Native Myelin Oligodendrocyte Glycoprotein Research Articles

Do Myelin Oligodendrocyte Glycoprotein Antibodies Represent a Distinct Syndrome?

Do Myelin Oligodendrocyte Glycoprotein Antibodies Represent a Distinct Syndrome?

Functional characterization of reappearing B cells after anti-CD20 treatment of CNS autoimmune disease

The anti-CD20 antibody ocrelizumab, approved for treatment of multiple sclerosis, leads to rapid elimination of B cells from the blood. The extent of B cell depletion and kinetics of their recovery in different immune compartments is largely unknown. Here, we studied how anti-CD20 treatment influences B cells in bone marrow, blood, lymph nodes, and spleen in models of experimental autoimmune encephalomyelitis (EAE). Anti-CD20 reduced mature B cells in all compartments examined, although a subpopulation of antigen-experienced B cells persisted in splenic follicles. Upon treatment cessation, CD20+ B cells simultaneously repopulated in bone marrow and spleen before their reappearance in blood. In EAE induced by native myelin oligodendrocyte glycoprotein (MOG), a model in which B cells are activated, B cell recovery was characterized by expansion of mature, differentiated cells containing a high frequency of myelin-reactive B cells with restricted B cell receptor gene diversity. Those B cells served as efficient antigen-presenting cells (APCs) for activation of myelin-specific T cells. In MOG peptide-induced EAE, a purely T cell-mediated model that does not require B cells, in contrast, reconstituting B cells exhibited a naive phenotype without efficient APC capacity. Our results demonstrate that distinct subpopulations of B cells differ in their sensitivity to anti-CD20 treatment and suggest that differentiated B cells persisting in secondary lymphoid organs contribute to the recovering B cell pool.

Simple and Efficient Production and Purification of Mouse Myelin Oligodendrocyte Glycoprotein for Experimental Autoimmune Encephalomyelitis Studies.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), thought to occur as a result of autoimmune responses targeting myelin. Experimental autoimmune encephalomyelitis (EAE) is the most common animal model of CNS autoimmune disease, and is typically induced via immunization with short peptides representing immunodominant CD4+ T cell epitopes of myelin proteins. However, B cells recognize unprocessed protein directly, and immunization with short peptide does not activate B cells that recognize the native protein. As recent clinical trials of B cell-depleting therapies in MS have suggested a role for B cells in driving disease in humans, there is an urgent need for animal models that incorporate B cell-recognition of autoantigen. To this end, we have generated a new fusion protein containing the extracellular domain of the mouse version of myelin oligodendrocyte glycoprotein (MOG) as well as N-terminal fusions of a His-tag for purification purposes and the thioredoxin protein to improve solubility (MOGtag). A tobacco etch virus (TEV) protease cleavage site was incorporated to allow the removal of all tag sequences, leaving only the pure MOG1-125 extracellular domain. Here, we describe a simple protocol using only standard laboratory equipment to produce large quantities of pure MOGtag or MOG1-125. This protocol consistently generates over 200 mg of MOGtag protein. Immunization with either MOGtag or MOG1-125 generates an autoimmune response that includes pathogenic B cells that recognize the native mouse MOG.

Infectious Mononucleosis Triggers Generation of IgG Auto-Antibodies against Native Myelin Oligodendrocyte Glycoprotein.

A history of infectious mononucleosis (IM), symptomatic primary infection with the Epstein Barr virus, is associated with the development of autoimmune diseases and increases the risk to develop multiple sclerosis. Here, we hypothesized that immune activation during IM triggers autoreactive immune responses. Antibody responses towards cellular antigens using a HEp-2 based indirect immunofluorescence assay and native myelin oligodendrocyte glycoprotein (MOG) using a flow cytometry-based assay were determined in 35 patients with IM and in 23 control subjects. We detected frequent immunoglobulin M (IgM) reactivity to vimentin, a major constituent of the intermediate filament family of proteins, in IM patients (27/35; 77%) but rarely in control subjects (2/23; 9%). IgG autoantibodies binding to HEp-2 cells were absent in both groups. In contrast, IgG responses to native MOG, present in up to 40% of children with inflammatory demyelinating diseases of the central nervous system (CNS), were detectable in 7/35 (20%) patients with IM but not in control subjects. Normalization of anti-vimentin IgM levels to increased total IgM concentrations during IM resulted in loss of significant differences for anti-vimentin IgM titers. Anti-MOG specific IgG responses were still detectable in a subset of three out of 35 patients with IM (9%), even after normalization to increased total IgG levels. Vimentin-specific IgM and MOG-specific IgG responses decreased following clinical resolution of acute IM symptoms. We conclude from our data that MOG-specific memory B cells are activated in subset of patients with IM.

