Overexpression of GD1a Ganglioside Sensitizes Motor Nerve Terminals to Anti-GD1a Antibody-Mediated Injury in a Model of Acute Motor Axonal Neuropathy

Abstract

Anti-GD1a ganglioside antibodies (Abs) are the serological hallmark of the acute motor axonal form of the post-infectious paralysis, Guillain-Barré syndrome. Development of a disease model in mice has been impeded by the weak immunogenicity of gangliosides and the apparent resistance of GD1a-containing neural membranes to anti-GD1a antibody-mediated injury. Here we used mice with altered ganglioside biosynthesis to generate such a model at motor nerve terminals. First, we bypassed immunological tolerance by immunizing GD1a-deficient, ␤-1,4-N-acetylgalactosaminyl transferase knock-out mice with GD1a ganglioside-mimicking antigens from Campylobacter jejuni and generated high-titer anti-GD1a antisera and complement fixing monoclonal Abs (mAbs). Next, we exposed ex vivo nerve-muscle preparations from GD1a-overexpressing, GD3 synthase knock-out mice to the anti-GD1a mAbs in the presence of a source of complement and investigated morphological and electrophysiological damage. Dense antibody and complement deposits were observed only over presynaptic motor axons, accompanied by severe ultrastructural damage and electrophysiological blockade of motor nerve terminal function. Perisynaptic Schwann cells and postsynaptic membranes were unaffected. In contrast, normal mice were not only unresponsive to immunization with GD1a but also resistant to neural injury during anti-GD1a Ab exposure, demonstrating the central role of membrane antigen density in modulating both immune tolerance to GD1a and axonal susceptibility to anti-GD1a Abmediated injury. Identical paralyzing effects were observed when testing mouse and human anti-GD1a-positive sera. These data indicate that anti-GD1a Abs arise via molecular mimicry and are likely to be clinically relevant in injuring peripheral nerve axonal membranes containing sufficiently high levels of GD1a.

Vaccination of High-Risk Breast Cancer Patients with Carbohydrate Mimicking Peptides

“…Importantly, no inflammatory or demyelinating lesions were noted in nervous tissue, which generally has the highest tissue expression of gangliosides (data not shown). Normal mice appear to be resistant to neural injury during anti-GD1a antibody exposure, demonstrating the central role of membrane antigen density in modulating both immune tolerance to GD1a and axonal susceptibility to anti-GD1a antibody mediated injury [37]. In keeping with these general concepts our histopathology studies suggest that CMPs do not induce antibodies that mediate normal tissue destruction targeting gangliosides due to their low density of expression.…”

“…Our results indicate that a small increase in anti ssDNA is within normal variation, and is without clinical consequence in these mice. In pristane induced lupus ssDNA antibodies were found to be the first autoreactivity to appear (37), but appearance of these antibodies was followed within a couple of months by a diverse set of other pathological atuoreactivities. Thus, we hypothesize that the CMPs induced slightly increased levels of (natural) autoantibodies, but did not bring about overt autoimmunity.…”

“…And sections of liver, lung and primary tumor mass were prepared and stained with GS-I (Fig. 1) This animal model closely resembles human breast cancer and is a rigorous model of advanced spontaneous metastatic disease, which metastasizes efficiently to lung, liver, bone and brain after implanting into mammary fat pads (37)(38)(39)(40). Lung metastases were detected as early as day 14 after transplantation in all mice tested, whilst liver metastases were detected around day 28-35 after transplant, paralleling observations of others (23).. We observed enrichment in GS-I staining of tumor cells in sections of lung and liver compared to the primary tumor.…”

Neuromuscular synaptic transmission in aged ganglioside-deficient mice

“…Brains of compound null-mutants have increased GM3 expression Kawai et al, 2001). Our previous studies on pathophysiological effects of anti-ganglioside antibodies suggest that similar ganglioside accumulations also take place at NMJ motor nerve terminals of these mutants (Bullens et al, 2002;Goodfellow et al, 2005). The exact time course of these ganglioside accumulations in brain and NMJ are not known.…”

Guillain–Barré syndrome: a century of progress

“…Numerous investigators over several decades and several continents have attempted to determine whether these antibodies are pathogenetic and how they mediate damage. In summary, many collaborative efforts have demonstrated that anti-GM1 and anti-GQ1b antibodies bind to peripheral nerve and neuromuscular junctions 64,65 , and anti-GD1a antibodies bind to the nodes of Ranvier, paranodal myelin and neuromuscular junction 66,67,68 . Upon binding, the antibodies activate the complement cascade, resulting in formation of the membrane attack complex, disruption of sodium channel clusters at the node of Ranvier with disruption of nodal architecture 69 , and calcium influx and calpain-dependent neuronal and glial injury at the neuromuscular junction 70,71 .This injury can be ameliorated with complement inhibitors 72,73 .…”