Antibodies from inflamed central nervous system tissue recognize myelin oligodendrocyte glycoprotein

Autoantibodies to myelin oligodendrocyte glycoprotein (MOG) can induce demyelination and oligodendrocyte loss in models of multiple sclerosis (MS). Whether anti-MOG Abs play a similar role in patients with MS or inflammatory CNS diseases by epitope spreading is unclear. We have therefore examined whether autoantibodies that bind properly folded MOG protein are present in the CNS parenchyma of MS patients. IgG was purified from CNS tissue of 14 postmortem cases of MS and 8 control cases, including cases of encephalitis. Binding was assessed using two independent assays, a fluorescence-based solid-phase assay and a solution-phase RIA. MOG autoantibodies were identified in IgG purified from CNS tissue by solid-phase immunoassay in 7 of 14 cases with MS and 1 case of subacute sclerosing panencephalitis, but not in IgG from noninflamed control tissue. This finding was confirmed with a solution-phase RIA, which measures higher affinity autoantibodies. These data demonstrate that autoantibodies recognizing MOG are present in substantially higher concentrations in the CNS parenchyma compared with cerebrospinal fluid and serum in subjects with MS, indicating that local production/accumulation is an important aspect of autoantibody-mediated pathology in demyelinating CNS diseases. Moreover, chronic inflammatory CNS disease may induce autoantibodies by virtue of epitope spreading.

CD8+-dependent CNS demyelination following ocular infection of mice with a recombinant HSV-1 expressing murine IL-2

Demyelinating diseases comprise a spectrum of immunopathologic syndromes in which myelin, the fatty covering of nerve cell fibers in the brain and spinal cord, is destroyed. In this study, we have shown for the first time that ocular infection of BALB/c mice with a recombinant herpes simplex virus type 1 (HSV-1) expressing IL-2 (HSV-IL-2) results in CNS demyelination as determined by light microscopy and EM. The demyelinated lesions involve periventricular white matter, brain stem, and spinal cord white matter. Demyelination was detected in the CNS of infected mice up to 75 days (the longest time point tested) post HSV-IL-2 infection. In contrast, mice infected with HSV-IFN-gamma or HSV-IL-4, which are identical to HSV-IL-2 but express IFN-gamma or IL-4 instead of IL-2, did not exhibit demyelination. Control mice infected with wild-type HSV-1 or parental virus also remained free of these symptoms. During early times (days 3-7), post-infection with HSV-IL-2 virus, a T(H)1 + T(H)2 pattern of cytokines was produced by lymphocytes of infected mice while mice infected with HSV-IFN-gamma or control viruses produced a T(H)1 pattern of cytokine. By day 21 post-infection, all infected groups exhibited a T(H)1 pattern of response. Immunohistochemistry and FACS analyses of infiltrates in the brains and spinal cords of HSV-IL-2-infected mice showed elevations in CD4+ and CD8+ T cells and macrophages. However, T cell depletion studies suggest that only central memory CD8+ T cells are directly involved in the demyelination process, with macrophages being involved through a bystander effect.

Motor neuron pathology in experimental autoimmune encephalomyelitis: studies in THY1-YFP transgenic mice

Using adult male C57BL/6 mice that express a yellow fluorescent protein transgene in their motor neurons, we induced experimental autoimmune encephalomyelitis (EAE) by immunization with myelin oligodendrocyte glycoprotein peptide 35-55 (MOG peptide) in complete Freund's adjuvant (CFA). Control mice of the same transgenic strain received CFA without MOG peptide. Early in the course of their illness, the EAE mice showed lumbosacral spinal cord inflammation, demyelination and axonal fragmentation. By 14 weeks post-MOG peptide, these abnormalities were much less prominent, but the mice remained weak and, as in patients with progressive multiple sclerosis, spinal cord atrophy had developed. There was no significant loss of lumbar spinal cord motor neurons in the MOG peptide-EAE mice. However, early in the course of the illness, motor neuron dendrites were disrupted and motor neuron expression of hypophosphorylated neurofilament-H (hypoP-NF-H) immunoreactivity was diminished. By 14 weeks post-MOG peptide, hypoP-NF-H expression had returned to normal, but motor neuron dendritic abnormalities persisted and motor neuron perikaryal atrophy had appeared. We hypothesize that these motor neuron abnormalities contribute to weakness in this form of EAE and speculate that similar motor neuron abnormalities are present in patients with progressive multiple sclerosis.

