in the spinal cords of mice immunized with the myelin oligodendrocyte glycoprotein peptide MOG

Topics: Animals; Cell Movement; Central Nervous System; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Gene Expression Profiling; Humans; Inflammation; Lymphocyte Activation; Lymphocyte Function-Associated Antigen-1; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Confocal; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Spinal Cord; Th1 Cells; Th17 Cells

Topics: Animals; Anti-Inflammatory Agents; Astragalus propinquus; B7-H1 Antigen; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Female; Inflammation; Mice; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Phytotherapy; Plant Gums; Programmed Cell Death 1 Ligand 2 Protein; Programmed Cell Death 1 Receptor; RNA, Messenger; Signal Transduction; Spinal Cord; T-Lymphocyte Subsets; Up-Regulation

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces cell apoptosis by transducing apoptosis signals after interacting with its receptor (TRAIL-R). Although the actual biological role of TRAIL remains to be elucidated, recent accumulating evidence implies that TRAIL regulates immune responses and immune cell homeostasis. TRAIL was administered to mice to induce experimental autoimmune encephalomyelitis (EAE), and to evaluate its impact on neuroinflammation and disease activity. The effects of TRAIL on neuroantigen [myelin oligodendrocyte glycoprotein (MOG). TRAIL/TRAIL-R interaction regulates CD4

Topics: Adoptive Transfer; Animals; Apoptosis; CD4-Positive T-Lymphocytes; Cell Proliferation; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Female; Gene Expression Profiling; Homeodomain Proteins; Inflammation; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, Antigen, T-Cell; Receptors, TNF-Related Apoptosis-Inducing Ligand; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand

Voltage-gated calcium channels (VGCCs) play a critical role in neuroinflammatory diseases, such as multiple sclerosis (MS). CTK 01512-2 is a recombinant version of the peptide Phα1β derived from the spider Phoneutria nigriventer, which inhibits N-type VGCC/TRPA1-mediated calcium influx. We investigated the effects of this molecule in the mouse model of experimental autoimmune encephalomyelitis (EAE). The effects of CTK 01512-2 were compared to those displayed by ziconotide-a selective N-type VGCC blocker clinically used for chronic pain-and fingolimod-a drug employed for MS treatment. The intrathecal (i.t.) treatment with CTK 01512-2 displayed beneficial effects, by preventing nociception, body weight loss, splenomegaly, MS-like clinical and neurological scores, impaired motor coordination, and memory deficits, with an efficacy comparable to that observed for ziconotide and fingolimod. This molecule displayed a favorable profile on EAE-induced neuroinflammatory changes, including inflammatory infiltrate, demyelination, pro-inflammatory cytokine production, glial activation, and glucose metabolism in the brain and spinal cord. The recovery of spatial memory, besides a reduction of serum leptin levels, allied to central and peripheral elevation of the anti-inflammatory cytokine IL-10, was solely modulated by CTK 01512-2, dosed intrathecally. The intravenous (i.v.) administration of CTK 01512-2 also reduced the EAE-elicited MS-like symptoms, similarly to that seen in animals that received fingolimod orally. Ziconotide lacked any significant effect when dosed by i.v. route. Our results indicate that CTK 01512-2 greatly improved the neuroinflammatory responses in a mouse model of MS, with a higher efficacy when compared to ziconotide, pointing out this molecule as a promising adjuvant for MS management.

Topics: Animals; Anti-Inflammatory Agents; Calcium Channel Blockers; Chemokines; Cognition Disorders; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Fingolimod Hydrochloride; Hyperalgesia; Inflammation; Inflammation Mediators; Injections, Spinal; Mice, Inbred C57BL; Motor Activity; Multiple Sclerosis; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; Nociception; omega-Conotoxins; Peptide Fragments

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system (CNS). Currently, there is still lack of curative treatment for MS. Mesenchymal stem cell- (MSC-) based therapy is recently the subject of intense interest in autoimmune diseases. Here, we investigated the therapeutic effect and potential mechanism of human amnion mesenchymal cells (hAMC) on inflammation and remyelination in experimental autoimmune encephalomyelitis (EAE) mice. C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein (MOG) 35-55 peptide. hAMC were injected intraperitoneal when EAE was successfully established. The results demonstrated that application of hAMC significantly ameliorated the disease severity and histopathological changes in EAE mice. The production of proinflammatory cytokines such as IFN-

Topics: Animals; Cells, Cultured; Chronic Disease; Cytokines; Disease Models, Animal; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Humans; Inflammation; Inflammation Mediators; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Neurons; Peptide Fragments; Wound Healing

V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA) is a negative checkpoint regulator (NCR) involved in inhibition of T cell-mediated immunity. Expression changes of other NCRs (PD-1, PD-L1/L2, CTLA-4) during inflammation of the central nervous system (CNS) were previously demonstrated, but VISTA expression in the CNS has not yet been explored. Here, we report that in the human and mouse CNS, VISTA is most abundantly expressed by microglia, and to lower levels by endothelial cells. Upon TLR stimulation, VISTA expression was reduced in primary neonatal mouse and adult rhesus macaque microglia in vitro. In mice, microglial VISTA expression was reduced after lipopolysaccharide (LPS) injection, during experimental autoimmune encephalomyelitis (EAE), and in the accelerated aging Ercc1

Topics: Animals; Animals, Newborn; Brain; Calcium-Binding Proteins; Cells, Cultured; Central Nervous System Diseases; Disease Models, Animal; DNA-Binding Proteins; Endonucleases; Female; Freund's Adjuvant; Gene Expression; Humans; Inflammation; Lipopolysaccharides; Macaca mulatta; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microfilament Proteins; Microglia; Myelin-Oligodendrocyte Glycoprotein; Nerve Tissue Proteins; Peptide Fragments

In this study, we investigated the uptake of malondialdehyde (MDA)-modified myelin oligodendrocyte glycoprotein (MOG) in the context of lipid peroxidation and its implications in CNS autoimmunity. The use of custom-produced fluorescently labeled versions of MOG or MDA-modified MOG enabled us to study and quantify the uptake by different macrophage populations and to identify the responsible receptor, namely SRA. The SRA-mediated uptake of MDA-modified MOG is roughly tenfold more efficient compared to that of the native form. Notably, this uptake is most strongly associated with anti-inflammatory M2-type macrophages. MDA-modified MOG was demonstrated to be resistant to degradation by lysine-dependent proteases in vitro, but the overall digestion fragments appeared to be similar in cell lysates, although their relative abundance appeared to be altered as a result of faster uptake. Accordingly, MDA-modified MOG is processed for presentation by APCs, allowing maximized recall proliferation of MOG

Topics: Animals; Autoantigens; Cells, Cultured; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Lipid Peroxidation; Lymphocyte Activation; Macrophages; Malondialdehyde; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Peptide Hydrolases; Proteolysis; RAW 264.7 Cells; Receptors, Antigen, T-Cell; Recombinant Proteins; Scavenger Receptors, Class A; T-Lymphocytes

Experimental autoimmune encephalomyelitis (EAE) induced by active immunization of C57BL/6 mice with peptide from myelin oligodendrocyte protein (MOG

Topics: Animals; Cervical Vertebrae; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Gene Expression; Inflammation; Leukocytes; Lumbar Vertebrae; Meninges; Mice, Inbred C57BL; Microvessels; Myelin-Oligodendrocyte Glycoprotein; Parenchymal Tissue; Peptide Fragments; Spinal Cord

Semaphorin 7A (sema7A) is classified as an immune semaphorin with dual functions in the immune system and in the central nervous system (CNS). These molecules are of interest due to their potential role in multiple sclerosis (MS), which is a chronic demyelinating and neurodegenerative disease of autoimmune origin. In this study, we elucidated the role of sema7A in neuroinflammation using both in vitro and in vivo experimental models. In an in vitro model of neuroinflammation, using cerebellar organotypic slice cultures, we observed that challenge with lipopolysaccharide (LPS) endotoxin did not affect demyelination or cell death in sema7A-deficient cultures compared to wild-type cultures. Moreover, the in vivo outcome of experimental autoimmune encephalomyelitis (EAE) in sema7A-deficient mice was altered in an antigen- and adjuvant-dose-dependent manner, while no differences were observed in the wild-type counterparts. Altogether, these results indicate that sema7A is involved in peripheral immunity and CNS inflammation in MS pathogenesis. Indeed, these data suggest that sema7A might be a potential therapeutic target to treat MS and autoimmune conditions.

