Anti-ganglioside antibodies in multiple sclerosis

A human IgM M-protein in a patient with unknown bleeding disorder binds to beta-galactosyl and beta-glucosyl residues

In a patient with an unknown bleeding disorder and an IgM lambda paraproteinemia, we demonstrated by thin-layer chromatography immunostaining and enzyme-linked immunosorbent assay that this protein specifically bound to a number of glycolipids and glycoproteins which have terminal beta-galactosyl or beta-glucosyl residues. Binding to galactosylceramide or glucosylceramide was inhibited by both galactosylceramide and glucosylceramide. From these studies, it is apparent that the M-protein recognized both beta-galactosyl and beta-glucosyl residues. This M-protein was also shown to prolong the partial thromboplastin time of normal plasma. Thus, this case represents an example of anti-carbohydrate specificity of an IgM M-protein in association with a spontaneous bleeding disorder.

Vaccines containing purified GM2 ganglioside elicit GM2 antibodies in melanoma patients

GM2, GD2, and GD3 gangliosides are expressed on the surface of human melanoma cells and represent potential targets for immunological control of melanoma growth by monoclonal antibodies and active immunization. The immunogenicity of GM2 was investigated by analyzing the humoral immune response of melanoma patients to vaccination with cell lines selected for high GM2 expression and with vaccines containing purified GM2. The whole-cell vaccine and vaccines containing purified GM2 and bacillus Calmette-Guérin (BCG) elicited GM2 antibody in a high proportion of patients, particularly in GM2/BCG-vaccinated patients pretreated with cyclophosphamide and given a GM2/BCG booster immunization. Vaccines containing purified GM2 and Salmonella minnesota R595 as the adjuvant were also effective, but only in patients pretreated with cyclophosphamide. GM2 antibodies in vaccinated patients were of the IgM class and were cytotoxic for GM2-positive targets in the presence of human complement.

Immunological relationship between a demyelinating RNA enveloped budding virus (Semliki Forest) and brain glycolipids

A monoclonal antibody (MAb) raised against central nervous system (CNS) myelin (212) and a MAb (308) raised against brain with Semliki Forest virus (SFV) were both found to react against the same CNS glycolipids. Both these MAbs were also found to react strongly with SFV and against certain brain glycolipid fractions in an immunosorbent assay (ELISA). This demonstrates the presence of common glycolipid antigens in the viral envelope and CNS myelin. MAb 212 had no SFV neutralising capacity and that of MAb 308 was not significant. However, MAb 212 inhibited the neutralisation of the virus by the MAbs (302, 307) specific to SFV proteins. The implications of these findings in relation to the viral induced CNS autoimmunity and persistence of virus in the CNS is discussed.

Derivation of ganglioside-specific T cell lines of suppressor or helper phenotype from cerebrospinal fluid of multiple sclerosis patients

In order to investigate the specificity of activated T cells in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS), we have cultured cells in the presence of mitogen-free IL-2 but without any antigen. Two T cell lines have been derived and showed specific reactivity to certain purified gangliosides (GM1, GD1a, GD1b and GQ1b). However, responses to other brain and viral antigens were not seen, and neither were T cell lines from peripheral blood lymphocytes (PBL) of normal, MS or other neurological disease patients stimulated by these gangliosides. Release of IL-2 could be detected after incubation of these CSF lines with specific gangliosides. One line exhibited predominantly helper/inducer (T4+) phenotype whilst the other was suppressor/cytotoxic (T8+), and further analysis indicated it could be of the suppressor phenotype. These data may have implications for T cell-induced demyelination in MS.

Anti-glycolipid antibodies and their immune complexes in multiple sclerosis

Antibody titers against myelin constituents in sera and CSF of patients with multiple sclerosis (MS) were examined by a solid-phase radioimmunoassay. Anti-GM4 and anti-galactocerebroside antibody titers were significantly elevated in the CSF of MS patients, but not anti-GM1 and anti-myelin basic protein antibodies. In sera of MS patients, the titers of antibodies against these myelin constituents were not elevated. Total IgG level was also significantly elevated in the CSF, but not in the sera of MS patients. Immune complexes from the CSF of MS patients were dissociated by acid-ultrafiltration and assayed for antibodies to GM4, GM1, and galactocerebroside. Anti-GM4 and antigalactocerebroside antibody titers were significantly enhanced after acid dissociation and ultrafiltration. These data suggest that antibodies of the IgG class against GM4 and galactocerebroside are present in CSF of MS patients, and a significant number of them exist as immune complexes with their corresponding glycolipid antigens.