Hepatitis B vaccination and central nervous system demyelination: an immunological approach

Demyelination events or multiple sclerosis following hepatitis B virus (HBV) vaccination have been reported. We therefore compared the T-cell response to HBsAg in patients with CNS demyelination following HBV vaccination and in HBV-vaccinated healthy individuals. Our data showed no differences in terms of T-cell proliferation or cytokine production between these groups and may help to allay concerns that HBV vaccination might trigger a deleterious immune response.

Selective and Antigen-Dependent Effects of Myelin Degeneration on Central Nervous System Inflammation

Damage to myelin sheath or oligodendrocytes may precede or even provoke inflammation of the central nervous system (CNS), but the extent to which these degenerative changes affect inflammation remains largely undefined. To study these processes in more detail, we used CNS antigen-specific T cells in the presence or absence of anti-myelin antibodies to induce experimental autoimmune encephalomyelitis (EAE) in transgenic Lewis rats with low-grade subclinical myelin degeneration and associated microglia cell activation, and in wild-type Lewis rats with an intact CNS. We found that myelin degeneration affects the localization of inflammatory lesions, the numbers of T cells recruited to these lesions, and the severity of the resulting clinical disease. In addition, myelin degeneration and associated microglia cell activation jointly enhance the susceptibility of the CNS to the action of anti-myelin antibodies. Our data show that even subtle alterations of myelin and oligodendrocytes may massively amplify the extent of demyelination and tissue damage, involving different immune effector mechanisms. A similar causal relationship might also operate in human patients with multiple sclerosis, where T cell-mediated inflammation and antibody-mediated demyelination have been documented, and where genetic factors might determine the susceptibility of the target tissue for immune-mediated injury.

Thyroid hormone administration enhances remyelination in chronic demyelinating inflammatory disease

Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degeneration, which follow remyelination failure. Due to the presence of numerous oligodendrocyte precursors inside demyelination plaques, one reason for demyelination failure could be the inability of oligodendrocyte precursor cells to turn into myelinating oligodendrocytes. In this study, we show that thyroid hormone enhances and accelerates remyelination in an experimental model of chronic demyelination, i.e., experimental allergic encephalomyelitis in congenic female Dark Agouti rats immunized with complete guinea pig spinal cord. Thyroid hormone, when administered during the acute phase of the disease, increases expression of platelet-derived growth factor alpha receptor, restores normal levels of myelin basic protein mRNA and protein, and allows an early and morphologically competent reassembly of myelin sheaths. Moreover, thyroid hormone exerts a neuroprotective effect with respect to axonal pathology.

Microglia and macrophage activation and the regulation of complement-receptor-3 (CR3/MAC-1)-mediated myelin phagocytosis in injury and disease

Microglia and macrophages play critical roles in the response of the central and peripheral nervous systems (CNS and PNS, respectively) to injury and disease, one of which is the removal of degenerated myelin by phagocytosis. Myelin removal is efficient during Wallerian degeneration, which follows injury to PNS axons, and in CNS autoimmune demyelinating diseases (e.g., multiple sclerosis) but is inefficient after injury to CNS axons. We suggest that inefficient myelin removal results from deficient microglia activation, reflected by the failure to up-regulate Galectin-3/MAC-2 expression, which marks a state of activation correlated with efficient myelin phagocytosis. Surprisingly, whether or not executing myelin phagocytosis, CNS microglia express the alphaM/beta2 integrin complement receptor-3 (CR3/MAC-1), which has the potential of mediating efficient myelin phagocytosis. We hypothesize that CR3/MAC-1 might be present in distinct inactive and active states that determine, respectively, efficient and inefficient CR3/MAC-1-mediated myelin phagocytosis. We present evidence that CR3/MAC-1-mediated myelin phagocytosis is regulated in microglia and macrophages. First, CR3/MAC-1- mediated myelin phagocytosis has complement-dependent and -independent components. Second, an active complement system augments CR3/MAC-1-mediated myelin phagocytosis. Third, anti-alphaM monoclonal antibodies (MAbs) inhibit and anti-beta2 MAbs augment CR3/MAC-1-mediated myelin phagocytosis in the presence and absence of an active complement system. Fourth, an active complement system modulates MAb-induced regulation of CR3/MAC-1-mediated myelin phagocytosis. Overall, MAb-induced phagocytosis regulation might range three- to sevenfold from inefficient to efficient. We suggest that one of the mechanisms underlying MAb-induced phagocytosis regulation is the induction/stabilization of inactive and active conformational changes. Monoclonal antibody-induced phagocytosis regulation must reveal a mechanism by which native extracellular molecules bind to and regulate CR3/MAC-1-mediated myelin phagocytosis in microglia and macrophages.

