Myelin Basic Protein Antibodies Research Articles

Microtubule associated protein (MAP1B) is present in cultured oligodendrocytes and co‐localizes with tubulin

Differentiation of oligodendrocytes is accompanied by the extension of processes and the assembly of the myelin membrane. It is likely that the cytoskeleton plays an important role in this process in terms of changes in cell shape, transport of myelin components, and organization of the myelin membrane. Oligodendrocytes contain microtubules (MT) which associate with other components of the cytoskeleton, and microtubule associated proteins (MAPs) may mediate some of these interactions. In this study we have shown the presence of MAP1B in oligodendrocytes grown in primary glial cultures by double-label immunofluorescence using antibodies to galactocerebroside (GC) and MAP1B. The staining of the cultures showed that GC-positive oligodendrocytes were also stained with MAP1B antibodies. However, MAP1B stain was limited to cell bodies and processes, whereas GC stain was also seen in flattened membrane sheets and punctate staining in processes. MAP1B staining was also compared with that of myelin proteolipid (PLP), myelin basic protein (MBP) and beta-tubulin in secondary glial cultures that were enriched for oligodendrocytes. The results showed a typical staining of cell bodies and membranous profiles using PLP antibodies, and the staining of cell bodies and flattened regions of membranous sheets by MBP antibodies. In contrast, both polyclonal and monoclonal antibodies to MAP1B showed a uniform diffuse staining of cell bodies, major processes, and fine interconnected processes. Double-labeling of the cells showed that MAP1B was co-localized with tubulin, but was not present in glial fibrillary acidic protein (GFAP)-positive astrocytes. Western and Northern blot analyses of primary glial cultures showed that MAP1B had a molecular mass of 320 kDa and a mRNA of 10 kb. These values are identical to those previously reported for brain MAP1B (Safaei and Fischer, 1989) and demonstrate the presence of MAP1B in oligodendrocytes.

A myelin basic protein antibody cascade in purified IgG from cerebrospinal fluid of multiple sclerosis patients

Immunoglobulin G (IgG) was purified by affinity chromatography from the CSF of multiple sclerosis (MS) patients and controls. In MS patients, the IgG fraction contains anti-myelin basic protein (anti-MBP), anti-MBP neutralizing antibody and an antibody which inhibits neutralization of anti-MBP. Anti-MBP was detected in patients with acute relapses, anti-MBP neutralizing antibody was present in patients in clinical remission and the inhibiting antibody was detected in patients with chronically progressing MS. A myelin basic protein antibody cascade could be involved in the mechanism of MS.

Retrobulbar optic neuritis in a two-year-old boy

We report a 2-year-4-month-old boy with retrobulbar optic neuritis. He had a sudden onset of impaired vision, which progressed to total blindness within a day. The visual evoked potential (VEP) showed no activity, but the electroretinogram was normal. Computed tomography (CT) and magnetic resonance imaging (MRI) showed no abnormal findings in the visual tract. The cerebrospinal fluid (CSF) myelin basic protein (MBP) level was elevated and serum anti-myelin antibody was positive. These findings suggested that optic neuritis in our patient was induced by retrobulbar demyelination, perhaps as a result of an autoimmune process. His visual impairment recovered gradually, but not completely, following oral prednisolone therapy. We have followed him for one year since discharge and have found neither recurrence of optic neuritis nor any other neurological disorders. Optic neuritis in children is rare and, to our knowledge, this patient is one of the youngest to be reported. This case suggests that autoimmune mechanisms may induce optic neuritis even in early childhood. In addition to VEP and MRI studies, the CSF MBP and serum anti-myelin antibody can be useful in the diagnosis and follow-up the patients with optic neuritis.

Detection of Antibodies Against Myelin Basic Protein and Increased Levels of HIV-IgG Antibodies and HIV Antigen after Solubilization of Immune Complexes in Sera and CSF of HIV Infected Patients

Fifteen HIV seropositive patients were studied. It was possible to enhance detection of HIV antigen and HIV and myelin basic protein (MBP) antibodies after dissociation of immune complexes by acid hydrolysis. HIV p24 antigen was then detected in four patients, three of whom were previously antigen negative. In 14 patients the treatment resulted in increased anti-HIV IgG subclass levels. Anti-MBP IgG was detected in 12 patients. Intrathecal synthesis of anti-MBP IgG subclasses was found in eight patients, five of whom had symptoms from the central nervous system.