T Cell Epitope 119-132, but Not 35-55, Is the Immunodominant Encephalitogenic Determinant of the CNS Autoantigen, Myelin Oligodendrocyte Glycoprotein (P05.118)

Objective: To evaluate native full-length MOG for novel T cell epitopes. Background Amino acid (aa) residues 35-55 within the extracellular domain 1-117 of myelin oligodendrocyte glycoprotein (MOG) contain its only known encephalitogenic T cell determinant for C57BL/6 (H-2^b) mice, a strain frequently studied in the multiple sclerosis (MS) model, experimental autoimmune encephalomyelitis (EAE). Based upon studies showing that processing of native MOG is required for presentation of 35-55, we predicted that MOG contains additional T cell epitopes. Design/Methods: C57BL/6 mice were immunized with full-length (218 aa) murine (self) MOG or overlapping peptides encompassing its entire sequence in complete Freund9s adjuvant. Proliferation was measured by 3^H-thymidine incorporation. ELISPOT was used to measure frequency of epitope-specific IFN-γ-producing T cells that were generated by in vivo priming with full-length MOG. Results: Three novel T cell epitopes were discovered, an encephalitogenic determinant within transmembrane domain residues 119-132, and two discrete nonencephalitogenic determinants, p181-195 and p186-200, in the cytoplasmic domain. Clinical EAE, CNS inflammation and demyelination induced by p119-132 were equal, or greater, in severity than with p35-55. T cell recognition of MOG p119-132 was restricted by MHC II (I-A^b) molecules and p119-132 induced EAE in other H-2^b strains, but not in mice of other haplotypes. MOG p119-132-primed T cells, which produced higher levels of pathogenic Th1 and Th17 cytokines than p35-55-primed T cells, adoptively transferred EAE to naive recipients. Frequency of T cells that responded to p119-132 after immunization with full-length MOG was greater than to p35-55 or the non-encephalitogenic determinants, demonstrating that p119-132 is the immunodominant determinant. Conclusions: MOG p119-132, not p35-55, is the immunodominant encephalitogenic determinant of MOG. Not all T cell epitopes of a self antigen are pathogenic. Recognizing that MOG contains multiple encephalitogenic and non-encephalitogenic determinants permits testing tolerogenic approaches that target individual non-pathogenic or pathogenic T cell epitopes. Supported by: NIH and Boehringer-Ingelheim. Disclosure: Dr. Shetty has received research support from Boehringer Ingelheim. Dr. Gupta has received research support from Boehringer Ingelheim Pharmaceuticals, Inc. Dr. Weber has received personal compensation for activities with Hoffmann-LaRoche, Genentech, Inc., Novartis, Bayer Pharmaceuticals Corporation, Merck Serono, Biogen Idec and Teva Neuroscience as a speaker and/or participant on an advisory board. Dr. Weber has received research support from Teva Neuroscience. Dr. Molnarfi has nothing to disclose. Dr. Forsthuber has received research support from the National Institutes of Health. Dr. Sobel has received research support from the NIH. Dr. Bernard has nothing to disclose. Dr. Slavin has received personal compensation for activities with Boehringer Ingelheim as an employee. Dr. Slavin holds stock and/or stock options in Boehringer Ingelheim. Dr. Slavin has received research support from Boehringer Ingelheim. Dr. Zamvil has received personal compensation for activities with Biogen Idec, Teva Neuroscience and EMD Serono-Pfizer. Dr. Zamvil has received research support from the National Institutes of Health, National Multiple Sclerosis Society, the Maisin Foundation, the Guthy Jackson Charitable Foundation, Teva Neuroscience, and Boehringer Ingelheim Pharmaceuticals, Inc.