MRI prognostic factors for relapse after acute CNS inflammatory demyelination in childhood

The prognostic factors for relapse of the initial MRI findings after a first episode of acute CNS inflammatory demyelination are unclear in children. In this study we aimed to identify initial MRI factors that are predictive of a second attack and disability after a first episode of acute CNS inflammatory demyelination in childhood. A cohort of 116 children who had a first episode of acute CNS inflammatory demyelination between 1990 and 2002 was studied using survival analysis methods. The initial MRI data were reviewed in a systematic, standardized, double-blind manner. The average follow-up was 4.9 +/- 3 years. Multivariate analysis showed that the rate of second attack was higher in patients with corpus callosum long axis perpendicular lesions (34 out of 116 patients, 30%) on the initial MRI [hazard ratio (HR) 2.89; 95% confidence interval (CI) 1.65-5.06] and/or with the sole presence of well-defined lesions (46 out of 116 patients, 40%) (HR 1.71; 95% CI 1.29-2.27). Both criteria were more specific predictors (100%) of relapse, demonstrating conversion to multiple sclerosis, than the three Barkhof criteria (63%), but were less sensitive (21% compared with 52%). None of the MRI criteria was predictive of severe disability. Using initial MRI and survival analysis methods, we identified two specific predictors of relapse and conversion to multiple sclerosis after a first episode of acute CNS inflammatory demyelination in childhood. Their low sensitivity, however, shows that this prediction remains difficult.

Recurrent paraplegia after remyelination of the spinal cord

We have conducted a long-term study of spinal cord morphology and motor function recovery in rats that have undergone lumbar spinal demyelination induced by the B-fragment of cholera toxin (CTB)-saporin. We found that, after the initial demyelination and paraplegia, motor function recovered and was stable for up to 9 months, after which there occurred a slow deterioration of motor function accompanied by loss of motoneurons and loss of spinal white matter. A striking morphological feature was the appearance of large spheroids of calcium in the ventral and dorsal horns and occasionally in the white matter. Motor performance deterioration occurred earlier and was more severe in rats that had been exercised on a treadmill, but the same morphological changes occurred in both exercise- and nonexercise-treated animals. Rats given treadmill exercise starting 3 weeks after toxin injection had a mean motor deficit score of 3.0 (i.e., paraplegia) at perfusion, whereas the nontreadmill-treated rats had a mean score of 1.8 (SD 0.38; n = 6; P <.05). These findings suggest that, in addition to the acute effects of the toxin-induced demyelination from which there is recovery of motor function, there are chronic irreversible effects of the toxin, or the initial demyelination, that cause a slow progressive degeneration of the spinal cord. This model might therefore be useful in studying the long-term effects of spinal insult of the type associated with conditions such as postpolio syndrome.

In vivo magnetic resonance imaging of immune cells in the central nervous system with superparamagnetic antibodies

We developed a novel MRI technique to image immune cell location and homing in vivo to the central nervous system (CNS). Superparamagnetic antibodies specific for cell surface markers allowed imaging of CD4+ T cells, CD8+ T cells, and Mac1+ cells in the CNS of mice infected with Theiler's murine encephalomyelitis virus (TMEV) and in mice with experimental autoimmune encephalomyelitis (EAE). Superparamagnetic antibodies have excellent T2, T2*, and good T1 relaxation properties, which makes them ideal MRI contrast materials. Immunohistochemistry of corresponding sections confirmed the specificity of the technique to detect immune cell types in the CNS. This powerful technique has potential to image any cell with unique surface antigens. Because superparamagnetic antibodies similar to those used in the study are approved for human use, the in vivo MRI technique we have described could be developed for human use.