Morphological distribution of MBP-like immunoreactivity in the brain during development

Myelin-basic protein (MBP)-like immunoreactivity was studied during development from postnatal day 1 to day 21 as a marker for the myelination process in the rat brain. Using monoclonal MBP antibodies, the caudo-rostral successive progression of MBP immunoreactivity was mapped in 1-, 7-, 14-, and 21-day-old animals using fluorescence microscopy of both coronal and sagittal sections. At 1 day of age, MBP-immunoreactive single fibers were seen in the lower brain stem, especially in formatio reticularis, whereas the rest of the brain was negative. In 1-week-old animals, MBP-positive fibers extended all the way into frontal cortex, but still in sparse arrays of single fibers with the largest number at the brain stem level. The 2-week stage showed a dramatic increase in the number of MBP-immunoreactive fibers. At the brain stem level, MBP-positive fiber plexuses were mixed with MBP-positive longitudinal axonal pathways. In cerebellar cortex, positive fibers began to radiate out from the white matter into the grey matter. A dense network of MBP-positive fibers was located in thalamus, and dense fluorescent fiber bundles were seen in capsula interna piercing through striatum. In cerebral cortex positive radiating fibers were considerably more numerous than at the previous stage. At the age of 3 weeks, MBP-immunoreactive fibers could be seen in networks and bundles in all parts of the brain. In the brain stem, a dense plexus of positive fibers filled formatio reticularis. In cortex cerebelli and cortex cerebri, a high density of radiating positive fibers was found. In striatum, a sparse distribution of single fibers was found in the neuropil surrounding the now strongly positive bundles of capsula interna.MBP-like immunoreactivity was followed during postnatal rat brain development and seemed to serve as a good indicator of progression of the myelinization process. With the excellent signal-to-noise ratio and the detailed morphological description of the distribution of MBP-like immunoreactivity, the present report can serve as a reference for studies of pathological disturbances of myelination in CNS as they relate to mechanical, chemical or hormonal perturbations.

Peripheral nerve demyelination in rabbits after inoculation with Freund's complete adjuvant alone or in combination with lipid haptens

The pathology of demyelination in rabbits with experimental allergic neuritis (EAN) or galactocerebroside-induced neuritis was compared to that in rabbits inoculated with either an emulsion of lipid haptens (gangliosides, lecithin and cholesterol) and Freund's complete adjuvant or Freund's complete adjuvant (FCA) alone. In rabbits inoculated with bovine peripheral myelin in FCA, perivenular demyelination associated with infiltrates of lymphocytes and macrophages occurred after 30 days, while those animals inoculated with galactocerebroside (GC) in Freund's adjuvant did not develop lesions until 60–90 days. GC rabbits had demyelination and severe nerve edema without cellular infiltrates. In rabbits inoculated with FCA alone, demyelination was restricted to ganglia and proximal nerve roots. Myelin basic protein (MBP) and GC antibodies from EAN, GC and lipid hapten-inoculated rabbits were detected by ELISA in sera at all post-inoculation time points. Appreciable P 0 and P 2 antibody titers were detected only in EAN animals. The results indicate that Freund's complete adjuvant alone or in combination with lipid haptens is capable of producing neuropathic effects in the rabbit independent of those produced by EAN or galactocerebroside neuritis.

A correlation between cerebrospinal fluid mylein basic protein and anti–myelin basic protein in multiple sclerosis patients

Free and bound levels of myelin basic protein (MBP) and anti-myelin basic protein (anti-MBP) antibodies were measured by radioimmunoassay in the cerebrospinal fluid of patients with multiple sclerosis who were experiencing acute exacerbations or progressing disease. In a cross-sectional study, free levels of MBP correlated with those of free anti-MBP, and bound MBP levels correlated with those of bound anti-MBP in both groups of patients with active disease. However, acute exacerbations of multiple sclerosis were characterized by higher free MBP and anti-MBP levels with lower levels of bound fractions. Conversely, patients with progressing disease had higher titers of bound than free fractions. Longitudinal studies of individual patients confirmed the association of higher titers of free anti-MBP with acute exacerbations and higher levels of bound anti-MBP with chronic progressing disease.

Relationship of adjuvants and swine influenza vaccine to experimental neuropathy in rabbits.