Immunoelectron-microscopical labelling of glycolipids in the envelope of a demyelinating brain-derived RNA virus (Semliki Forest) by anti-glycolipid sera

Immunoelectron-microscopical techniques using gold-labelled antibodies were used to localize the glycolipids ganglioside, glucocerebroside and galactocerebroside, and spike glycoprotein antigens, in the envelope of the RNA virus Semliki Forest which had replicated in mouse brain cell cultures. The demonstration of host cell membrane glycolipid antigens in viruses is discussed in relation to the possibility of an autoimmune reaction to central nervous system cells.

Effect of antiglycolipid antisera on the lipid composition of cultured mouse spinal cords

To examine the effect of antiglycolipid antibodies on demyelination, myelinated cultures of embryonic mouse spinal cords were treated by antigalactocerebroside (anti-GC), anti-GM1; and anti-GM4 antisera, and the lipid composition of the cultures were studied. The anti-GC antiserum-treated cultures, which exhibited severe morphologic signs of demyelination, revealed a significant reduction of cerebroside. The anti-GM4 or anti-GM1 antiserum-treated cultures, which exhibited mild degrees of demyelination, also had low contents of cerebroside. These results support our previous data showing that antiglycolipid antibodies cause demyelination in cultured mouse spinal cords, and suggest a possible role of myelin-specific glycolipids in the demyelination process.

Ganglioside GM1, a molecular target for immunological and toxic attacks: similarity of neuropathological lesions induced by ganglioside-antiserum and cholera toxin

Ganglioside-antisera, the ganglioside GM1-ligands, cholera toxin (CT), and CT subunit B, respectively, were injected into the lumbosacral subarachnoid space of normal rats. The cytotoxic effects of the injected compounds on the peripheral and central nervous system were investigated by light and electron microscopy; the severity of CNS lesions was evaluated by quantitation of macrophages containing debris. In contrast to control sera and GM2-antiserum, antisera against a mixture of the major brain gangliosides GM1, GD1a, GD1b, and GT1b (MaBG) or against GM1 induced demyelination in spinal roots and spinal cord, as well as alterations of astroglia. CT induced the same cytotoxic effects as MaBG- and GM1-antisera, whereas CT subunit B was without effect. The ineffectiveness of GM2-antiserum is obviously due to the very low concentration of the specific binding target, GM2, on cell surfaces; that of CT subunit B to the lack of the cytotoxic operator, subunit A. Our results indicate that a similar pattern of neuropathological lesions may be effected by different cytotoxic mechanisms through attachment of the cytotoxic agent onto the cell surface via a common target molecule, and further substantiate the role of GM1-antibodies in the pathogenesis of demyelination.

Complement-dependent immune damage to liposomes containing gangliosides

Rabbit antiserum against mixed beef brain gangliosides served as an excellent source of antibodies to gangliosides GM1, GM3, GD1a, GD1b, and GT1b. Immune potency of antiserum was determined by complement-dependent damage to liposomes containing gangliosides as antigens. Antibody levels in antiserum to mixed gangliosides, when tested against individual gangliosides, were equivalent or superior to the levels obtained by immunization of rabbits with purified individual gangliosides. Naturally occurring antibodies to GM1, GD1b, and GM3 were observed in preimmunization sera. The levels of these natural antibodies, although easily high enough to serve as antiserum sources for liposome assay, were increased substantially following immunization. High titers of antibodies to GM1 and GD1b were observed in certain individual guinea pig sera, and selection of individual non-reacting guinea pig sera was necessary in order to obtain suitable complement sources when testing rabbit antibodies to liposomal GM1 and GD1b. The maximum plateau level of trapped glucose release from liposomes in the presence of saturating levels of antigen, antiserum, and complement was influenced strongly both by the method of removing untrapped glucose during liposome preparation and by the type of ganglioside incorporated into the lipid bilayer.