Complement activating antibodies to myelin oligodendrocyte glycoprotein in neuromyelitis optica and related disorders

BackgroundSerum autoantibodies against the water channel aquaporin-4 (AQP4) are important diagnostic biomarkers and pathogenic factors for neuromyelitis optica (NMO). However, AQP4-IgG are absent in 5-40% of all NMO patients and the target of the autoimmune response in these patients is unknown. Since recent studies indicate that autoimmune responses to myelin oligodendrocyte glycoprotein (MOG) can induce an NMO-like disease in experimental animal models, we speculate that MOG might be an autoantigen in AQP4-IgG seronegative NMO. Although high-titer autoantibodies to human native MOG were mainly detected in a subgroup of pediatric acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) patients, their role in NMO and High-risk NMO (HR-NMO; recurrent optic neuritis-rON or longitudinally extensive transverse myelitis-LETM) remains unresolved.ResultsWe analyzed patients with definite NMO (n = 45), HR-NMO (n = 53), ADEM (n = 33), clinically isolated syndromes presenting with myelitis or optic neuritis (CIS, n = 32), MS (n = 71) and controls (n = 101; 24 other neurological diseases-OND, 27 systemic lupus erythematosus-SLE and 50 healthy subjects) for serum IgG to MOG and AQP4. Furthermore, we investigated whether these antibodies can mediate complement dependent cytotoxicity (CDC). AQP4-IgG was found in patients with NMO (n = 43, 96%), HR-NMO (n = 32, 60%) and in one CIS patient (3%), but was absent in ADEM, MS and controls. High-titer MOG-IgG was found in patients with ADEM (n = 14, 42%), NMO (n = 3, 7%), HR-NMO (n = 7, 13%, 5 rON and 2 LETM), CIS (n = 2, 6%), MS (n = 2, 3%) and controls (n = 3, 3%, two SLE and one OND). Two of the three MOG-IgG positive NMO patients and all seven MOG-IgG positive HR-NMO patients were negative for AQP4-IgG. Thus, MOG-IgG were found in both AQP4-IgG seronegative NMO patients and seven of 21 (33%) AQP4-IgG negative HR-NMO patients. Antibodies to MOG and AQP4 were predominantly of the IgG1 subtype, and were able to mediate CDC at high-titer levels.ConclusionsWe could show for the first time that a subset of AQP4-IgG seronegative patients with NMO and HR-NMO exhibit a MOG-IgG mediated immune response, whereas MOG is not a target antigen in cases with an AQP4-directed humoral immune response.

Autoantibodies recognizing native MOG are closely associated with active demyelination but not with neuroinflammation in chronic EAE

It is important to find biomarkers for autoimmune inflammation and demyelination in the CNS to monitor disease status in patients with multiple sclerosis (MS). For this purpose, we determined the titers of antibodies (Ab) reacting with native myelin oligodendrocyte glycoprotein (MOG)-expressing cells to evaluate the disease activity of chronic experimental autoimmune encephalomyelitis (EAE) in rats and the relationship between anti-MOGcme (cell membrane-expressed MOG), Ab titers and clinical and pathological parameters were evaluated. Consequently, we found that elevation of anti-MOGcme Ab titers was associated with clinical severity, except for some cases in very late stages and with severe and widespread demyelination but with dominant inflammation. In contrast, antibodies detected by standard ELISA using recombinant MOG were elevated in both symptomatic and asymptomatic rats and were not associated with parameters such as inflammation and demyelination. Longitudinal examination of anti-MOGcme Ab titers in individual rats revealed that Ab titers accurately reflect disease activity. Furthermore, anti-MOGcme Ab titer was not elevated in acute EAE without demyelination. These findings suggest that autoantibodies reacting with native and glycosylated MOG play an important role in the progression of demyelinating diseases and could be biomarkers for monitoring the status of patients with MS.