Experimental neuropathy, characterized by endoneurial edema and demyelination, was induced by inoculating rabbits with a combination of Freund's complete adjuvant (FCA), gangliosides, lecithin and cholesterol. A less severe demyelinating neuropathy could be induced by treatment with FCA alone but no significant change could be elicited by injection of swine influenza vaccine (SFV) alone. When FCA was combined with gangliosides, lecithins, cholesterol and SFV, neuropathy occurred, but the changes were less severe than if these agents were used without SFV. Sera were tested for myelin basic protein (MBP) and galactocerebroside (GC) antibodies in each experimental group. Neither SFV alone nor SFV combined with Freund's complete adjuvant, gangliosides, cholesterol and lecithin evoked significant antibody titers to MBP or GC. However, rabbits inoculated with FCA, gangliosides, lecithin and cholesterol had rising titers of antibody to both MBP and GC over the 3-month experimental period. One rabbit inoculated with FCA alone had significant antibody to MBP. The findings suggest that Freund's complete adjuvant alone can induce demyelination in the peripheral nerves of rabbits and that SFV may modulate the immune response acting either as an adjuvant or suppressant in the experimental demyelinating disease.

Serum and cerebrospinal fluid antibodies against myelin basic protein and their IgG subclass distribution in multiple sclerosis.

IgG class antibodies reactive with myelin basic protein (MBP) were determined by enzyme-linked immunosorbent assay (ELISA) in serum and cerebrospinal fluid (CSF) of 37 patients with multiple sclerosis and a control group of 32 patients with tension headache or psychoneurosis. Using standardised amounts of IgG from CSF and serum in ELISA, significantly higher mean antibody levels were found in CSF as well as in serum from the patients with multiple sclerosis. Ten (27%) of the multiple sclerosis CSF samples and 15 (41%) of the multiple sclerosis sera revealed anti MBP antibody levels exceeding 2 SD of the control group. Seven patients (19%) showed exclusive or higher levels of anti MBP antibodies in CSF, suggesting synthesis within the central nervous system. Analysis by ELISA for IgG subclasses of anti MBP antibodies revealed that they were restricted to IgG 1 in four patients and IgG 3 in one.

Major Central Nervous System Myelin Glycoprotein of the African Lungfish (Protopterus dolloi) Cross‐Reacts with Myelin Proteolipid Protein Antibodies, Indicating a Close Phylogenetic Relationship with Amphibians

CNS myelin was isolated from the spinal cord of the African lungfish Protopterus dolloi. Its proteins consisted of (1) two basic proteins (16,000 and 18,500 apparent Mr) that reacted with anti-human CNS myelin basic protein antibodies and (2) a major protein (29,000 apparent Mr) that stained with concanavalin A-horseradish peroxidase and bound to anti-rat CNS myelin proteolipid protein (PLP) antibodies. This dominant 29,000 Mr protein showed no reaction with antibodies against the major bovine PNS myelin glycoprotein P0. Following treatment with endoglycosidase F the 29,000 Mr protein was reduced in size to a 26,000 apparent Mr component that no longer bound concanavalin A but retained the anti-PLP reactivity. These results agree with a concanavalin A-binding oligosaccharide linked through asparagine to a protein backbone of PLP homology. The major 29,000 Mr lungfish CNS myelin protein was therefore termed g-PLP (glycosylated proteolipid protein). This is the first report demonstrating the occurrence of a PLP-cross-reactive protein in CNS myelin of a fish. It attests to the close phylogenetic relationship of lungfishes to amphibians. Amphibians were previously recognized as the oldest class bearing PLP in its CNS myelin.

Abstract 60. Myelin basic protein antibodies in catatonic schizophrenia

Abstract 60. Myelin basic protein antibodies in catatonic schizophrenia

Measurement of myelin basic protein and of anti-basic protein antibodies by ELISA utilizing biotinylated antibodies.

Immunoglobulins were conjugated to peroxidase by the biotin-avidin method and used in ELISA systems for measuring myelin basic protein (MBP) and anti-MBP antibodies. To measure concentration of MBP, microplate wells were coated with affinity purified rabbit anti-MBP antibodies and incubated with varying concentrations of MBP. Bound antigen was measured by incubating with biotinylated anti-MBP antibodies and avidin-peroxidase. As little as 0.2 ng/ml of MBP could be measured by this assay. To measure anti-MBP antibodies, microplate wells were coated with human MBP and incubated with varying concentrations of affinity purified rabbit anti-human MBP antibodies. Binding was measured by incubating with either peroxidase-conjugated anti-rabbit antibodies or biotinylated anti-rabbit antibodies and avidin peroxidase. The two methods were equally sensitive. The avidin-biotin method for enzyme conjugation promises to be a useful and versatile tool for ELISA systems.