Topics: Adjuvants, Immunologic; Animals; Antigens, CD; Cell Proliferation; Cerebellum; Disease Susceptibility; Encephalomyelitis, Autoimmune, Experimental; Immunization; Inflammation; Mice, Inbred C57BL; Mice, Knockout; Models, Biological; Molecular Targeted Therapy; Multiple Sclerosis; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; Nerve Degeneration; Peptide Fragments; Semaphorins

Chemokine (CC motif) receptor-like 2 is a 7-transmembrane protein related to the family of the atypical chemokine receptors, which are proteins devoid of chemotactic activity and involved in the control of inflammation. Experimental autoimmune encephalitis is an autoimmune disorder that replicates the inflammatory aspects of multiple sclerosis. Chemokine (CC motif) receptor-like 2-deficient mice developed exacerbated, nonresolving disease with protracted inflammatory response and increased demyelination. The increased severity of the disease was associated with higher levels of microglia/macrophage activation markers and imbalanced M1/M2 polarization. Thus, chemokine (CC motif) receptor-like 2 is involved in the downregulation of central nervous system-associated experimental autoimmune encephalitis inflammation in the recovery phase of the disease. Therefore chemokine (CC motif) receptor-like 2 should be considered to be a molecule involved in the regulation of the inflammatory response associated with multiple sclerosis.

Topics: Animals; Antigens; Cell Polarity; Cell Proliferation; Central Nervous System; Cross-Priming; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Immunization; Inflammation; Interferon-gamma; Macrophages; Mice, Inbred C57BL; Mice, Knockout; Microglia; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, CCR; Receptors, Chemokine; T-Lymphocytes

In the present study we examined the role of thymic stromal lymphopoietin (TSLP) in experimental autoimmune encephalomyelitis (EAE). Here, we report that TSLP knock-out (KO) mice display a delayed onset of disease and an attenuated form of EAE. This delayed onset was accompanied by a reduced number of encephalitogenic T helper type 1 (Th1) cells in the central nervous system (CNS) of TSLP KO mice. In addition, CD4(+) and CD8(+) T cells from CNS of TSLP KO mice show a reduced activation status in comparison to wild-type mice. It is noteworthy that we could also show that lymph node cells from TSLP KO mice expanded less efficiently and that interleukin (IL)-6-, interferon (IFN)-γ and tumour necrosis factor (TNF)-α levels were reduced. Furthermore, CD3(+) T cells isolated in the preclinical phase from myelin oligodendrocyte glycoprotein peptide 35-55 (MOG(35-55))-immunized TSLP KO mice showed a reduced response after secondary exposure to MOG(35-55), indicating that differentiation of naive T cells into MOG(35-55)-specific effector and memory T cells was impaired in KO mice. The addition of recombinant TSLP enhanced T cell proliferation during MOG(35-55) restimulation, showing that T cells also respond directly to TSLP. In summary, these data demonstrate that expression of, and immune activation by, TSLP contributes significantly to the immunopathology of EAE.

Topics: Animals; Bone Marrow Cells; CD8-Positive T-Lymphocytes; Cell Proliferation; Cells, Cultured; Central Nervous System; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Interferon-gamma; Interleukin-6; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Th1 Cells; Thymic Stromal Lymphopoietin; Tumor Necrosis Factor-alpha

Nicotine has been shown to attenuate experimental autoimmune encephalomyelitis (EAE) through inhibiting inflammation in microglial populations during the disease course. In this study, we investigated whether nicotine modified the regenerative process in EAE by examining nestin-expressing neural stem cells (NSCs) in the spinal cord, which is the primary area of demyelination and inflammation in EAE. Our results show that the endogenous neurogenic responses in the spinal cord after EAE are limited and delayed: while nestin expression is increased, the proliferation of ependymal cells is inhibited compared to healthy animals. Nicotine application significantly reduced nestin expression and partially allowed for the proliferation of ependymal cells. We found that reduction of ependymal cell proliferation correlated with inflammation in the same area, which was relieved by the administration of nicotine. Further, increased numbers of oligodendrocytes (OLs) were observed after nicotine treatment. These findings give a new insight into the mechanism of how nicotine functions to attenuate EAE.

Topics: Animals; Antigens; Autophagy-Related Proteins; Doublecortin Domain Proteins; Encephalomyelitis, Autoimmune, Experimental; Glial Fibrillary Acidic Protein; Inflammation; Intracellular Signaling Peptides and Proteins; Ki-67 Antigen; Leukocyte Common Antigens; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Myelin-Oligodendrocyte Glycoprotein; Nerve Degeneration; Nestin; Neural Stem Cells; Neurogenesis; Neuropeptides; Nicotine; Nicotinic Agonists; Peptide Fragments; Proteoglycans; Spinal Cord; Time Factors

Foxp3(+) regulatory T cell (Treg)-based immunotherapy holds promise for autoimmune diseases. However, this effort has been hampered by major caveats, including the low frequency of autoantigen-specific Foxp3(+) Tregs and lack of understanding of their molecular and cellular targets, in an unmanipulated wild-type (WT) immune repertoire. In this study, we demonstrate that infusion of myelin in WT mice results in the de novo induction of myelin-specific Foxp3(+) Tregs in WT mice and amelioration of experimental autoimmune encephalomyelitis. Myelin-specific Foxp3(+) Tregs exerted their effect both by diminishing Ag-bearing inflammatory dendritic cell (iDC) recruitment to lymph nodes and by impairing their function. Transcriptome analysis of ex vivo-isolated Treg-exposed iDCs showed significant enrichment of transcripts involved in functional properties of iDCs, including chemotaxis-related genes. To this end, CCR7 expression by iDCs was significantly downregulated in tolerant mice and this was tightly regulated by the presence of IL-10. Collectively, our data demonstrate a novel model for deciphering the Ag-specific Foxp3(+) Treg-mediated mechanisms of tolerance and delineate iDCs as a Foxp3(+) Treg cellular target in unmanipulated mice.

Topics: Animals; Autoantigens; Autoimmunity; Chemotaxis; Cluster Analysis; Dendritic Cells; Disease Models, Animal; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Forkhead Transcription Factors; Gene Expression Profiling; Immune Tolerance; Inflammation; Interleukin-10; Lymph Nodes; Lymphocyte Depletion; Mice; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, CCR7; Signal Transduction; T-Cell Antigen Receptor Specificity; T-Lymphocytes, Regulatory

DRα1-mouse(m)MOG-35-55, a novel construct developed in our laboratory as a simpler and potentially less immunogenic alternative to two-domain class II constructs, was shown previously to target the MIF/CD74 pathway and to reverse clinical and histological signs of experimental autoimmune encephalomyelitis (EAE) in DR*1501-Tg mice in a manner similar to the parent DR2β1-containing construct.. In order to determine whether DRα1-mMOG-35-55 could treat EAE in major histocompatibility complex (MHC)-mismatched mice and to evaluate the treatment effect on central nervous system (CNS) inflammation, C57BL/6 mice were treated with DRα1-mMOG-35-55. In addition, gene expression profile was analyzed in spinal cords of EAE DR*1501-Tg mice that were treated with DRα1-mMOG-35-55.. We here demonstrate that DRα1-mMOG-35-55 could effectively treat EAE in MHC-mismatched C57BL/6 mice by reducing CNS inflammation, potentially mediated in part through an increased frequency of M2 monocytes in the spinal cord. Microarray analysis of spinal cord tissue from DRα1-mMOG-35-55-treated vs. vehicle control mice with EAE revealed decreased expression of a large number of pro-inflammatory genes including CD74, NLRP3, and IL-1β and increased expression of genes involved in myelin repair (MBP) and neuroregeneration (HUWE1).. These findings indicate that the DRα1-mMOG-35-55 construct retains therapeutic, anti-inflammatory, and neuroprotective activities during treatment of EAE across MHC disparate barriers.

Topics: Animals; CD11 Antigens; Cell Count; Cell Survival; Central Nervous System Diseases; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; HLA-DR alpha-Chains; Inflammation; Lectins, C-Type; Macrophages; Male; Mannose Receptor; Mannose-Binding Lectins; Mice; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Nerve Regeneration; Neuroprotection; Neuroprotective Agents; Peptide Fragments; Receptors, Cell Surface

Astrocytes respond to insult with a process of cellular activation known as reactive astrogliosis. One of the key signals regulating this phenomenon is the transcription factor nuclear factor-kappa B (NF-κB), which is responsible for modulating inflammation, cell survival, and cell death. In astrocytes, following trauma or disease, the expression of NF-κB-dependent genes is highly activated. We previously demonstrated that inactivation of astroglial NF-κB in vivo (GFAP-IκBα-dn mice) leads to improved functional outcome in experimental autoimmune encephalomyelitis (EAE), and this is accompanied by reduction of pro-inflammatory gene expression in the CNS. Here we extend our studies to show that recovery from EAE in GFAP-IκBα-dn mice is associated with reduction of peripheral immune cell infiltration into the CNS at the chronic phase of EAE. This is not dependent on a less permeable blood-brain barrier, but rather on a reduced immune cell mobilization from the periphery. Furthermore, once inside the CNS, the ability of T cells to produce pro-inflammatory cytokines is diminished during acute disease. In parallel, we found that the number of total and activated microglial cells is reduced, suggesting that functional improvement in GFAP-IκBα-dn mice is dependent upon reduction of the overall inflammatory response within the CNS sustained by both resident and infiltrating cells. This results in preservation of myelin compaction and enhanced remyelination, as shown by electron microscopy analysis of the spinal cord. Collectively our data indicate that astrocytes are key players in driving CNS inflammation and are directly implicated in the pathophysiology of EAE, since blocking their pro-inflammatory capability results in protection from the disease.