Caspase-mediated oligodendrocyte cell death in the pathogenesis of autoimmune demyelination

Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory diseases of the central nervous system (CNS) characterized by localized areas of demyelination. MS is believed to be an autoimmune disorder mediated by activated immune cells such as T- and B-lymphocytes and macrophages/microglia. Lymphocytes are primed in the peripheral tissues by antigens, and clonally expanded cells infiltrate the CNS. They produce large amounts of inflammatory and cytokines that lead to demyelination and axonal degeneration. Although several studies have shown that oligodendrocytes (OLGs), the myelin-forming glial cells in the CNS, are sensitive to cell death stimuli, such as cytotoxic cytokines, anti-myelin antibodies, nitric oxide, and oxidative stress, in vitro, the mechanisms underlying injury to the OLGs in MS/EAE remain unclear. Transgenic mice that express the anti-apoptotic protein specifically in OLGs and caspase-11-deficient mice are significantly resistant to EAE induction. Histopathological analyses show that the number of caspase-activated OLGs and dead OLGs are reduced in the CNS of these mice. The numbers of infiltrating immune cells and the amounts of cytokines are also markedly reduced in EAE lesions. Therefore, caspase-mediated OLG death leads to the exacerbation of demyelination and the deterioration of neurological manifestations by inducing local inflammatory events.

Central nervous system involvement in autoimmune polyglandular syndrome

We present a 33 year-old man, admitted because of transient deterioration of visual acuity. Magnetic resonance imaging showed diffuse central nervous system (CNS) demyelination, which largely resolved spontaneously within 4 months. The patient fulfilled the diagnostic criteria of APS type III, having autoimmune thyroiditis and alopecia universalis. In this patient, autoimmune activation against CNS antigens is thought to be the cause of reversible CNS demyelination.

Induction of experimental autoimmune encephalomyelitis in IL-12 receptor-beta 2-deficient mice: IL-12 responsiveness is not required in the pathogenesis of inflammatory demyelination in the central nervous system

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.

IL-12p35-deficient mice are susceptible to experimental autoimmune encephalomyelitis: evidence for redundancy in the IL-12 system in the induction of central nervous system autoimmune demyelination

Experimental autoimmune encephalomyelitis (EAE) serves as a model for multiple sclerosis and is considered a CD4(+), Th1 cell-mediated autoimmune disease. IL-12 is a heterodimeric cytokine, composed of a p40 and a p35 subunit, which is thought to play an important role in the development of Th1 cells and can exacerbate EAE. We induced EAE with myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 (MOG(35-55)) in C57BL/6 mice and found that while IL-12p40-deficient (-/-) mice are resistant to EAE, IL-12p35(-/-) mice are susceptible. Typical spinal cord mononuclear cell infiltration and demyelination were observed in wild-type and IL-12p35(-/-) mice, whereas IL-12p40(-/-) mice had normal spinal cords. A Th1-type response to MOG(35-55) was observed in the draining lymph node and the spleen of wild-type mice. A weaker MOG(35-55)-specific Th1 response was observed in IL-12p35(-/-) mice, with lower production of IFN-gamma. By contrast, a Th2-type response to MOG(35-55) correlated with disease resistance in IL-12p40(-/-) mice. Production of TNF-alpha by microglia, CNS-infiltrating macrophages, and CD4(+) T cells was detected in wild-type and IL-12p35(-/-), but not in IL-12p40(-/-), mice. In addition, NO production was higher in IL-12p35(-/-) and wild-type mice than in IL-12p40(-/-) mice. These data demonstrate a redundancy of the IL-12 system in the induction of EAE and suggest that p40-related heterodimers, such as the recently cloned IL-23 (p40p19), may play an important role in disease pathogenesis.

Evidence for the role of demyelination, HLA-DR alleles, and cytokines in the pathogenesis of parvovirus B19 meningoencephalitis and its sequelae

OBJECTIVE

To review the clinical and pathological features of parvovirus B19 meningoencephalitis and its sequelae in 12 previously published cases, and to perform additional tests to determine the pathogenesis of the disease.

METHODS

Cases were reviewed and available serum and cerebrospinal fluid (CSF) tested for antiganglioside antibodies and a range of cytokines. In situ hybridisation for parvovirus B19 DNA was performed on postmortem brain tissue in two cases. HLA-DRB1 typing was undertaken on genomic DNA extracted from peripheral blood leucocytes.

RESULTS

Cerebellar involvement was suggested either clinically or pathologically in four cases. In the two cases with postmortem histology, there was marked atrophy of the molecular and granular layers of the cerebellum with focal loss of Purkinje cells. Brain scanning by MRI or CT was done in six cases during the acute phase. Three were abnormal with evidence of demyelination. Three had markedly enlarged ventricles, in two of which there was high signal intensity from the white matter on both T1 and T2 weighted images. The three cases with abnormal brain scans had long term neurological sequelae (mental retardation, personality change, altered affect). In situ hybridisation on available postmortem brain tissue was negative in the two cases tested. All cases in which HLA-DR alleles were determined carried at least one of the following alleles: HLA-DRB1*01, *04, *07, *09, *15, *16. Available serum and CSF was tested for antiganglioside antibodies (all negative) and for a panel of cytokines, which had a similar profile in both serum (n = 5) and CSF (n = 1) during the acute phase. Cytokines that were consistently detectable were IL-6 (mean 726.20 pg/ml), TNFalpha (50.64 pg/ml), IFNgamma (39.64 pg/ml), GM-CSF (216.12 pg/ml), and MCP-1 (154.43 pg/ml); IL-1beta, IL-5, and IL-13 were undetectable.