Temporal dynamics of anti-MOG antibodies in CNS demyelinating diseases

Recent studies demonstrated the presence of autoantibodies to native myelin oligodendrocyte glycoprotein (MOG) in juvenile patients with acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS). However, so far no longitudinal studies on anti-MOG antibodies have been performed. Therefore, we determined serum and CSF antibodies against native human MOG in 266 pediatric and adult subjects with ADEM, clinically isolated syndrome (CIS), MS, other neurological diseases (OND) and healthy controls (HC) and longitudinal samples of 25 patients with ADEM, CIS, MS and OND using an immunofluorescence assay. We detected serum high-titer MOG IgG in 15/34 (44%) patients with ADEM, but only rarely in CIS (3/38, 8%), MS (2/89, 2%), OND (1/58, 2%) and HC (0/47). Longitudinal analysis of serum anti-MOG IgG showed different temporal dynamics of serum antibody responses in ADEM, CIS and MS and indicated an association of a favorable clinical outcome in ADEM with a decrease in antibody titers over time.

Antibody responses to EBV and native MOG in pediatric inflammatory demyelinating CNS diseases

Epstein-Barr virus (EBV) has been discussed as a possible causative agent in inflammatory demyelinating diseases of the CNS. Cross-reactivity between EBV and myelin proteins has been proposed as a potential mechanism by which EBV could elicit an autoimmune response targeting the CNS. Recently, high antibody titers to native myelin oligodendrocyte glycoprotein (nMOG) were found in children affected by the first inflammatory demyelinating event. The relation between antibody responses to EBV and nMOG has not been addressed in children so far. We investigated the occurrence of antibodies to nMOG, EBV nuclear antigen 1 (EBNA-1), and early antigen (EA) in a case-control study including children with acute disseminated encephalomyelitis (ADEM, n = 19), children with clinically isolated syndrome (CIS, n = 25), children with other neurologic diseases (n = 28), and healthy children (n = 30). Immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies against the extracellular part of nMOG were assessed by a cell-based assay, and EBV-specific IgG antibodies to EBNA-1 and IgM antibodies to EA were assessed by ELISA. Serum IgG antibodies to EBNA-1 were present in 43% of controls (25/58), 42% of children with ADEM (8/19), and 64% of children with CIS (16/25), whereas IgM antibodies to EA were detected in only 16% of children with ADEM (3/19). High antibody titers to nMOG were only found in children with ADEM and CIS but were not related to the seropositivity to EBV. Moreover, in EBV-seropositive children, we did not observe any correlation between anti-EBNA-1 and anti-nMOG IgG antibody titers. High serum immunoglobulin G titers to native myelin oligodendrocyte glycoprotein are found in a significant number of children affected by clinically isolated syndrome or acute disseminated encephalomyelitis. These antibodies are not related to the antibody response to Epstein-Barr virus.

Antibodies to Oligodendrocyte Glycoprotein in Children with ADEM

Antibodies to native myelin oligodendrocyte glycoprotein (nMOG) in 47 children during a first episode of CNS demyelination (acute disseminated encephalomyelitis [ADEM] in 19, and a clinical isolated syndrome [CIS] in 28) were investigated by a cell-based bioassay in a study at Children’s Hospital at Westmead, Sydney, Australia, and at the University of Munich, Germany.

Antibodies to native myelin oligodendrocyte glycoprotein in children with inflammatory demyelinating central nervous system disease