Antiglycolipid antibodies in normal and pathologic human sera and synovial fluids

Antiglycolipid antibodies were measured in normal and pathologic sera and synovial fluids by means of a modified microplate method of complement-mediated immune lysis of fluorescent dye-trapped liposomes. All sera of normal subjects had antibodies against globopentaosylceramide (IV3 GalNAcGbOse4Cer), ganglioside GM1, gangliotriaosylceramide, gangliotetraosylceramide, and galactosylneolactotetraosylceramide antigens. Most sera of normal subjects had antibodies against lactotriaosylceramide, N-glycolylneuraminosyl-neolactotetraosylceramide (NeuGcnLcOse4Cer), GM3 ganglioside with N-glycolylneuraminic acid (NeuGcGM3) and GD1a antigens. Differences of titers against IV3GalNAcGbOse4Cer, neolactotetraosylceramide, NeuGcGM3 and NeuGcnLcOse4Cer antigens were observed between sera of normal subjects and pathologic sera from cases of leukemias, lymphomas, several autoimmune diseases and liver diseases.

Antisera to different glycolipids induce myelin alterations in mouse spinal cord tissue cultures

To study the demyelinative effects of antibodies to glycolipids, well-myelinated cultures of mouse spinal cord tissue were exposed to antisera against galactocerebroside and two gangliosides (GM1 and GM4), as well as to anti-white matter antiserum. The demyelinative process was evaluated by morphologic and biochemical techniques. Cultures exposed to anti-white matter and anti-galactocerebroside antisera showed the most marked changes. These consisted of a decrease in the number of oligodendroglial cells and dissolution and phagocytosis of myelin. Concomitantly, the activity of 2',3'-cyclic nucleotide-3'-phosphohydrolase (CNPase) was decreased by 60-70%. This occurred within 24 h of exposure to a relatively low concentration of serum (10%). Cultures exposed to anti-GM1 and anti-GM4 antisera showed similar changes but to a lesser degree. The CNPase activity was decreased about 30% within 48 h of exposure to a 25% concentration of these antisera. This diminution represents about a 20% loss of myelin, an observation corroborated by electron microscopy where myelin but not oligodendroglial cell loss was observed. Therefore, in addition to anti-galactocerebroside activity, which was previously found to be the major antibody responsible for the demyelinating activity induced by anti-whole CNS tissue antiserum, these data suggest that antibodies to gangliosides like GM1 and GM4 might also play a role in immune-mediated demyelination, including perhaps, the human demyelinating diseases.

Immunogenicity of melanoma-associated gangliosides in cancer patients

The immunogenicity of gangliosides found on human melanoma cells was determined from sera of 26 melanoma patients who were immunized every 1-4 weeks for 4 months with tumor-cell vaccine (TCV) prepared from cultured melanoma cells. Total lipid-bound sialic acid in the gangliosides isolated from TCV was 0.38 mumol/10(8) cells, and was distributed as follows: 44.8% to GM3, 44.2% to GD3, 5.6% to GM2, and 4.6% to GD2. Sera were tested at monthly intervals for antibodies to each ganglioside by ELISA with purified gangliosides as the antigen source. The immunologic specificity of the antibody was confirmed by absorption tests. None of the 26 patients had detectable anti-GM3, anti-GD3, or anti-GD2 antibodies before immunization, although anti-GM2 antibody was detected in 3 patients. After immunization, 2 patients developed IgM anti-GD2, 10 developed IgM anti-GM2, and 2 developed IgG anti-GM2 antibodies. No patient developed detectable anti-GM3 or anti-GD3 antibodies. These results indicate that both GD2 and GM2 expressed on human melanoma cells are immunogenic in humans, although GM2 appears to be more immunogenic. The other two gangliosides, GM3 and GD3, are present in human sera and in human normal tissues, and thus immunologic tolerance may have been established against these gangliosides. Alternatively, circulating GM3 and GD3 may have neutralized anti-GM3 and anti-GD3 antibodies, if any were induced by TCV immunization.

Galactocerebroside antiserum causes demyelination of cat optic nerve

A model of immune-mediated optic nerve demyelination is described. Micro-injection of small volumes (less than 5 microliter) of high titer polyclonal anti-Gal-C serum into the cat optic nerve resulted in a focal, highly selective demyelinative lesion followed by remyelination. Demyelination appears to be due to a dual effect on myelin and on oligodendrocytes. The numbers of these cells within the lesion were initially reduced but subsequently increased as remyelination occurred.