CONCLUSIONS

HLA-DR associations, an increased cytokine response, and benefit from immunomodulatory treatment (in one case) support a role for the immune response in the pathogenesis of parvovirus B19 meningoencephalitis.

Cutting edge: CD4+CD25+ regulatory T cells suppress antigen-specific autoreactive immune responses and central nervous system inflammation during active experimental autoimmune encephalomyelitis

Autoreactive CD4(+) T cells exist in normal individuals and retain the capacity to initiate autoimmune disease. The current study investigates the role of CD4(+)CD25(+) T-regulatory (T(R)) cells during autoimmune disease using the CD4(+) T cell-dependent myelin oligodendrocyte glycoprotein (MOG)-specific experimental autoimmune encephalomyelitis model of multiple sclerosis. In vitro, T(R) cells effectively inhibited both the proliferation of and cytokine production by MOG(35-55)-specific Th1 cells. In vivo, adoptive transfer of T(R) cells conferred significant protection from clinical experimental autoimmune encephalomyelitis which was associated with normal activation of autoreactive Th1 cells, but an increased frequency of MOG(35-55)-specific Th2 cells and decreased CNS infiltration. Lastly, transferred T(R) cells displayed an enhanced ability to traffic to the peripheral lymph nodes and expressed increased levels of the adhesion molecules ICAM-1 and P-selectin that may promote functional interactions with target T cells. Collectively, these findings suggest that T(R) cells contribute notably to the endogenous mechanisms that regulate actively induced autoimmune disease.

[Paraneoplastic cerebellar degeneration associated with ovarian cancer: anti-Yo immunoreactivity in autoptic cerebellum and ovarian carcinoma]

Paraneoplastic cerebellar degeneration is a rare disorder caused likely by autoimmune mechanisms in malignant oncologic diseases, and the most common tumors are ovarian, breast, lung cancer, and m. Hodgkin. An immune reaction is supposed to be directed against identical antigens of cerebellum and tumor, and paraneoplastic antibodies called anti-Yo, anti-Hu, anti-Ri, or anti-Tr are often detected in blood and cerebrospinal fluid. The course of paraneoplastic cerebellar degeneration as a complication of ovarian cancer is described. The relationship between the malignancy and pathologic changes in cerebellum was confirmed by positive immunohistochemical and immunofluorescence reaction between a patient's anti-Yo-positive serum and her own Purkinje's and ovarian cancer cells.

Direct evidence that a human antibody derived from patient serum can promote myelin repair in a mouse model of chronic-progressive demyelinating disease

Certain human sera from patients with monoclonal gammopathies contain factors that induce myelin repair in animals with demyelinating disease. We hypothesize that antibodies functionally distinguish the serum of one patient from another. However, pooled normal polyclonal human IgM antibodies also induce remyelination. Definitive proof that specific antibodies are the biologically active components of serum is missing because unquestionably pure preparations of antibody molecules cannot be generated by fractionation. To demonstrate definitively that antibody is the biologically active component of patient serum, recombinant antibody was generated for evaluation in bioassays. The induction of remyelination in vivo requires milligram quantities of antibody. Consequently, an expression system was engineered to express high-titer, recombinant human IgM antibodies in vitro. A resulting recombinant antibody (rHIgM22) was evaluated for its ability to induce remyelination in the Theiler's virus mouse model of chronic-progressive demyelinating disease. We demonstrate that a single recombinant monoclonal antibody recapitulates the key characteristics of patient serum, including binding specificity, the induction of calcium signals in oligodendrocytes in vitro, and the induction of myelin repair within demyelinated plaques in vivo. The rHIgM22 antibody provides a new venue for the analysis of mechanisms governing remyelination and may prove useful in the treatment of demyelinating diseases.