Topics: Animals; Astrocytes; Central Nervous System; Claudin-5; Cytokines; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Gene Expression Regulation; Glial Fibrillary Acidic Protein; I-kappa B Proteins; Immunoglobulin G; Inflammation; Leukocytes; Mice; Mice, Transgenic; Microscopy, Electron; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; NF-KappaB Inhibitor alpha; Peptide Fragments; Spinal Cord; T-Lymphocytes

Multiple sclerosis (MS) is a chronic demyelinating immune mediated disease of the central nervous system. The immunoproteasome is a distinct class of proteasomes found predominantly in monocytes and lymphocytes. Recently, we demonstrated a novel function of immunoproteasomes in cytokine production and T cell differentiation. In this study, we investigated the therapeutic efficacy of an inhibitor of the immunoproteasome (ONX 0914) in two different mouse models of MS. ONX 0914 attenuated disease progression after active and passive induction of experimental autoimmune encephalomyelitis (EAE), both in MOG₃₅-₅₅ and PLP₁₃₉₋₁₅₁-induced EAE. Isolation of lymphocytes from the brain or spinal cord revealed a strong reduction of cytokine-producing CD4(+) cells in ONX 0914 treated mice. Additionally, ONX 0914 treatment prevented disease exacerbation in a relapsing-remitting model. An analysis of draining lymph nodes after induction of EAE revealed that the differentiation to Th17 or Th1 cells was strongly impaired in ONX 0914 treated mice. These results implicate the immunoproteasome in the development of EAE and suggest that immunoproteasome inhibitors are promising drugs for the treatment of MS.

Topics: Animals; Brain; Cell Differentiation; Disease Models, Animal; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Inflammation; Mice; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Oligopeptides; Peptide Fragments; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Spinal Cord; T-Lymphocytes

The adoptive transfer of myelin-reactive T cells into wild-type hosts results in spinal cord inflammation and ascending paralysis, referred to as conventional experimental autoimmune encephalomyelitis (EAE), as opposed to brainstem inflammation and ataxia, which characterize disease in IFN-γRKO hosts (atypical EAE). In this article, we show that atypical EAE correlates with preferential upregulation of CXCL2 in the brainstem, and is driven by CXCR2-dependent recruitment of neutrophils. In contrast, conventional EAE is associated with upregulation of CCL2 in the spinal cord, and is driven by recruitment of monocytes via a partially CCR2-dependent pathway. This study illustrates how regional differences in chemokine expression within a target organ shape the spatial pattern and composition of autoimmune infiltrates, leading to disparate clinical outcomes.

Topics: Animals; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Brain Stem; CD4-Positive T-Lymphocytes; Central Nervous System; Chemokines; Demyelinating Diseases; Encephalomyelitis, Autoimmune, Experimental; Flow Cytometry; Immunophenotyping; Inflammation; Interferon gamma Receptor; Interleukin-12; Interleukin-17; Interleukin-2 Receptor alpha Subunit; Lectins, C-Type; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Confocal; Monocytes; Myelin-Oligodendrocyte Glycoprotein; Neutrophils; Peptide Fragments; Receptors, CCR2; Receptors, Interferon; Receptors, Interleukin-8B

Single-chain fusion proteins comprised of GM-CSF and neuroantigen (NAg) are potent, NAg-specific inhibitors of experimental autoimmune encephalomyelitis (EAE). An important question was whether GMCSF-NAg tolerogenic vaccines retained inhibitory activity within inflammatory environments or were contingent upon steady-state conditions. GM-CSF fused to the myelin oligodendrocyte glycoprotein MOG35-55 peptide (GMCSF-MOG) reversed established paralytic disease in both passive and active models of EAE in C57BL/6 mice. The fusion protein also reversed EAE in CD4-deficient and B cell-deficient mice. Notably, GMCSF-MOG inhibited EAE when coinjected adjacent to the MOG35-55/CFA emulsion. GMCSF-MOG also retained dominant inhibitory activity when directly emulsified with MOG35-55 in the CFA emulsion in both C57BL/6 or B cell-deficient models of EAE. Likewise, when combined with proteolipid protein 139-151 in CFA, GM-CSF fused to proteolipid protein 139-151 peptide inhibited EAE in SJL mice. When deliberately emulsified in CFA with the NAg, GMCSF-NAg inhibited EAE even though NAg was present at >30-fold molar excess. In vitro studies revealed that the GM-CSF domain of GMCSF-MOG stimulated growth and differentiation of inflammatory dendritic cells (DC) and simultaneously targeted the MOG35-55 domain for enhanced presentation by these DC. These inflammatory DC presented MOG35-55 to MOG-specific T cells by an inhibitory mechanism that was mediated in part by IFN-γ signaling and NO production. In conclusion, GMCSF-NAg was tolerogenic in CFA-primed proinflammatory environments by a mechanism associated with targeted Ag presentation by inflammatory DC and an inhibitory IFN-γ/NO pathway. The inhibitory activity of GMCSF-NAg in CFA-primed lymphatics distinguishes GMCSF-NAg fusion proteins as a unique class of inflammation-dependent tolerogens that are mechanistically distinct from naked peptide or protein-based tolerogens.

Topics: Animals; Antigen Presentation; Autoantigens; Encephalomyelitis, Autoimmune, Experimental; Granulocyte-Macrophage Colony-Stimulating Factor; Immune Tolerance; Inflammation; Interferon-gamma; Mice; Myelin-Oligodendrocyte Glycoprotein; Nitric Oxide; Peptide Fragments; Recombinant Fusion Proteins

c-Rel plays important roles in many inflammatory diseases. Revealing the dynamic expression of c-Rel in disease processes in vivo is critical for understanding c-Rel functions and for developing anti-inflammatory drugs. In this paper, a transgenic mouse line, B6-Tg(c-Rel-luc)(Mlit), which incorporated the transgene firefly luciferase driven by a 14.5-kb fragment containing mouse c-Rel gene Rel promoter, was generated to monitor Rel expression in vivo. Luciferase expression could be tracked in living mice by the method of bioluminescence imaging in a variety of inflammatory processes, including LPS induced sepsis and EAE disease model. The luciferase expression in transgenic mice was comparable to the endogenous Rel expression and could be suppressed by administration of anti-inflammatory drug dexamethasone or aspirin. These results indicate that the B6-Tg(c-Rel-luc)(Mlit) mouse is a valuable animal model to study Rel expression in physiological and pathological processes, and the effects of various drug treatments in vivo.

Topics: Animals; Anti-Inflammatory Agents; Aspirin; Dexamethasone; Encephalomyelitis, Autoimmune, Experimental; Female; Gene Expression Regulation; Inflammation; Lipopolysaccharides; Luciferases, Firefly; Luminescent Measurements; Male; Mice; Mice, Transgenic; Molecular Imaging; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Proto-Oncogene Proteins c-rel; RNA, Messenger; Transcription, Genetic; Zymosan

Fractalkine, a chemokine anchored to neurons or peripheral endothelial cells, serves as an adhesion molecule or as a soluble chemoattractant. Fractalkine binds CX3CR1 on microglia and circulating monocytes, dendritic cells, and NK cells. The aim of this study is to determine the role of CX3CR1 in the trafficking and function of myeloid cells to the CNS during experimental autoimmune encephalomyelitis (EAE). Our results show that, in models of active EAE, Cx3cr1(-/-) mice exhibited more severe neurologic deficiencies. Bone marrow chimeric mice confirmed that CX3CR1 deficiency in bone marrow enhanced EAE severity. Notably, CX3CR1 deficiency was associated with an increased accumulation of CD115(+)Ly6C(-)CD11c(+) dendritic cells into EAE-affected brains that correlated with enhanced demyelination and neuronal damage. Furthermore, higher IFN-γ and IL-17 levels were detected in cerebellar and spinal cord tissues of CX3CR1-deficient mice. Analyses of peripheral responses during disease initiation revealed a higher frequency of IFN-γ- and IL-17-producing T cells in lymphoid tissues of CX3CR1-deficient as well as enhanced T cell proliferation induced by CX3CR1-deficient dendritic cells. In addition, adoptive transfer of myelin oligodendrocyte glycoprotein35-55-reactive wild-type T cells induced substantially more severe EAE in CX3CR1-deficient recipients when compared with wild-type recipients. Collectively, the data demonstrate that besides its role in chemoattraction, CX3CR1 is a key regulator of myeloid cell activation contributing to the establishment of adaptive immune responses.