Myelin oligodendrocyte glycoprotein (MOG) is a candidate target antigen in demyelinating diseases of the central nervous system (CNS). Although MOG is encephalitogenic in different animal models, the relevance of this antigen in human autoimmune diseases of the CNS is still controversial. We investigated the occurrence and biological activity of antibodies to native MOG (nMOG) in 47 children during a first episode of CNS demyelination (acute disseminated encephalomyelitis [ADEM], n = 19 and clinical isolated syndrome [CIS], n = 28) by a cell-based bioassay. High serum immunoglobulin G (IgG) titers to nMOG were detected in 40% of children with CIS/ADEM but 0% of the control children affected by other neurological diseases, healthy children, or adults with inflammatory demyelinating diseases, respectively. By contrast, IgM antibodies to nMOG occurred in only 3 children affected by ADEM. Children with high anti-nMOG IgG titer were significantly younger than those with low IgG titer. Anti-nMOG IgG titers did not differ between the ADEM and CIS group, and did not predict conversion from CIS to MS during a mean 2-year follow-up. However, intrathecal IgG anti-MOG antibody synthesis was only seen in CIS children. IgG antibodies to nMOG not only bound to the extracellular domain of nMOG, but also induced natural killer cell-mediated killing of nMOG-expressing cells in vitro. Overall, these findings suggest nMOG as a major target of the humoral immune response in a subgroup of children affected by inflammatory demyelinating diseases of the CNS. Children may provide valuable insight into the earliest immune mechanisms of CNS demyelination.

Age-Dependent B Cell Autoimmunity to a Myelin Surface Antigen in Pediatric Multiple Sclerosis

Multiple sclerosis (MS) typically manifests in early to mid adulthood, but there is increasing recognition of pediatric-onset MS, aided by improvements in imaging techniques. The immunological mechanisms of disease are largely unexplored in pediatric-onset MS, in part because studies have historically focused on adult-onset disease. We investigated autoantibodies to myelin surface Ags in a large cohort of pediatric MS cases by flow cytometric labeling of transfectants that expressed different myelin proteins. Although Abs to native myelin oligodendrocyte glycoprotein (MOG) were uncommon among adult-onset patients, a subset of pediatric patients had serum Abs that brightly labeled the MOG transfectant. Abs to two other myelin surface Ags were largely absent. Affinity purification of MOG Abs as well as competition of binding with soluble MOG documented their binding specificity. Such affinity purified Abs labeled myelin and glial cells in human CNS white matter as well as myelinated axons in gray matter. The prevalence of such autoantibodies was highest among patients with a very early onset of MS: 38.7% of patients less than 10 years of age at disease onset had MOG Abs, compared with 14.7% of patients in the 10- to 18-year age group. B cell autoimmunity to this myelin surface Ag is therefore most common in patients with a very early onset of MS.

Spontaneous relapsing-remitting EAE in the SJL/J mouse: MOG-reactive transgenic T cells recruit endogenous MOG-specific B cells

We describe new T cell receptor (TCR) transgenic mice (relapsing-remitting [RR] mice) carrying a TCR specific for myelin oligodendrocyte glycoprotein (MOG) peptide 92–106 in the context of I-As. Backcrossed to the SJL/J background, most RR mice spontaneously develop RR experimental autoimmune encephalomyelitis (EAE) with episodes often altering between different central nervous system tissues like the cerebellum, optic nerve, and spinal cord. Development of spontaneous EAE depends on the presence of an intact B cell compartment and on the expression of MOG autoantigen. There is no spontaneous EAE development in B cell–depleted mice or in transgenic mice lacking MOG. Transgenic T cells seem to expand MOG autoreactive B cells from the endogenous repertoire. The expanded autoreactive B cells produce autoantibodies binding to a conformational epitope on the native MOG protein while ignoring the T cell target peptide. The secreted autoantibodies are pathogenic, enhancing demyelinating EAE episodes. RR mice constitute the first spontaneous animal model for the most common form of multiple sclerosis (MS), RR MS.

