Antibodies to Total Brain Gangliosides: Titer and Specificity of Antisera

Polyclonal antibodies to ganglioside GM1 have been prepared and characterised by direct and competitive enzyme-linked immunoassay. An immunoglobulin fraction was prepared from a rabbit antisera showing high specificity and antibody titre for GM1 relative to the other major brain gangliosides. The anti-GM1 immunoglobulin fraction and B-cholera toxin specifically labelled neurons in primary cultures of embryonic chick dorsal root ganglia and there was a good correlation between the relative increase in binding of anti-GM1 immunoglobulin and B-cholera toxin following neuraminidase treatment of a variety of cell types. At antibody concentrations that show saturable binding to endogenous ganglioside in the neuronal membrane, the anti-GM1 immunoglobulin fraction did not interfere with the nerve growth factor (NGF)-mediated fibre outgrowth and neuronal survival as indexed by measurement of neurofilament protein levels. Similarly, at levels in excess of those shown to stimulate thymocyte proliferation, B-cholera toxin was also without effect. These data are not consistent with GM1 in the neuronal membrane functioning as a receptor molecule for NGF and/or other differentiation factors present in the tissue culture media.

Section: Discussionmentioning

confidence: 99%

Section: Characterisation Of Anti-gm1 Antibodies By Direct and Competmentioning

confidence: 99%

Ganglioside G_M1 Antibodies and B‐Cholera Toxin Bind Specifically to Embryonic Chick Dorsal Root Ganglion Neurons but Do Not Modulate Neurite Regeneration

Doherty

Walsh

1987

“…Antiganglioside sera were prepared as previously described (Rapport et al, 198Oa;Karpiak e t al., 1981). Antisera selected for study had serological titers above 300 against G,, ganglioside (complement-fixation with 4 C'so units of complement).…”

Section: Antiganglibside Serummentioning

confidence: 99%

Enhancement of Depolarization‐Induced Release of γ‐Aminobutyric Acid from Brain Slices by Antibodies to Ganglioside

Frieder

Rapport

1982

Self Cite

The effect of antibodies to GM1 ganglioside on release of neurotransmitters from rat brain slices was studied. Depolarization-induced (40 mM-KCl or veratrine) release of gamma-aminobutyric acid was markedly enhanced. Depolarization-induced release of norepinephrine was only slightly enhanced, whereas that of serotonin was unaffected. No effect on spontaneous release was observed for any of these three neurotransmitters. These results show that antibodies that can bind to synaptic membrane antigens may alter neurotransmitter release and that antibodies directed against GM1 ganglioside exhibit a measure of specificity in producing such an effect.

“…Gangliosides are a large family of substances with a high degree of structural similarity. Their low immunogenicity poses a special problem in obtaining conventional (polyclonal) antibodies specific for individual species (Marcus and Schwarting, 1976; Rapport et al, 1980). Therefore, the development of monoclonal antibodies for the study of ganglioside structure, function, and analysis is a desirable goal.…”

mentioning

confidence: 99%

“…Therefore, the development of monoclonal antibodies for the study of ganglioside structure, function, and analysis is a desirable goal. We have applied hybndoma methodology to obtain monoclonal antibodies to GM1 ganglioside for the following reasons: (a) Antibodies to G M l have been useful interventive agents in numerous biological studies (Karpiak et al, 1978(Karpiak et al, , 1981 Rapport et al, 1979). (b) GM1 alters various cellular processes and CNS functions studied both in vitro and in vivo, but the mechanisms of its action are not yet known.…”

mentioning

confidence: 99%

Preparation and Specificity of 11 Monoclonal Antibodies to G_M1 Ganglioside

Mahadik

Laev

Rapport

1986

Self Cite

Eleven monoclonal antibodies to GM1 ganglioside were prepared from hybridoma clones obtained by fusion of spleen cells from mice immunized with GM1 with mouse myeloma cells. When the reactivities of these 11 monoclonal antibodies were determined by enzyme‐linked immunosorbent assay with six glycosphingolipids (GM1, GD1a, GD1b, GT1b, GM2, and asialo‐GM1), they showed different degrees of specificity. From their reactivity patterns, they could be divided into three groups: Group 1, those that react only with GM1 (C3 and D3); Group 2, those that react predominantly with GM1 (C6, B6, D1, e1, g1, g9, and e12); and Group 3, those that show poor discrimination (h2 and A4). The clones differed in their biological activities.