Topics: Adaptive Immunity; Animals; Antigens, Ly; Autoimmunity; Bone Marrow Cells; CD11c Antigen; Cell Proliferation; Central Nervous System; Chimera; CX3C Chemokine Receptor 1; Demyelinating Diseases; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Interferon-gamma; Interleukin-1; Interleukin-17; Lymphocyte Activation; Lymphoid Tissue; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Myeloid Cells; Peptide Fragments; Receptor, Macrophage Colony-Stimulating Factor; Receptors, Chemokine; Receptors, Cytokine; Receptors, HIV; T-Lymphocytes

Cannabinoids, the Cannabis constituents, are known to possess anti-inflammatory properties but the mechanisms involved are not understood. Here we show that the main psychoactive cannabinoid, Δ-9-tetrahydrocannabinol (THC), and the main nonpsychoactive cannabinoid, cannabidiol (CBD), markedly reduce the Th17 phenotype which is known to be increased in inflammatory autoimmune pathologies such as Multiple Sclerosis. We found that reactivation by MOG35-55 of MOG35-55-specific encephalitogenic T cells (cells that induce Experimental Autoimmune Encephalitis when injected to mice) in the presence of spleen derived antigen presenting cells led to a large increase in IL-17 production and secretion. In addition, we found that the cannabinoids CBD and THC dose-dependently (at 0.1-5 μM) suppressed the production and secretion of this cytokine. Moreover, the mRNA and protein of IL-6, a key factor in Th17 induction, were also decreased. Pretreatment with CBD also resulted in increased levels of the anti-inflammatory cytokine IL-10. Interestingly, CBD and THC did not affect the levels of TNFα and IFNγ. The downregulation of IL-17 secretion by these cannabinoids does not seem to involve the CB1, CB2, PPARγ, 5-HT1A or TRPV1 receptors. In conclusion, the results show a unique cannabinoid modulation of the autoimmune cytokine milieu combining suppression of the pathogenic IL-17 and IL-6 cytokines along with boosting the expression of the anti-inflammatory cytokine IL-10.

Topics: Animals; Antigen-Presenting Cells; Cannabidiol; Cell Line; Coculture Techniques; Dronabinol; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Humans; Inflammation; Interferon-gamma; Interleukin-17; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Phenotype; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Th17 Cells; Tumor Necrosis Factor-alpha

The cell surface heparan sulfate proteoglycan, syndecan-1, has been reported to be a negative regulator of various inflammatory processes, but its precise mode of action is poorly defined. In this study, we use the murine model of the 35-55 peptide of myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE), a T lymphocyte-mediated inflammation where the steps in disease development and recovery are well characterized, to decipher how syndecan-1 impacts on the inflammatory reaction. Syndecan-1 knockout (Sdc-1(-/-)) mice show enhanced disease severity and impaired recovery. The use of bone marrow chimeric mice reveals that both an immune cell and a CNS-resident source of syndecan-1 contribute to this phenotype. Epithelial cells of the choroid plexus, where initial CCL20-induced leukocyte recruitment to the brain occurs, are identified as the predominant site of syndecan-1 expression. Syndecan-1 is lost from this site during the course of EAE by shedding into the cerebrospinal fluid, which correlates with loss of epithelial cell surface-bound CCL20 and is associated with the upregulation of IL-6 expression. In Sdc-1(-/-) mice, early leukocyte recruitment via the choroid plexus is enhanced, and IL-6 is elevated, which collectively results in higher numbers of the disease inducing Th17 cells in the CNS, thereby contributing to enhanced disease severity. Furthermore, Sdc-1(-/-) mice have intrinsically elevated plasma cell numbers and higher myelin oligodendrocyte glycoprotein-specific Ab levels during EAE, which we propose contributes to impaired recovery. Our data identify the choroid plexus epithelium as a novel source of IL-6 in EAE and demonstrate that its expression negatively correlates with syndecan-1 expression at this site.

Topics: Animals; Brain; Cell Differentiation; Cell Proliferation; Chemokine CCL20; Choroid Plexus; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Interleukin-6; Leukocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Plasma Cells; Signal Transduction; Syndecan-1; Th17 Cells; Up-Regulation

Optical neuritis (ON) is characterized by inflammation of the optic nerve, and is one of the first clinical signs of multiple sclerosis (MS). Experimental autoimmune encephalomyelitis (EAE) is the animal model used to study MS and ON. The present study evaluated the induction, development and progression of ON using an EAE model induced by 100 μg or 300 μg of MOG35-55. An EAE model was induced in C57BL/6 mice by tail base injection of 100 μg or 300 μg of MOG35-55 in complete Freund's adjuvant, supplemented with Mycobacterium tuberculosis. On the day of injection and 48 h later, animals received intraperitoneally 300 ng of pertussis toxin. On days 7, 10, 14, 21 and 58 the optic nerve was dissected for histological analysis, production of CCL5 and immunohistochemical detection of CD4 and CD8. The histological changes observed in the optic nerves consisted of inflammatory cell infiltrates showing varying degrees of ON in the two groups. The onset of ON in the 300 μg of MOG35-55 group was coincident with higher production of CCL5, on day 10 after induction. However, the 100 μg MOG35-55 group showed more intense inflammatory infiltrate on day 14 after induction, with higher amounts of CD4 and CD8, reaching an excessive demyelination process on days 21 and 58 after induction. The results suggest that two different concentrations of MOG35-55 lead to different forms of evolution of optic neuritis.

Topics: Animals; CD4 Antigens; CD4-Positive T-Lymphocytes; CD8 Antigens; CD8-Positive T-Lymphocytes; Chemokine CCL5; Disease Models, Animal; Dose-Response Relationship, Drug; Encephalomyelitis, Autoimmune, Experimental; Female; Humans; Inflammation; Inflammation Mediators; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Optic Neuritis; Peptide Fragments

The adhesion- and degranulation-promoting adaptor protein (ADAP), expressed in T cells, myeloid cells, and platelets, is known to regulate receptor-mediated inside-out signaling leading to integrin activation and adhesion. In this study, we demonstrate that, upon induction of active experimental autoimmune encephalomyelitis (EAE) by immunization with the myelin oligodendrocyte glycoprotein35-55 peptide, ADAP-deficient mice developed a significantly milder clinical course of EAE and showed markedly less inflammatory infiltrates in the CNS than wild-type mice. Moreover, ADAP-deficient recipients failed to induce EAE after adoptive transfer of myelin oligodendrocyte glycoprotein-specific TCR-transgenic T cells (2D2 T cells). In addition, ex vivo fully activated 2D2 T cells induced significantly less severe EAE in ADAP-deficient recipients. The ameliorated disease in the absence of ADAP was not due to expansion or deletion of a particular T cell subset but rather because of a strong reduction of all inflammatory leukocyte populations invading the CNS. Monitoring the adoptively transferred 2D2 T cells over time demonstrated that they accumulated within the lymph nodes of ADAP-deficient hosts. Importantly, transfer of complete wild-type bone marrow or even bone marrow of 2D2 TCR-transgenic mice was unable to reconstitute EAE in the ADAP-deficient animals, indicating that the milder EAE was dependent on (a) radio-resistant nonhematopoietic cell population(s). Two-photon microscopy of lymph node explants revealed that adoptively transferred lymphocytes accumulated at lymphatic vessels in the lymph nodes of ADAP-deficient mice. Thus, our data identify a T cell-independent mechanism of EAE modulation in ADAP-deficient mice.