An inhibition enzyme immunoassay for myelin basic protein

An improved Enzyme Immunoassay for Myelin Basic Protein is described. Myelin Basic Protein covalently attached to glass balls, and Myelin Basic Protein in samples compete with each other for binding of a peroxidase conjugated anti Myelin Basic Protein antibody. The peroxidase activity on the balls is then inversely proportional to the amount of Myelin Basic Protein in the sample. A detection limit of 0.6 ng/ml is demonstrated for diluent or spinal fluid. For plasma a dilution step increases this to 1.8 ng/ml. Both the coated balls and the peroxidase conjugate are stable for long periods. The assay requires no expensive equipment. Although the assay appears to be valid for subcellular fractions spinal fluid and plasma, successful detection of Myelin Basic Protection peptides in clinical samples may require careful selection of suitable antisera. The assay would be very suitable for eventual use with an appropriate monoclonal antibody.

Further studies on bacterial lipopolysaccharide-induced protection against experimental allergic encephalomyelitis in guinea pigs: Effects of chemical modifications

Bacterial lipopolysaccharide (LPS)-induced protection against experimental allergic encephalomyelitis (EAE) was studied in guinea pigs using chemically modified derivatives. Hydroxylaminolysis or alkaline hydrolysis of LPS, by which ester-linked fatty acids are removed from LPS, resulted in total loss of its mitogenic activity for B lymphocytes, and EAE-suppressive activity was simultaneously reduced. Similar diminished activity was observed in delayed-type skin reactions to myelin basic protein (BP) and anti-BP antibody production detected by passive hemagglutination and enzyme-linked immunosorbent assay (ELISA). These results indicate that the active site of LPS in suppressing EAE is in the lipid portion and that there exists a good correlation between the capacity of LPS to suppress EAE and its mitogenic activity.

The polyadenylated RNA directing the synthesis of the rat myelin basic proteins is present in both free and membrane-bound forebrain polyribosomes.

Free and membrane-bound polyribosomes were isolated from the forebrain of actively myelinating 24-day-old rats. The poly(A)+ RNA (polyadenylated RNA) extracted from both fractions was translated in vitro in reticulocyte lysates [Hall & Lim (1981) Biochem. J. 196. 327-336] in the presence or absence of a heterologous microsomal membrane fraction from dog pancreas. The rat myelin basic proteins synthesized in vitro were isolated by CM-cellulose chromatography and by immunoprecipitation with purified anti-(myelin basic protein) antibody. The large (mol.wt. 18 500) and small (mol.wt. 16 000) myelin basic proteins were translational products of poly(A)+ RNA from both free and membrane-bound polyribosomes. The identity of the myelin basic proteins was verified by analysis of peptides generated by the cathepsin D digestion of the immunoprecipitated proteins synthesized in vitro, in comparison with authentic rat myelin basic proteins. Although several other translational products of membrane-bound polyribosomal poly(A)+ RNA were modified when microsomal membranes were present during translation, molecular weights of the myelin basic proteins themselves were unchanged. The myelin basic proteins synthesized in vitro also did not differ significantly in size from the authentic myelin basic proteins, indicating that these membrane proteins are unlikely to be synthesized as substantially larger precursor molecules. The presence of the specific mRNA species on both free and membrane-bound polyribosomes is compatible with the extrinsic location of the myelin basic proteins on the cytoplasmic surface of the myelin membrane.

Alpha-fetoprotein Suppresses Experimental allergic Encephalomyelitis

Experimental allergic encephalomyelitis (EAE), induced in guinea pigs by immunization with myelin basic protein (MBP) or whole CNS homogenate was successfully treated, as well as partially prevented, by daily administration of fetal alpha-fetoprotein (alpha FP). alpha FP which is produced in high quantities during pregnancy can inhibit both the cell-mediated immune response to MBP and the binding of MBP antibody to the antigen in vitro. It has a non-specific immunosuppressive effect on both the cellular and humoral responses. It is suggested that the ability of alpha FP to suppress an experimental autoimmune disease, as presented in this model of EAE, indicates that clinical remissions of human autoimmune disease during pregnancy may be attributed to the effect of this natural substance.

Myelin basic protein serum factor. An endogenous neuroantigen influencing development of experimental allergic encephalomyelitis in Lewis rats.