CD8 T Cell Responses to Myelin Oligodendrocyte Glycoprotein-Derived Peptides in Humanized HLA-A*0201-Transgenic Mice

Multiple sclerosis (MS) is a demyelinating inflammatory disease of the CNS. Though originally believed to be CD4-mediated, additional immune effector mechanisms, including myelin-specific CD8(+) T cells, are now proposed to participate in the pathophysiology of MS. To study the immunologic and encephalitogenic behavior of HLA-A*0201-binding myelin-derived epitopes in vivo, we used a humanized HLA-A*0201-transgenic mouse model. Eight HLA-A*0201-binding peptides derived from myelin oligodendrocyte glycoprotein (MOG), an immunodominant myelin self-Ag, were identified in silico. After establishing their relative affinity for HLA-A*0201 and their capacity to form stable complexes with HLA-A*0201 in vitro, their immunological characteristics were studied in HLA-A*0201-transgenic mice. Five MOG peptides, which bound stably to HLA-A*0201 exhibited strong immunogenicity by inducing a sizeable MOG-specific HLA-A*0201-restricted CD8(+) T cell response in vivo. Of these five candidate epitopes, four were processed by MOG-transfected RMA target cells and two peptides proved immunodominant in vivo in response to a plasmid-encoding native full-length MOG. One of the immunodominant MOG peptides (MOG(181)) generated a cytotoxic CD8(+) T cell response able to aggravate CD4(+)-mediated EAE. Therefore, this detailed in vivo characterization provides a hierarchy of candidate epitopes for MOG-specific CD8(+) T cell responses in HLA-A*0201 MS patients identifying the encephalitogenic MOG(181) epitope as a primary candidate.

Identification of a pathogenic antibody response to native myelin oligodendrocyte glycoprotein in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Although the cause of MS is still uncertain, many findings point toward an ongoing autoimmune response to myelin antigens. Because of its location on the outer surface of the myelin sheath and its pathogenicity in the experimental autoimmune encephalomyelitis model, myelin oligodendrocyte glycoprotein (MOG) is one of the potential disease-causing self antigens in MS. However, the role of MOG in the pathogenesis of MS has remained controversial. In this study we addressed the occurrence of autoantibodies to native MOG and its implication for demyelination and axonal loss in MS. We applied a high-sensitivity bioassay, which allowed detecting autoantibodies that bind to the extracellular part of native MOG. Antibodies, mostly IgG, were found in sera that bound with high affinity to strictly conformational epitopes of the extracellular domain of MOG. IgG but not IgM antibody titers to native MOG were significantly higher in MS patients compared with different control groups with the highest prevalence in primary progressive MS patients. Serum autoantibodies to native MOG induced death of MOG-expressing target cells in vitro. Serum from MS patients with high anti-MOG antibody titers stained white matter myelin in rat brain and enhanced demyelination and axonal damage when transferred to autoimmune encephalomyelitis animals. Overall these findings suggest a pathogenic antibody response to native MOG in a subgroup of MS patients.

Antibodies to native myelin oligodendrocyte glycoprotein are serologic markers of early inflammation in multiple sclerosis

Myelin oligodendrocyte glycoprotein (MOG) is an integral membrane protein expressed in CNS oligodendrocytes and outermost myelin lamellae. Anti-MOG Abs cause myelin destruction (demyelination) in animal models of multiple sclerosis (MS); however, such pathogenic Abs have not yet been characterized in humans. Here, a method that specifically detects IgG binding to human MOG in its native, membrane-embedded conformation on MOG-transfected mammalian cells was used to evaluate the significance of these auto Abs. Compared with healthy controls, native MOG-specific IgGs were most frequently found in serum of clinically isolated syndromes (P < 0.001) and relapsing-remitting MS (P < 0.01), only marginally in secondary progressive MS (P < 0.05), and not at all in primary progressive MS. We demonstrate that epitopes exposed in this cell-based assay are different from those exposed on the refolded, extracellular domain of human recombinant MOG tested by solid-phase ELISA. In marmoset monkeys induced to develop MS-like CNS inflammatory demyelination, IgG reactivity against the native membrane-bound MOG is always detected before clinical onset of disease (P < 0.0001), unlike that against other myelin constituents. We conclude that (i) epitopes displayed on native, glycosylated MOG expressed in vivo are early targets for pathogenic Abs; (ii) these Abs, which are not detected in solid-phase assays, might be the ones to play a pathogenic role in early MS with predominant inflammatory activity; and (iii) the cell-based assay provides a practical serologic marker for early detection of CNS autoimmune demyelination including its preclinical stage at least in the primate MS model.