Topics: Adaptor Proteins, Signal Transducing; Adoptive Transfer; Animals; Bone Marrow Transplantation; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Lymph Nodes; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Signal Transduction; T-Lymphocytes

T cells have an essential role in the induction of multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). Although for CD4(+) T cells it is well established that they contribute to the disease, less is known about the role of CD8(+) T cells. Our aim was to determine the individual contribution of CD4(+) and CD8(+) T cells in myelin oligodendrocyte glycoprotein (MOG)35-55-induced EAE. We investigated MOG35-55-activated CD8(+) T cells to clarify their potential to induce or attenuate EAE. We monitored the behavior of CD8(+) T cells and their interaction with CD4(+) T cells directly at the site of inflammation in the CNS using intravital imaging of the brainstem of EAE-affected living anesthetized mice. We found that mice without CD4(+) T cells did not develop relevant clinical signs of disease, although CD8(+) T cells were present in the CNS of these mice. These CD8(+) T cells displayed reduced motility compared with those in the presence of CD4(+) T cells. In mice that harbored CD4(+) and CD8(+) T cells, we saw a similar extent of clinical signs of EAE as in mice with only CD4(+) T cells. Furthermore, the dynamic motility and viability of CD4(+) T cells were not disturbed by CD8(+) T cells in the lesions of these mice. Therefore, we conclude that in MOG35-55-induced EAE, CD8(+) T cell accumulation in the CNS represents instead an epiphenomenon with no impact on clinical disease or on the effects of CD4(+) T cells, the latter being the true inducers of the disease.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Communication; Cell Movement; Central Nervous System; Encephalomyelitis, Autoimmune, Experimental; Inflammation; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments

Histamine is a biogenic amine that mediates multiple physiological processes, including immunomodulatory effects in allergic and inflammatory reactions, and also plays a key regulatory role in experimental allergic encephalomyelitis, the autoimmune model of multiple sclerosis. The pleiotropic effects of histamine are mediated by four G protein-coupled receptors, as follows: Hrh1/H(1)R, Hrh2/H(2)R, Hrh3/H(3)R, and Hrh4/H(4)R. H(4)R expression is primarily restricted to hematopoietic cells, and its role in autoimmune inflammatory demyelinating disease of the CNS has not been studied. In this study, we show that, compared with wild-type mice, animals with a disrupted Hrh4 (H(4)RKO) develop more severe myelin oligodendrocyte glycoprotein (MOG)(35\\x{2013}55)-induced experimental allergic encephalomyelitis. Mechanistically, we also show that H(4)R plays a role in determining the frequency of T regulatory (T(R)) cells in secondary lymphoid tissues, and regulates T(R) cell chemotaxis and suppressor activity. Moreover, the lack of H(4)R leads to an impairment of an anti-inflammatory response due to fewer T(R) cells in the CNS during the acute phase of the disease and an increase in the proportion of Th17 cells.

Topics: Animals; Blood-Brain Barrier; CD4 Lymphocyte Count; Cell Membrane Permeability; Cells, Cultured; Encephalomyelitis, Autoimmune, Experimental; Glycoproteins; Inflammation; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Myelin-Oligodendrocyte Glycoprotein; Neurons; Peptide Fragments; Receptors, G-Protein-Coupled; Receptors, Histamine; Receptors, Histamine H4; Severity of Illness Index; T-Lymphocytes, Regulatory

IL-9-producing Th9 cells have been associated with autoimmune diseases, such as experimental autoimmune encephalitis. However, the factors that negatively regulate Th9 cells during autoimmune inflammation are unclear. In this article, we show that IFN-γ inhibits Th9 differentiation both in vitro and in vivo. This suppressive activity was dependent on the transcription factor STAT-1. In addition to its direct inhibitory effect on Th9 differentiation, IFN-γ suppressed Th9 cells through the induction of IL-27 from dendritic cells. In vitro, treatment of naive CD4(+) T cells with IL-27 suppressed the development of Th9 cells, which was partially dependent on the transcription factors STAT-1 and T-bet. Moreover, IL-27 treatment completely abrogated the encephalitogenicity of Th9 cells in the experimental autoimmune encephalomyelitis model. Thus, our results identify a previously unknown mechanism by which IFN-γ limits Th9-mediated autoimmune inflammation through dendritic cell modulation of IL-27.

Topics: Animals; Cell Differentiation; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Gene Expression; Inflammation; Interferon-gamma; Interleukin-17; Interleukin-9; Interleukins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Signal Transduction; STAT1 Transcription Factor; T-Box Domain Proteins; T-Lymphocytes, Helper-Inducer

Glia maturation factor (GMF), a protein primarily localized in the central nervous system (CNS) was isolated, sequenced and cloned in our laboratory. We previously demonstrated that GMF mediates the experimental autoimmune encephalomyelitis (EAE)-induced production of pro-inflammatory cytokines and chemokines in the central nervous system of mice. In the present study we show that immunization with myelin oligodendrocyte glycoprotein peptide 35-55 (MOG35-55) caused an early onset (days 7-9 post immunization) and severe EAE with a mean peak score of 3.5 ± 0.5 in mice. Neutralization of GMF with four injections of anti-GMF antibody 5 to 11 days post immunization delayed the time of onset (days 12-14 post immunization) and significantly reduced the severity of EAE (mean peak score of 1.5 ± 0.4). Consistent with these clinical scores, histological examination of the CNS of these mice revealed profound differences between GMF-antibody treated mice and isotype matched control-antibody treated mice. Histological analysis of the spinal cord and brain showed severe inflammation and demyelination in the control antibody-treated mice whereas significantly reduced inflammation and demyelination was detected in GMF-antibody-treated mice at days 8, 16, and 24 post immunization. The decreased incidence and reduced severity of EAE in GMF-antibody-treated mice was consistent with the significantly reduced expressions of pro-inflammatory cytokines and chemokines. Our overall results demonstrate that neutralization of endogenous GMF with an affinity purified GMF antibody significantly decreased the inflammation, severity and progression of immunization induced active, passive and relapsing-remitting EAE. Treatment of mice with isotype-matched control antibody did not have any effect on EAE. Taken together, these results demonstrate the critical role of GMF in EAE, and GMF antibody as a potent anti-inflammatory therapeutic agent for effectively suppressing EAE in mouse models of major types of multiple sclerosis (MS).

Topics: Animals; Antibodies; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Glia Maturation Factor; Glycoproteins; Inflammation; Mice; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Neurons; Peptide Fragments; Pertussis Toxin; RNA, Messenger; Time Factors

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) characterized by inflammation, but also degenerative changes. Besides neurological deficits, the rate of affective disorders such as depression and anxiety is at least six fold increased. Many aspects of MS can be mimicked in the animal model of myelin oligodendrocyte glycoprotein experimental autoimmune encephalomyelitis (MOG-EAE). Here we investigate behavioral changes in C57BL/6 mice suffering from mild MOG-EAE. In the later phase of the disease, mice were subjected to behavioral tests including the light-dark-box (LD Box), the acoustic startle response (SR) with a pre-pulse inhibition protocol as well as the learned helplessness (LH) paradigm. Behavioral data were correlated with the motor performance in an open field and rotarod test (RR). In the RR and open field, there was no significant difference in the motor performance between controls and mice suffering from mild MOG-EAE. Yet EAE mice displayed an increased anxiety-like behavior with a 23% reduction of the time spent in the bright compartment of the LD Box as well as an increased SR. In the LH paradigm, mice suffering from MOG-EAE were twice as much prone to depressive-like behavior. These changes correlate with an increase of hippocampal tissue tumor necrosis factor alpha levels and neuronal loss in the hippocampus. Modulation of monoaminergic transmission by chronic application of the antidepressant amitriptyline resulted in a decreased startle reaction and increased hippocampal norepinephrine levels. These data imply that chronic inflammation in the CNS may impact on emotional responses in rodent models of anxiety.

Topics: Acoustic Stimulation; Amitriptyline; Analysis of Variance; Animals; Antidepressive Agents, Tricyclic; Anxiety; Central Nervous System; Chromatography, High Pressure Liquid; Cytokines; Dark Adaptation; Demyelinating Diseases; Depression; Disease Models, Animal; Dose-Response Relationship, Drug; Exploratory Behavior; Female; Gene Expression Regulation; Glycoproteins; Helplessness, Learned; Inflammation; Mice; Mice, Inbred C57BL; Motor Activity; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Pertussis Toxin; Phosphopyruvate Hydratase; Psychoacoustics; Reflex, Startle; Rotarod Performance Test; Stereotaxic Techniques; Time Factors

Alpha-1-antitrypsin (AAT) is the primary circulating serine protease inhibitor, and is known to exert potent anti-inflammatory effects and to inhibit the progression of several autoimmune diseases. In this study, transgenic mice that over-express surfactant-driven human (h)AAT on the C57BL/6 background were evaluated for resistance to MOG-35-55 peptide-induced experimental autoimmune encephalomyelitis (EAE), compared to WT C57BL/6 control mice. According to the results, sustained levels of circulating hAAT profoundly inhibited induction of clinical signs, inflammatory lesions and demyelination observed in WT mice with EAE, concomitant with enhanced levels of CD4+FoxP3+ Treg cells, reduced secretion of MOG peptide-induced pro-inflammatory cytokines, IL-17, IL-1β & IL-6, diminished expression of caspase-1 and enhanced expression of CCR6. These results implicate hAAT as a potent immunoregulatory agent worthy of further investigation as a potential therapy in human autoimmune diseases including multiple sclerosis.