Age-related concentrations of myelin basic protein serum factor (MBP-SF), an endogenous neuroantigen detected and quantitated by inhibition of binding of rat myelin basic protein (RMBP) antibody with 125I-RMBP reagent antigen and immunochemically indistinguishable from native RMBP in this respect, reach peak levels as high as 21 ng/microliter among 2-3-wk-old normal suckling Lewis rats. Levels then progressively decline to low, usually undetectable levels of less than or equal to 0.6 ng/microliter MBP-equivalents in adult animals by 7 wk of age. MBP-SF levels are inversely related to the age-related increasing capacity of maturing Lewis rats to develop experimental allergic encephalomyelitis (EAE) after sensitization to MBP of syngeneic, but not xenogeneic, origin. MBP-SF appears to be an endogenous neuroimmunoregulatory product of potential importance for immunologic tolerance to autologous RMBP in Lewis rats.

Cellular and humoral responses to myelin basic protein in multiple sclerosis: a dichotomy.

The macrophage migration inhibition factor (MIF) assay and a counterimmunodiffusion assay were utilized to measure immune responses to human myelin basic protein in 75 patients with multiple sclerosis (MS) and in 120 control subjects. Eight out of ten MS patients in acute exacerbation and one out of seventeen convalescent, but none of chronically ill MS patients gave positive results in the MIF test. Forty-six percent of the patients with negative MIF assays but only 22% of those with positive assays had positive antibody results. In the counterimmunodiffusion assay, myelin basic protein antibody was demonstrated in almost 2/3 of patients during convalescence but it was not present in those whose illness had been stable for 6 months or longer. While no correlation with the stage or duration of the illness was present in other disorders, in MS an inverse correlation with clinical activity and in vitro evidence of cellular sensitization to encephalitogenic basic protein was apparent.

Clearance of myelin basic protein from blood of normal and EAE rabbits.

The rate of clearance of porcine myelin basic protein (MBP) from plasma of rabbits was determined following intravenous injection of 20 mg MBP. The MBP level in the plasma was measured by a 2-site immunoradiometric assay with specific antibody to guinea pig MBP produced in rabbits. Plasma MBP-antibody levels were determined by competitive binding radioimmune assay (RIA). Unsensitized and those sensitized with complete Freund's adjuvant (CFA), with porcine MBP in CFA, and with whole porcine spinal cord in CFA were studied. Unsensitized and CFA sensitized rabbits exhibited maximum MBP levels in the plasma within two minutes after injection with rapid decrease to undetectable levels in one hour. Thirty-nine of the unsensitized (control) rabbits exhibited normal, rapid clearance and no subsequent physical signs of EAE while one of the control rabbits exhibited a slightly retarded clearance rate. Histologic examination of autopsy tissues from the control group revealed that five rabbits showed lesions which could be attributed to Encephalitozoan cuniculi or Toxoplasma and one rabbit autopsied 65 days after clearance had minimal EAE lesions. Rabbits sensitized with MBP exhibited a retarded rate of clearance at the acute stage of EAE and following recovery. Rabbits sensitized with whole spinal cord in CFA also exhibited a retarded rate of MBP clearance. Anti (MBP) antibodies were detected in the plasma of all rabbits which exhibited a retarded rate of MBP clearance. Significant rates of retardation were not detected until approximately three weeks after sensitization with CFA-MBP or CFA-spinal cord. While MBP antibody levels in most animals were not detected by the immunodiffusion technique, antibodies were demonstrated by RIA. The 20 mg MBP given intravenously is probably in great antigen excess and conducive to the formation of soluble MBP-anti (MBP) complexes in the blood.

Radioimmunological determination of myelin basic protein (MBP) and MBP-antibodies.

Optimal conditions for radioiodinating of MBP by the chloramine T method are described. Adsorption on CM cellulose was found to be the best way to separate ¹²⁵T-MBP from inorganic iodine. Iodination and purification can be performed in less than 30 min. The iodinated MBP was used for radioimmunological determination of antibodies against MBP and of MBP itself. The immunoreactivity of iodinated MBP was independent of the extent of iodination, by which an upper level of 8 radio iodine atoms/molecule could be reached. Therefore, it is possible to develop a radioimmunoassay of high sensitivity. The optimal conditions for formation of the antibody-MBP complex were investigated. The complex was isolated using gel filtration on Sephadex or dextran-coated charcoal. Both gave the same results, but the charcoal procedure is far more rapid. Antibody titration curves and MBP standard curves were performed. Bovine and human MBP, which differ from each other in molecular weight and amino acid sequence, were shown to give a complete cross-reaction with antibodies against human MBP. In a preliminary study in sera cerebrospinal fluids of patients with multiple sclerosis humural antibodies to human MBP could not be detected, whereas in serum of a patient with a second cerebrovascular accident MBP antibodies were found.