Efficient presentation of myelin oligodendrocyte glycoprotein peptides but not protein by astrocytes from HLA-DR2 and HLA-DR4 transgenic mice

The role of astrocytes in the pathogenesis of multiple sclerosis (MS) is not well understood. Astrocytes may modulate the activity of pathogenic T cells by presenting myelin antigens in combination with pro- or anti-inflammatory signals. Astrocytes have been shown to present myelin basic protein (MBP) and proteolipid protein (PLP) to T cells, but it has remained unresolved whether astrocytes present myelin oligodendrocyte glycoprotein (MOG), which has been implicated as an important autoantigen in MS. Here, we asked whether astrocytes presented MOG to T cells. To closer model presentation of human MOG by astrocytes in MS patients, we generated astrocytes from transgenic mice expressing the MS-associated MHC class II alleles HLA-DR2 (DRB1*1501) and HLA-DR4 (DRB1*0401). The results show that IFN-γ-activated HLA-DR2 and HLA-DR4 expressing astrocytes efficiently presented immunodominant and subdominant MOG peptides to T cells. The hierarchy of the presented MOG epitopes was comparable to that of professional APCs, including dendritic cells and microglia. Importantly, astrocytes were poor at processing and presenting native MOG protein. Furthermore, astrocytes induced a mixed Th1/Th2 cytokine response in MOG-specific T cells, whereas dendritic cells induced a predominantly Th1 cell response. Collectively, the results suggest that astrocytes may modulate anti-MOG T cell responses in the CNS.

Antibodies against glycosylated native MOG are elevated in patients with multiple sclerosis

Antibodies against native glycosylated myelin-oligodendrocyte-glycoprotein (MOG) were measured by ELISA in patients with multiple sclerosis (MS) and controls. Anti-MOG IgM antibodies were elevated during the first demyelinating event. Higher MOG-specific IgG antibodies were found in patients during relapses and in secondary chronic progressive MS compared to patients in remission and healthy controls. Antibodies against native MOG may be a potential biomarker for MS.

Native myelin oligodendrocyte glycoprotein promotes severe chronic neurological disease and demyelination in Biozzi ABH mice

Myelin oligodendrocyte glycoprotein (MOG) is a powerful encephalitogen for experimental autoimmune demyelination. However, the use of MOG peptides or recombinant proteins representing part of the protein fails to fully address the possible pathogenic role of the full-length myelin-derived protein expressing post-translational modifications. Immunization of mice with central nervous system tissues from wild-type (WT) and MOG-deficient (MOG(-/-)) mice demonstrates that MOG in myelin is necessary for the development of chronic demyelinating experimental autoimmune encephalomyelitis (EAE) in mice. While immunization with WT spinal cord homogenate (SCH) resulted in a progressive EAE phenotype, MOG(-/-) SCH induced a mild self-limiting acute disease. Following acute EAE with MOG(-/-) SCH, mice developed T cell responses to recombinant mouse MOG (rmMOG), indicating that MOG released from myelin is antigenic; however, the lack of chronic disease indicates that such responses were not pathogenic. Chronic demyelinating EAE was observed when MOG(-/-) SCH was reconstituted with a dose of rmMOG comparable to MOG in myelin (2.5% of total white matter-derived protein). These data reveal that while immunization with the full-length post-translational modified form of MOG in myelin promotes the development of a more chronic autoimmune demyelinating neurological disease, MOG (and/or other myelin proteins) released from myelin during ongoing disease do not induce destructive autoimmunity.

Antibodies against glycosylated native MOG are elevated in patients with multiple sclerosis

Antibodies against native glycosylated myelin-oligodendrocyte-glycoprotein (MOG) were measured by ELISA in patients with multiple sclerosis (MS) and controls. Anti-MOG IgM antibodies were elevated during the first demyelinating event. Higher MOG-specific IgG antibodies were found in patients during relapses and in secondary chronic progressive MS compared to patients in remission and healthy controls. Antibodies against native MOG may be a potential biomarker for MS.