Topics: alpha 1-Antitrypsin; Animals; Apoptosis; Caspases; Demyelinating Diseases; Encephalomyelitis, Autoimmune, Experimental; Forkhead Transcription Factors; Glycoproteins; Humans; Inflammation; Interleukin-17; Interleukin-1beta; Interleukin-6; Mice; Mice, Inbred C57BL; Mice, Transgenic; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, CCR6; Spinal Cord; Spleen; T-Lymphocytes, Regulatory

Axl, together with Tyro3 and Mer, constitute the TAM family of receptor tyrosine kinases. In the nervous system, Axl and its ligand Growth-arrest-specific protein 6 (Gas6) are expressed on multiple cell types. Axl functions in dampening the immune response, regulating cytokine secretion, clearing apoptotic cells and debris, and maintaining cell survival. Axl is upregulated in various disease states, such as in the cuprizone toxicity-induced model of demyelination and in multiple sclerosis (MS) lesions, suggesting that it plays a role in disease pathogenesis. To test for this, we studied the susceptibility of Axl-/- mice to experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis.. WT and Axl-/- mice were immunized with myelin oligodendrocyte glycoprotein (MOG)35-55 peptide emulsified in complete Freund's adjuvant and injected with pertussis toxin on day 0 and day 2. Mice were monitored daily for clinical signs of disease and analyzed for pathology during the acute phase of disease. Immunological responses were monitored by flow cytometry, cytokine analysis and proliferation assays.. Axl-/- mice had a significantly more severe acute phase of EAE than WT mice. Axl-/- mice had more spinal cord lesions with larger inflammatory cuffs, more demyelination, and more axonal damage than WT mice during EAE. Strikingly, lesions in Axl-/- mice had more intense Oil-Red-O staining indicative of inefficient clearance of myelin debris. Fewer activated microglia/macrophages (Iba1+) were found in and/or surrounding lesions in Axl-/- mice relative to WT mice. In contrast, no significant differences were noted in immune cell responses between naïve and sensitized animals.. These data show that Axl alleviates EAE disease progression and suggests that in EAE Axl functions in the recruitment of microglia/macrophages and in the clearance of debris following demyelination. In addition, these data provide further support that administration of the Axl ligand Gas6 could be therapeutic for immune-mediated demyelinating diseases.

Topics: Animals; Axl Receptor Tyrosine Kinase; Central Nervous System; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Glycoproteins; Inflammation; Macrophages; Mice; Mice, Knockout; Microglia; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases

Multiple sclerosis and its preclinical model, experimental autoimmune encephalomyelitis, are marked by perivascular inflammation and demyelination. Myeloid cells, derived from circulating progenitors, are a prominent component of the inflammatory infiltrate and are believed to directly contribute to demyelination and axonal damage. How the cytotoxic activity of these myeloid cells is regulated is poorly understood. We identify CMRF-35-like molecule-1 (CLM-1) as a negative regulator of autoimmune demyelination. CLM-1 is expressed on inflammatory myeloid cells present in demyelinating areas of the spinal cord after immunization of mice with MOG35-55 (myelin oligodendrocyte glycoprotein) peptide. Absence of CLM-1 resulted in significantly increased nitric oxide and proinflammatory cytokine production, along with increased demyelination and worsened clinical scores, whereas T cell responses in the periphery or in the spinal cord remained unaffected. This study thus identifies CLM-1 as a negative regulator of myeloid effector cells in autoimmune demyelination.

Topics: Animals; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Glycoproteins; Inflammation; Inflammation Mediators; Mice; Mice, Knockout; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Myeloid Cells; Nitric Oxide; Peptide Fragments; Receptors, Immunologic

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory immune response directed against myelin antigens of the central nervous system. In its murine model, EAE, Th17 cells play an important role in disease pathogenesis. These cells can induce blood-brain barrier disruption and CNS immune cells activation, due to the capacity to secrete high levels of IL-17 and IL-22 in an IL-6+TGF-β dependent manner. Thus, using the oral tolerance model, by which 200 μg of MOG 35-55 is given orally to C57BL/6 mice prior to immunization, we showed that the percentage of Th17 cells as well as IL-17 secretion is reduced both in the periphery and also in the CNS of orally tolerated animals. Altogether, our data corroborates with the pathogenic role of IL-17 and IFN-γ in EAE, as its reduction after oral tolerance, leads to an overall reduction of pro-inflammatory cytokines, such as IL-1α, IL-6, IL-9, IL-12p70 and the chemokines MIP-1β, RANTES, Eotaxin and KC in the CNS. It is noteworthy that this was associated to an increase in IL-10 levels. Thus, our data clearly show that disease suppression after oral tolerance induction, correlates with reduction in target organ inflammation, that may be caused by a reduced Th1/Th17 response.

Topics: Administration, Oral; Allergens; Amino Acid Sequence; Animals; Encephalomyelitis, Autoimmune, Experimental; Glycoproteins; Immune Tolerance; Immunosuppressive Agents; Inflammation; Interleukin-17; Lymphocyte Depletion; Male; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Myelin-Oligodendrocyte Glycoprotein; Nerve Tissue Proteins; Peptide Fragments; T-Lymphocytes, Helper-Inducer

Chronic inflammation can associate with autoreactive immune responses, including CD4(+) T cell responses to self-Ags. In this paper, we show that the adipocyte-derived proinflammatory hormone leptin can affect the survival and proliferation of autoreactive CD4(+) T cells in experimental autoimmune encephalomyelitis, an animal model of human multiple sclerosis. We found that myelin olygodendrocyte glycoprotein peptide 35-55 (MOG(35-55))-specific CD4(+) T cells from C57BL/6J wild-type mice could not transfer experimental autoimmune encephalomyelitis into leptin-deficient ob/ob mice. Such a finding was associated with a reduced proliferation of the transferred MOG(35-55)-reactive CD4(+) T cells, which had a reduced degradation of the cyclin-dependent kinase inhibitor p27(kip1) and ERK1/2 phosphorylation. The transferred cells displayed reduced Th1/Th17 responses and reduced delayed-type hypersensitivity. Moreover, MOG(35-55)-reactive CD4(+) T cells in ob/ob mice underwent apoptosis that associated with a downmodulation of Bcl-2. Similar results were observed in transgenic AND-TCR- mice carrying a TCR specific for the pigeon cytochrome c 88-104 peptide. These molecular events reveal a reduced activity of the nutrient/energy-sensing AKT/mammalian target of rapamycin pathway, which can be restored in vivo by exogenous leptin replacement. These results may help to explain a link between chronic inflammation and autoimmune T cell reactivity.

Topics: Animals; Apoptosis; Cell Proliferation; Chronic Disease; Cyclin-Dependent Kinase Inhibitor p27; Encephalomyelitis, Autoimmune, Experimental; Energy Metabolism; Female; Glycoproteins; Humans; Inflammation; Leptin; Mice; Mice, Obese; Mice, Transgenic; Mitogen-Activated Protein Kinase 3; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Species Specificity; Th1 Cells; Th17 Cells; TOR Serine-Threonine Kinases

The response of the immune system during injury of the central nervous system may play a role in protecting neurons. We have previously reported that immunization with MOG 35-55 prior to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced injury of the dopaminergic system promotes less dopamine depletion and less dopaminergic damage of neurons in mice. In this study, we evaluate the influence of MOG immunization on the inflammatory reaction that occurs at the place of injury. C57Bl male mice, 2 and 12 months old, received i.p. injections of MPTP (40 mg/kg) and some groups animals also received an additional injection with myelin oligodendrocyte glycoprotein (MOG) 35-55 in CFA 6 days before MPTP administration. MPTP caused a common inflammatory reaction characterized by microglial activation, infiltration of T cells into the substantia nigra and striatum and increased expression of mRNA encoding pro-inflammatory cytokines (IL-1 beta, TNFalpha, INF gamma) and trophic factors (TGFbeta, GDNF). MOG immunization prior to MPTP administration significantly diminished the microglial reaction and reduced the levels of infiltrating CD8+ lymphocytes. The number of CD4+ T cells remained at the same level as in the MPTP group. Expression of pro-inflammatory cytokines was diminished. The mRNA expression of GDNF was significantly higher in the MOG pretreated mice relative to the MPTP group, both in the 2 month old and 12 month old groups. Since MOG immunization prior to MPTP intoxication appears to prevent nigrostriatal injury, the observed decrease of inflammation and increase of GDNF mRNA expression in the injured areas might represent one of the mechanisms of observed neuroprotection.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Brain; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cytokines; Disease Models, Animal; Glycoproteins; Inflammation; Male; Mice; Mice, Inbred C57BL; MPTP Poisoning; Myelin-Oligodendrocyte Glycoprotein; Neurons; Peptide Fragments