Osmotic demyelination syndrome after correction of chronic hyponatremia with normal saline

Rapid correction of severe chronic hyponatremia with hypertonic saline has been known to cause osmotic demyelination syndrome (ODS). Less recognized are the dangers of rapid correction with normal saline. A 60-year-old woman on thiazide diuretics for hypertension presented with profound hyponatremia (94 mmol/L) and hypokalemia (1.9 mmol/L) associated with volume depletion. Normal saline (2 L/day) and (KCl 40 mmol/day) were given for 5 days. Serum Na+ concentration rose to 106 mmol/L within 18 hours. With improvement of her hyponatremia, she became more alert although the hypokalemia persisted. However, she developed progressive obtundation, quadriplegia, and respiratory failure 6 days later. Magnetic resonance imaging of the brain clearly showed typical features of pontine and extrapontine myelinolysis. We suggest that the aggressive KCl supplement would have been the first-line therapy for this patient presenting with chronic hyponatremia and hypokalemia associated with volume depletion.

Absence of macrophage-inflammatory protein-1alpha delays central nervous system demyelination in the presence of an intact blood-brain barrier

Chemokines are small chemotactic cytokines that modulate leukocyte recruitment and activation during inflammation. Here, we describe the role of macrophage inflammatory protein-1alpha (MIP-1alpha) during cuprizone intoxication, a model where demyelination of the CNS features a large accumulation of microglia/macrophage without T cell involvement or blood-brain barrier disruption. RNase protection assays showed that mRNA for numerous chemokines were up-regulated during cuprizone treatment in wild-type, C57BL/6 mice. RANTES, inflammatory protein-10, and monocyte chemoattractant protein-1 showed greatest expression with initiation of insult at 1-2 wk of treatment, whereas MIP-1alpha and beta increased later at 4-5 wk, coincident with peak demyelination and cellular accumulation. The function of MIP-1alpha during demyelination was tested in vivo by exposing MIP-1alpha knockout mice (MIP-1alpha(-/-)) to cuprizone and comparing pathology to wild-type mice. Demyelination at 3.5 wk of treatment was significantly decreased in MIP-1alpha(-/-) mice ( approximately 36% reduction), a result confirmed by morphology at the electron microscopic level. The delay in demyelination was correlated to apparent decreases in microglia/macrophage and astrocyte accumulation and in TNF-alpha protein levels. It was possible that larger effects of the MIP-1alpha deficiency were being masked by other redundant chemokines. Indeed, RNase protection assays revealed increased expression of several chemokine transcripts in both untreated and cuprizone-treated MIP-1alpha(-/-) mice. Nonetheless, despite this possible compensation, our studies show the importance of MIP-1alpha in demyelination in the CNS and highlight its effect, particularly on cellular recruitment and cytokine regulation.

[Diagnostic criteria of borderline forms of multiple sclerosis]

Border forms of multiple sclerosis (MS) can be separated in two groups: either they are variants of MS or they are distinct from MS but they share several characteristics with MS thus representing for some of them a continuum with MS. All these entities are central nervous system demyelinating diseases. Here we describe, for the first group, MS in childhood, MS in elderly subjects, Balò's concentric sclerosis, Schilder's myelinoclastic diffuse sclerosis and MS simulating a mass lesion, and for the second group, acute disseminated encephalomyelitis and Devic's neuromyelitis optica.

MIP-1alpha, MCP-1, GM-CSF, and TNF-alpha control the immune cell response that mediates rapid phagocytosis of myelin from the adult mouse spinal cord

The slow immune response in the adult mammalian CNS results in slow myelin phagocytosis along degenerating white matter after injury. This has important consequences for axon regeneration because of the presence of axon growth inhibitors in myelin. In addition, abnormal immune cell responses in the CNS lead to demyelinating disease. Lysophosphatidylcholine (LPC) can induce an inflammatory response in the CNS, producing rapid demyelination without much damage to adjacent cells. In this study, we searched for the molecular switches that turn on this immune cell response. Using reverse transcription PCR analysis, we show that mRNA expression of macrophage inflammatory protein-1alpha (MIP-1alpha), macrophage chemotactic protein-1 (MCP-1), granulocyte macrophage-colony stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha) in the spinal cord is rapidly and transiently upregulated after intraspinal injection of LPC. Neutralizing these signaling molecules with function-blocking antibodies suppresses recruitment of T-cells, neutrophils, and monocytes into the spinal cord, as well as significantly reduces the number of phagocytic macrophages and the demyelination induced by LPC. These findings will have important implications for CNS regeneration and demyelinating disease.