Abnormalities of serum and plasma components in patients with multiple sclerosis

Qualitative and quantitative abnormalities in protein and non-protein components of serum and plasma in patients with multiple sclerosis have been the subjects of numerous reports. In this review many of the more recent observations are documented and evaluated. It is concluded that at present the welter of information that has been gathered does not contribute in any major, coherent way to our understanding of the etiology or pathogenesis of the disorder. Several of the abnormalities that have been observed may be future candidates for biochemical markers for multiple sclerosis; at present none is sufficiently reliable, distinctive or easily performed to warrant the status of a useful diagnostic or prognostic test.

Immune responses to myelin antigens in multiple sclerosis

Multiple sclerosis is considered to be a putative immunopathologic disease and there has been considerable effort over the years to prove an autoimmune etiology for it. To date, the evidence is all indirect and there is no proof of either antibody and/or cell-mediated hypersensitivity to any single identifiable CNS constituent whether a constituent of normal CNS or specific to the CNS of MS patients.

Multiple sclerosis immune complexes: an analysis of component antigens and antibodies

Serum immune complexes were isolated from 21 patients with multiple sclerosis and 23 control subjects, who were normal or had other neurological diseases, and then probed for neurotropic viral and brain-reactive components. Multiple sclerosis complexes contained antibody to herpes simplex (13 cases), measles (8 cases), cytomegalovirus (5 cases), and rubella virus (5 cases). In some complexes, herpes simplex or cytomegalovirus antigen was detected along with antibody. Myelin basic protein or antibody to myelin basic protein was found in the complexes of 7 patients with multiple sclerosis and 2 patients with other neurological diseases. Serum complexes containing antibody reactive with galactocerebroside and ganglioside were present in 12 patients with multiple sclerosis and 3 with other neurological diseases. Over 60% of the multiple sclerosis group had IgM and IgA serum complexes, including 5 patients with very high IgA complex levels. This study suggests that patients with multiple sclerosis have ongoing systemic virus production with resultant immune complex formation. In addition, they often have serum complexes that contain brain-reactive components.

Antibodies to glycosphingolipids in patients with multiple sclerosis

Antibodies to one or more glycosphingolipids were detected by means of a liposome lysis assay in the sera of 60/81 patients with multiple sclerosis, 24/42 patients with systemic lupus erythematosus and in the majority of patients with cranial trauma or cerebrovascular accidents. Antibodies against ganglioside GM1 and asialo GM1 were found most commonly and they were frequently present in the same sera. Among patients whose sera contained antibodies to glycolipids, anti-GM1 alone occurred more frequently in patients with multiple sclerosis (14/59) than in systemic lupus erythematosus (1/22; p = 0.045) and antiasialo GM1 alone was more common in patients with lupus (9/22) than in patients with multiple sclerosis (8/59, p = 0.007). In 10 sera analyzed, all of the antibodies against these two glycolipids were of the IgM class, and some fluctuation in antibody titers was noted over a three-month period. The role of these antibodies in the initiation or perpetuation of inflammatory diseases of the central nervous system remains to be determined.

Immune lysis of lipid vesicles containing myelin basic protein or glycolipid antigens by multiple sclerosis and normal sera

We have compared the reactivity of sera from 34 multiple sclerosis (MS) patients and 32 normal (N) individuals with lipid vesicles containing myelin basic protein (BP) and several glycolipids reconstituted into a membrane environment. The ability of the sera to cause complement-mediated lysis of lipid vesicles containing these antigens was determined by measuring the release of a water-soluble spin label, tempocholine chloride, from the height of its electron spin resonance spectrum. Only 4 MS sera caused lysis of BP-containing vesicles which was comparable to that produced by specific antibody to BP. A number of both MS and N sera caused significant lysis of vesicles containing GM1 ganglioside or digalactosyldiglyceride. A few MS and N sera also caused significant lysis of vesicles containing GM2, GT1 and GD1a gangliosides. However, in no case was there a statistically significant difference between the mean lysis produced by MS and N sera. There was some overlap between the specific MS and N sera reactive to vesicles containing BP, GM1, GM2, and DGDG while a completely different group of MS and N sera were reactive to GT1 and GD1a gangliosides. This suggested that there was either antigenic cross reactivity between the two groups of glycolipids or two different origins of the immune response to the two groups of antigens. It was concluded that antibody-dependent complement fixation by these particular antigens, in the kind of lipid environment used, is not characteristic of or specific to MS.