The T-cell subsets, characterized by their cytokine production profiles and immune regulatory functions, depend on correct in vivo location to interact with accessory or target cells for effective immune responses. Differentiation of naive CD4(+) T cells into effectors is accompanied by sequentially regulated expression of the chemokine receptors responsible for cell recruitment to specific tissues. We studied CCR6 function in EAE, a CD4(+) T-cell-mediated CNS disease characterized by mononuclear infiltration and demyelination. CCR6(-/-) mice showed an altered time course of EAE development, with delayed onset, a higher clinical score, and more persistent symptoms than in controls. An imbalanced cytokine profile and reduced Foxp3(+) cell frequency characterized CNS tissues from CCR6(-/-) compared with CCR6(+/+) mice during the disease effector phase. Transfer of CCR6(+/+) Treg to CCR6(-/-) mice the day before EAE induction reduced the clinical score associated with an increased in infiltrating Foxp3(+) cells and recovery of the cytokine balance in CCR6(-/-) mouse CNS. Competitive assays between CCR6(+/+) and CCR6(-/-) Treg adoptively transferred to CCR6(-/-) mice showed impaired ability of CCR6(-/-) Treg to infiltrate CNS tissues in EAE-affected mice. Our data indicate a CCR6 requirement by CD4(+) Treg to downregulate the CNS inflammatory process and neurological signs associated with EAE.

Topics: Adoptive Transfer; Animals; Antibody Formation; Brain; Cell Count; Cell Movement; Central Nervous System; Chemokine CCL20; Cytokines; Encephalomyelitis, Autoimmune, Experimental; Forkhead Transcription Factors; Gene Expression; Glycoproteins; Inflammation; Lymph Nodes; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, CCR6; Remission, Spontaneous; Spinal Cord; T-Lymphocyte Subsets; T-Lymphocytes; T-Lymphocytes, Regulatory

Although macrophages (MPhi) are known as essential players in wound healing, their contribution to recovery from spinal cord injury (SCI) is a subject of debate. The difficulties in distinguishing between different MPhi subpopulations at the lesion site have further contributed to the controversy and led to the common view of MPhi as functionally homogenous. Given the massive accumulation in the injured spinal cord of activated resident microglia, which are the native immune occupants of the central nervous system (CNS), the recruitment of additional infiltrating monocytes from the peripheral blood seems puzzling. A key question that remains is whether the infiltrating monocyte-derived MPhi contribute to repair, or represent an unavoidable detrimental response. The hypothesis of the current study is that a specific population of infiltrating monocyte-derived MPhi is functionally distinct from the inflammatory resident microglia and is essential for recovery from SCI.. We inflicted SCI in adult mice, and tested the effect of infiltrating monocyte-derived MPhi on the recovery process. Adoptive transfer experiments and bone marrow chimeras were used to functionally distinguish between the resident microglia and the infiltrating monocyte-derived MPhi. We followed the infiltration of the monocyte-derived MPhi to the injured site and characterized their spatial distribution and phenotype. Increasing the naïve monocyte pool by either adoptive transfer or CNS-specific vaccination resulted in a higher number of spontaneously recruited cells and improved recovery. Selective ablation of infiltrating monocyte-derived MPhi following SCI while sparing the resident microglia, using either antibody-mediated depletion or conditional ablation by diphtheria toxin, impaired recovery. Reconstitution of the peripheral blood with monocytes resistant to ablation restored the lost motor functions. Importantly, the infiltrating monocyte-derived MPhi displayed a local anti-inflammatory beneficial role, which was critically dependent upon their expression of interleukin 10.. The results of this study attribute a novel anti-inflammatory role to a unique subset of infiltrating monocyte-derived MPhi in SCI recovery, which cannot be provided by the activated resident microglia. According to our results, limited recovery following SCI can be attributed in part to the inadequate, untimely, spontaneous recruitment of monocytes. This process is amenable to boosting either by active vaccination with a myelin-derived altered peptide ligand, which indicates involvement of adaptive immunity in monocyte recruitment, or by augmenting the naïve monocyte pool in the peripheral blood. Thus, our study sheds new light on the long-held debate regarding the contribution of MPhi to recovery from CNS injuries, and has potentially far-reaching therapeutic implications.

Topics: Adoptive Transfer; Animals; Glycoproteins; Inflammation; Interleukin-10; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Monocytes; Myelin-Oligodendrocyte Glycoprotein; Ovalbumin; Peptide Fragments; Spinal Cord; Spinal Cord Injuries

Haptoglobin (HP) is an acute phase protein synthesized by liver cells in response to IL-6. HP has been demonstrated to modulate the immune response and to have anti-inflammatory activities. To analyze HP's effect on autoimmune inflammation, we here studied the course of EAE induced by immunization of Hp knockout (Hp(-/-)) and syngeneic WT mice with myelin oligodendrocyte glycoprotein peptide (MOG(35-55)). Hp(-/-)mice suffered from a more severe disease that was associated with increased expression of IL-17A, IL-6, and IFN-gamma mRNA in the CNS and with a denser cellular infiltrate in the spinal cord. During the recovery phase, a significantly higher number of myeloid DC, CD8+ cells, IL-17+ CD4+ and IFN-gamma+ CD4+ cells persisted in the CNS of Hp(-/-) mice. Absence of HP affected the priming and differentiation of T cells after MOG(35-55) immunization, as levels of Th2 cytokines produced in response to MOG stimulation by Hp(-/-) T cells were reduced. These results suggest that HP plays a modulatory and protective role on autoimmune inflammation of the CNS.

Topics: Animals; Autoimmune Diseases; Brain; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Glycoproteins; Haptoglobins; Immunization; Immunoglobulin G; Inflammation; Interferon-gamma; Interleukin-10; Interleukin-17; Lymph Nodes; Mice; Mice, Inbred BALB C; Mice, Knockout; Myelin Proteins; Myelin-Associated Glycoprotein; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Reverse Transcriptase Polymerase Chain Reaction; Spinal Cord; Spleen; T-Lymphocytes; Th2 Cells; Transforming Growth Factor beta

We measured inflammatory and neural markers of disease from 7 days to one year after induction of experimental autoimmune encephalomyelitis (EAE) by immunization with myelin oligodendrocyte glycoprotein (MOG) peptide. Axon loss began before behavioral signs when T cell infiltration and microglial activation were very subtle. Remyelination was only detectable ultrastructurally. Axon numbers in the dorsal column plateau around day 30 p.i. while behavioral measures (EAE scores, rotarod, grip strength) partially recover. These results provide a starting point for testing potential neuroprotective treatments for multiple sclerosis (MS).

Topics: Animals; Behavior, Animal; Disease Progression; Encephalomyelitis, Autoimmune, Experimental; Female; Glycoproteins; Immunohistochemistry; Inflammation; Mice; Mice, Inbred C57BL; Microglia; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Recovery of Function; Spinal Cord; T-Lymphocytes; Time

Experimental allergic encephalomyelitis (EAE) is a T cell-mediated autoimmune disease model of multiple sclerosis. Signal transducer and activator of transcription 4 (Stat4) is a transcription factor activated by IL-12 and IL-23, two cytokines known to play important roles in the pathogenesis of EAE by inducing T cells to secrete IFN-gamma and IL-17, respectively. We and others have previously shown that therapeutic intervention or targeted disruption of Stat4 was effective in ameliorating EAE. Recently, a splice variant of Stat4 termed Stat4beta has been characterized that lacks 44 amino acids at the C terminus of the full-length Stat4alpha. In this study we examined whether T cells expressing either isoform could affect the pathogenesis of EAE. We found that transgenic mice expressing Stat4beta on a Stat4-deficient background develop an exacerbated EAE compared with wild-type mice following immunization with myelin oligodendrocyte glycoprotein peptide 35-55, while Stat4alpha transgenic mice have greatly attenuated disease. The differential development of EAE in transgenic mice correlates with increased IFN-gamma and IL-17 in Stat4beta-expressing cells in situ, contrasting increased IL-10 production by Stat4alpha-expressing cells. This study demonstrates that Stat4 isoforms differentially regulate inflammatory cytokines in association with distinct effects on the onset and severity of EAE.