A review of the immunogenic and immuno-modulatory properties of glycosphingolipids

This review summarizes recent data concerning the immunogenicity and immunomodulatory properties of glycosphingolipids. Many murine monoclonal antibodies that react with glycosphingolipids have been described recently. Most of these antibodies have been elicited by immunization with tumor cells and they may also bind to glycoproteins that contain similar carbohydrate sequences. Immunization with a variety of tissues, murine teratocarcinomas, myeloid leukemia, and carcinomas of the human lung, colon and stomach, has elicited antibodies that react with the sugar sequence Gal beta 1-4[Fuc alpha 1-3]GlcNAc beta 1-3Gal----. The suppression of lymphocyte responses to mitogens and antigens by gangliosides in vitro has led to suggestions that these glycolipids possess immunodulatory properties in vivo. The in vitro studies were performed by incubating mononuclear cells with either dispersions of pure gangliosides or ganglioside-containing liposomes. In vivo gangliosides are found only in cell membranes or in lipoproteins, where they represent a small mole percent of total lipids, and there is little information about the transfer of gangliosides from lipoproteins to cells in vivo. A role for gangliosides as modulators of the immune response is an interesting possibility that is not supported by physiologically relevant data at present.

Immunological expression of gangliosides in multiple sclerosis and in a demyelinating model disease in rabbits

Accumulating evidence suggests that the process of demyelination in MS might involve an autoimmune response to one or more myelin components. A combination of myelin basic protein and myelin haptens was considered as possibly enhancing a cellular or humoral autoimmune reaction in MS. In line with this motion we have used an in-vitro E-rosette assay that correlates with in-vivo delayed hypersensitivity to demonstrate specific immunologic sensitivity of lymphocytes from MS patients to polysialogangliosides. A recent report that only lymphocytes from patients in relapse, but not in remission, are primed by gangliosides, underscores the relevance of the antigenic expression of gangliosides during the active pathological phase of the disease. The antigenic capacity of gangliosides to induce upon immunization a neurological disorder featured by demyelination in the CNS was demonstrated in rabbits. This and previous reports on the induction of peripheral demyelination in rabbits immunized with gangliosides will be further analyzed to gain insight on the possible role of these myelin lipid components as targets for an autoimmune mechanism in MS.

Can viral envelope glycolipids produce auto-immunity, with reference to the CNS and multiple sclerosis?

Many viruses, with lipid envelopes derived from the host cell membranes, have been implicated in the aetiology of multiple sclerosis (MS), and epidemiological studies support an infectious agent. Alternatively the disease is thought by other workers to be auto-immune in nature, and recently much attention has been focused on immunological sensitivity to glycolipids in MS patients. In this paper it is proposed that CNS demyelination could arise in susceptible individuals (HLA type) from an immune response to glycolipids, triggered by the carrier effect of one or more enveloped neurotropic viruses.

Differential expression of gangliosides on the surfaces of myelinated nerve fibers

The binding of cholera and tetanus toxins to receptors on the surfaces of teased nerve fibers was used to localize GM1 and G1b-series gangliosides, respectively, by immunocytochemical methods. Native fibers and fibers treated with various hydrolytic enzymes to degrade specific surface components were studied. With native fibers, both toxins bound abundantly to nodes of Ranvier and poorly to the most external, internodal Schwann cell surfaces. Treatment of the fibers with proteases, hyaluronidase, and chondroitin ABC lyase neither eliminated receptors at the nodes nor unmasked receptors over the internodes. The axolemma underlying the paranodal or internodal myelin, exposed by extensive treatment with protease, bound both toxins in large amounts. Neuraminidase action induced cholera toxin receptors on the Schwann cell surface; these receptors were insensitive to protease. The results indicate that GM1 and G1b-series gangliosides are predominantly localized to axonal and glial structures of the node of Ranvier and to paranodal/internodal Axolemma, and that polysialogangliosides not of the G1b-series are present on the internodal Schwann cell surface.

Immune reactivity against membranes containing ganglioside GM1 in chronic-progressive multiple sclerosis: observation by spin-membrane immunoassay

A spin-membrane immunoassay has been employed to examine the immune reactivity of whole serum from patients with chronic-progressive multiple sclerosis (CPMS) against liposomes containing ganglioside GM1. Exposure to serum resulted in complement-mediated lysis of the GM1-liposomes. No lysis occurred with liposomes devoid of ganglioside. The mean (+/- S.E.M.) lysis values were 52.6 (+/- 9.8)% for fifteen CPMS patients and 32.9 (+/- 7.2)% for nine controls. The difference between the means was highly significant (student's t-test, P less than 0.0001), indicating increased anti-ganglioside immunity in patients with CPMS.

Chronic relapsing experimental allergic encephalomyelitis: its value as an experimental model for multiple sclerosis

Comparison of the pathohistology of chronic relapsing experimental allergic encephalomyelitis (CR-EAE) and multiple sclerosis (MS) reveals a close similarity. Thus, CR-EAE appears to be a valuable model for the study of pathogenetic factors leading to the formation of MS lesions, although the induction of the disease may be different (active sensitization with CNS antigens and adjuvant in CR-EAE versus unknown etiology in MS). CR-EAE furthermore mimicks the pathohistological patterns of other related human inflammatory demyelinating diseases (i.e., acute perivenous leukoencephalomyelitis and acute hemorrhagic leukoencephalomyelitis). The expression of an acute, predominantly inflammatory versus chronic inflammatory demyelinating disease in this model depends upon the time interval between sensitization and sampling of the animals. Recent evidence is discussed that a cooperation between cellular and humoral immune mechanisms, directed against multiple CNS antigens, is responsible for the formation of large demyelinated plaques in EAE and MS.

Etiology and pathogenesis of monophasic and relapsing inflammatory demyelination - human and experimental

The close similarity of the CNS lesions in cr-EAE and MS renders this model especially valuable for the study of pathogenetic factors, leading to the formation of inflammatory demyelinated plaques. Recent evidence indicates, that various immune reactions, directed against different CNS antigens cooperate in the formation of the plaques. Furthermore it is discussed, that a combination of virus infection and autoimmunity may result in similarity structured lesions. It is thus propose that multiple different etiologic factors (autoimmune as well as exogenous events) may lead to the clinical pathohistological syndrome of multiple sclerosis.

Preparation of anti-GM4 antiserum and its assay by a solid-phase radioimmunoassay

Anti-GM4 antiserum was prepared from rabbits by immunization with pure human brain GM4 ganglioside in complete Freund's adjuvant and methylated bovine serum albumin. None of the immunized animals developed any clinically apparent neurological dysfunction. The antiserum titer and specificity were analyzed by double immunodiffusion and a novel solid-phase radioimmunoassay (RIA). In the latter procedure, microtiter plate wells were coated first with the glycolipid antigen, followed by sequential application of antiserum and [125I]-Staphylococcal Protein A. The absorbed radioactivity in the well was then counted. Employing the RIA procedure, anti-GM4 antibody achieved a titer of 1:1600. The antiserum also exhibited a high degree of specificity to GM4; cross-reactivity with glycolipids of similar structure was negligible. The production of highly specific antiserum to GM4 and the feasibility of detecting antibodies to glycolipid antigens by a convenient solid-phase RIA should be useful to further study the biological and immunological roles of GM4 and other glycolipids in the central nervous system.

Sensitization of cerebrospinal fluid and peripheral blood lymphocytes to myelin basic protein in multiple sclerosis

Cerebrospinal fluid (CSF) and peripheral blood (PB) lymphocyte sensitization to rabbit myelin basic protein (MBP) in 44 multiple sclerosis (MS) patients, 21 patients with other neurological diseases (OND) and 14 persons with neurosis was studied with the antigen-active rosette forming cells (Ag-ARFC) assay. The frequency of sensitization of CSF lymphocytes to MBP in groups of MS patients in the relapse stage and the chronic progressive stage was higher than in the group of MS patients in the stable stage and the OND patients. None of the healthy subjects showed a positive reaction with MBP. In BP there were no differences in the incidence of sensitization to MBP between patients in various stages of the disease, but it was higher than in the group of patients with OND and neuroses. In the patients who had suffered from MS for less than 4 years, sensitization to MBP was more common in CSF lymphocytes than in BP lymphocytes. The results suggest that primary sensitization to MBP occurs in CSF, and is probably secondary to myelin damage. However at present it is difficult to determine the extent to which sensitization of CSF and PB lymphocytes to MBP play a role in further demyelination processes.