Topics: Amino Acid Sequence; Animals; Encephalomyelitis, Autoimmune, Experimental; Gene Expression Regulation; Glycoproteins; Inflammation; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-17; Interleukin-23; Mice; Mice, Knockout; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Protein Isoforms; Sequence Deletion; STAT4 Transcription Factor; T-Lymphocytes

Autoimmune encephalomyelitis, a mouse model for multiple sclerosis, is characterized by the activation of immune cells, demyelination of axons in the CNS, and paralysis. We found that TGF-beta1 synthesis in glial cells and TGF-beta-induced signaling in the CNS were activated several days before the onset of paralysis in mice with autoimmune encephalomyelitis. While early production of TGF-beta1 was observed in glial cells TGF-beta signaling was activated in neurons and later in infiltrating T cells in inflammatory lesions. Systemic treatment with a pharmacological inhibitor of TGF-beta signaling ameliorated the paralytic disease and reduced the accumulation of pathogenic T cells and expression of IL-6 in the CNS. Priming of peripheral T cells was not altered, nor was the generation of TH17 cells, indicating that this effect was directed within the brain, yet affected the immune system. These results suggest that early production of TGF-beta1 in the CNS creates a permissive and dangerous environment for the initiation of autoimmune inflammation, providing a rare example of the brain modulating the immune system. Importantly, inhibition of TGF-beta signaling may have benefits in the treatment of the acute phase of autoimmune CNS inflammation.

Topics: Animals; Brain; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Genes, Reporter; Glycoproteins; Inflammation; Mice; Mice, Inbred C57BL; Mice, Transgenic; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Neuroglia; Neurons; Peptide Fragments; Signal Transduction; T-Lymphocyte Subsets; T-Lymphocytes, Helper-Inducer; Transforming Growth Factor beta1

Alpha-fetoprotein (AFP) is a 65-kDa oncofetal glycoprotein found in fetal and maternal fluids during pregnancy. Clinical remissions during pregnancy have been observed in several autoimmune diseases, such as multiple sclerosis (MS), and have been attributed to the presence of pregnancy-associated natural immune-reactive substances, including AFP which can exert immunomodulatory effects on immune cells. In this study, we tested the effect of recombinant human AFP (rhAFP) isolated from transgenic goats, which contain the genomic DNA for hAFP, on experimental autoimmune encephalomyelitis (EAE), the animal model used for the study of MS. RhAFP treatment markedly improved the clinical manifestations of EAE, preventing central nervous system (CNS) inflammation and axonal degeneration. RhAFP exerted a broad immunomodulating activity, influencing the various populations of immune cells. T cells from treated mice had significantly reduced activity towards the encephalitogenic peptide of myelin oligodendrocyte glycoprotein (MOG), exhibiting less proliferation and reduced Th1 cytokine secretion. Moreover, AFP affected the humoral response, causing an inhibition in MOG-specific antibody production. The expression of CD11b, MHC class II and the chemokine receptor CCR5 was also down-regulated. This is the first study demonstrating reduced inflammation and axonal damage exerted by recombinant AFP. In light of our findings, rhAFP may serve as a potential candidate for treatment of MS and other autoimmune diseases.

Topics: alpha-Fetoproteins; Analysis of Variance; Animals; Antibodies; Axons; CD11b Antigen; Cytokines; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Glycoproteins; Humans; Immunization; Immunoglobulin G; Inflammation; Mice; Mice, Inbred C57BL; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Radioimmunoassay; Recombinant Proteins; T-Lymphocytes; Thymidine; Time Factors

Peroxisome proliferator-activated receptor-gamma is a nuclear receptor transcription factor that regulates cell growth, differentiation and homeostasis. PPARgamma agonists have been used in the treatment of obesity, diabetes, cancer and inflammation. We and others have shown recently that PPARgamma agonists ameliorate experimental allergic encephalomyelitis (EAE), a Th1 cell-mediated autoimmune disease model of multiple sclerosis (MS). We have further shown that PPARgamma agonists inhibit EAE through blocking IL-12 signaling leading to Th1 differentiation and the PPARgamma-deficient heterozygous mice (PPARgamma(+/-)) develop an exacerbated EAE. In this study, we show that in vivo treatment (i.p.) with 100 mug PPARgamma antagonists, Bisphenol A diglycidyl ether (BADGE) or 2-Chloro-5-nitro-N-(4-pyridyl)benzamide (T0070907), on every other day from day 0 to 30, increased the severity and duration of EAE in C57BL/6 wild-type and PPARgamma(+/-) mice. The exacerbation of EAE by PPARgamma antagonists associates with an augmented neural antigen-induced T cell proliferation, IFNgamma production or Th1 differentiation. These results further suggest that PPARgamma is a critical physiological regulator of CNS inflammation and demyelination in EAE.

Topics: Animals; Benzamides; Benzhydryl Compounds; Cell Proliferation; Demyelinating Diseases; Dose-Response Relationship, Immunologic; Drug Administration Schedule; Drug Interactions; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Epoxy Compounds; Female; Glycoproteins; Inflammation; Interferon-gamma; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; PPAR gamma; Pyridines; Th1 Cells; Thymidine; Time Factors; Tritium

The scavenger receptor that binds phosphatidylserine and oxidized lipoprotein (SR-PSOX)/CXCL16 is a chemokine expressed on macrophages and dendritic cells, while its receptor expresses on T and NK T cells. We investigated the role of SR-PSOX/CXCL16 on acute and adoptive experimental autoimmune encephalomyelitis (EAE), which is Th1-polarized T cell-mediated autoimmune disease of the CNS. Administration of mAb against SR-PSOX/CXCL16 around the primary immunization decreased disease incidence of acute EAE with associated reduced infiltration of mononuclear cells into the CNS. Its administration was also shown to inhibit elevation of serum IFN-gamma level at primary immune response, as well as subsequent generation of Ag-specific T cells. In adoptive transfer EAE, treatment of recipient mice with anti-SR-PSOX/CXCL16 mAb also induced not only decreased clinical disease incidence, but also diminished traffic of mononuclear cells into the CNS. In addition, histopathological analyses showed that clinical development of EAE correlates well with expression of SR-PSOX/CXCL16 in the CNS. All the results show that SR-PSOX/CXCL16 plays important roles in EAE by supporting generation of Ag-specific T cells, as well as recruitment of inflammatory mononuclear cells into the CNS.

Topics: Acute Disease; Adoptive Transfer; Amino Acid Sequence; Animals; Antibodies, Monoclonal; Chemokine CXCL16; Chemokine CXCL6; Chemokines, CXC; Chemotaxis, Leukocyte; Demyelinating Diseases; Encephalomyelitis, Autoimmune, Experimental; Glycoproteins; Immunization; Inflammation; Lipoproteins, LDL; Membrane Proteins; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Phosphatidylserines; Receptors, Immunologic; Receptors, Scavenger; Spinal Cord; T-Lymphocyte Subsets

IL-12 is thought to be involved in the susceptibility to experimental autoimmune encephalomyelitis (EAE), a Th1 cell-mediated autoimmune disorder of the CNS. IL-12 signals through a heterodimeric receptor (IL-12Rbeta1/IL-12Rbeta2), whose beta2-chain is up-regulated on activated, autoreactive Th1 cells. Contrary to the expectation that the absence of IL-12Rbeta2 would protect from EAE, we found that IL-12Rbeta2-deficient mice developed earlier and more severe disease, with extensive demyelination and CNS inflammation. The inflammatory cells were mainly comprised of CD4(+) T cells, monocyte/macrophages, and dendritic cells. Compared to wild-type mice, IL-12Rbeta2-deficient mice exhibited significantly increased autoantigen-induced proliferative response and increased production of TNF-alpha, GM-CSF, IL-17, IL-18/IL-18Ralpha, and NO. In addition, we found significantly increased levels of IL-23p19 mRNA expression in spleen cells from immunized IL-12Rbeta2(-/-) mice compared with wild-type mice. These findings indicate that IL-12 responsiveness is not required in the pathogenesis of inflammatory demyelination in the CNS, and that, in the absence of IL-12Rbeta2, increased IL-23 and other inflammatory molecules may be responsible for increased severity of EAE.

Topics: Animals; Apoptosis; B-Lymphocyte Subsets; CD4-Positive T-Lymphocytes; Demyelinating Autoimmune Diseases, CNS; Encephalomyelitis, Autoimmune, Experimental; Epitopes, B-Lymphocyte; Epitopes, T-Lymphocyte; Genetic Predisposition to Disease; Glycoproteins; Inflammation; Interleukin-12; Interleukin-18; Interleukin-18 Receptor alpha Subunit; Interleukin-23; Interleukin-23 Subunit p19; Interleukins; Mice; Mice, Inbred C57BL; Mice, Knockout; Myelin-Oligodendrocyte Glycoprotein; Peptide Fragments; Receptors, Interleukin; Receptors, Interleukin-12; Receptors, Interleukin-18; RNA, Messenger; Severity of Illness Index; T-Lymphocyte Subsets; Up-Regulation