Elevated ganglioside concentration in serum and peripheral blood lymphocytes from multiple sclerosis patients in remission

The ganglioside concentration in pooled serum from 20 patients with clinically definite multiple sclerosis (MS) was determined and compared with that in pooled serum from a similar number of healthy blood donors. There as a significant increase in the concentration of ganglioside-bound sialic acid from 691 +/- 57 micrograms/100 ml in the control sera to 926 +/-m 83 micrograms 100 ml in MS patients' sera. The profile of individual gangliosides in the two groups was identical, the four main structures being GM3, GD3, and GD1a and GT1b. The ganglioside pattern and concentration in peripheral blood lymphocytes derived from MS patients and controls was identical with the predominant GM3, and small proportions of Gd3. MS lymphocytes also showed a 39% increase in ganglioside content over control lymphocytes. The implication of such pronounced ganglioside increases is discussed with regard to the impaired immunocompetence of lymphocytes reported in MS.

Multi-sialo brain gangliosides are powerful stimulators of active E-rosetting lymphocytes from multiple sclerosis patients

Peripheral blood T lymphocytes from all of 14 patients with clinically definite multiple sclerosis (MS) were significantly stimulated by MS brain gangliosides in the active rosetting of sheep erythrocytes. Fractionated mono- and disialogangliosides were devoid of any stimulating effect on MS lymphocytes whereas the trisialoganglioside GT1 and to a greater extent the tetrasialoganglioside GQ1b were fully effective at a dose as low as 2 x 10(-18) moles. Gangliosides extracted from MS brains or from MS brain myelin were far more effective than gangliosides derived from control human brains or from bovine and mouse brains, suggesting the importance of highly sialylated gangliosides occurring to a greater extent in MS brain as previously reported. Lymphocytes from only 3 out of 24 other neurological patients were stimulated by the slow migrating gangliosides in the same way, but none of 32 healthy subjects responded to these gangliosides in the active E-rosette test. Lymphocytes from 5 to 8 patients with unilateral optic neuritis reacted positively to brain gangliosides by rosette formation, several weeks before a similar reaction to myelin basic protein was evident. Our data are compatible with a release of gangliosides during demyelination or other CNS degenerative processes occurring in multiple sclerosis.

Antibodies to viral and non-viral antigens in subacute sclerosing panencephalitis and multiple sclerosis demonstrated by thin-layer polyacrylamide gel isoelectric focusing, antigen immunofixation and autoradiography

Antibody activity in IgG zones separated by thin-layer polyacrylamide gel isoelectric focusing (PAG IEF) was determined in 3 patients with subacute sclerosing panencephalitis (SSPE), 4 patients with multiple sclerosis (MS) and 4 subjects with psychosomatic disorders, using antigen immunofixation and autoradiography. Viral (measles herpes simplex type 1, mumps) and non-viral (purified bovine myelin, bovine myelin basic protein, bovine oligodendrocytes, MS and normal human brain extract) were used as antigens. All oligoclonal and some of the polyclonal CSF IgG zones in the patients with SSPE contained measles virus antibodies, as did some of the oligoclonal and polyclonal CSF IgG zones in 3 of the patients with MS. No antibodies were detectable in CSF or serum IgG zones against any of the non-viral antigens tested.

Experimental allergic neuritis induced by galactocerebroside

Experimental allergic neuritis (EAN), an animal model of human demyelinative neuritis, was induced by sensitization with galactocerebroside, a glycolipid hapten common in central and peripheral nervous system myelin. Between two months and one year after the initial sensitization, 11 of 24 rabbits immunized repeatedly with bovine brain galactocerebroside (GC) in complete Freund's adjuvant developed a neurological disorder manifested by flaccid quadriparesis, limb hypesthesia, and respiratory paralysis. Seventeen of 20 autopsied rabbits, including all those with clinical illness, had small multiple perivascular foci of demyelinative lesions in roots, dorsal root ganglia, proximal peripheral nerves adjacent to ganglia, and, less frequently, in distal nerves. No change was found in the central nervous system. Demyelination started around venules, with splitting and vesiculation of the outer myelin sheaths of adjacent fibers, and later progressed to form confluent lesions. The lesions were associated with infiltration of phagocytic mononuclear cells, mostly macrophages, which insinuated themselves between myelin lamellae, phagocytized myelin, and subsequently denuded axons. Perivenular infiltration of small lymphocytes, comparable to that seen in whole nerve- induced EAN, was not encountered. The distribution of demyelinative lesions seems to correspond to areas known to have a defective blood-nerve barrier.