Effects of IgM Anti-Galnac-GD1a Monoclonal Antibody on Neuro | 46217

Journal of Neurology & Neurophysiology

ISSN - 2155-9562


Effects of IgM Anti-Galnac-GD1a Monoclonal Antibody on Neuromuscular Transmission and Calcium Channel Binding in the Rat Neuromuscular Junction

Sayako Hotta, Takumi Nagaoka, Yoshihiko Nakatani, Toshie Kambe, Kenji Abe, Yutaka Masuda, Iku Utsunomiya and Kyoji Taguchi

Guillain-Barré syndrome with antibodies against ganglioside N-acetylgalactosaminyl GD1a (GalNAc-GD1a) is
characterized by a rapid onset of predominantly distal pure motor neuropathy. However, the pathogenic role of anti-
GalNAc-GD1a antibody and calcium channels in neuromuscular junctions (NMJs) remains unclear. We investigated
the effects of IgM anti-GalNAc-GD1a monoclonal antibody (IgM anti-GalNAc-GD1a mAb) on spontaneous muscle
action potentials (SMAP) in a rat spinal cord–muscle co-culture system and the localization of IgM anti-GalNAc-
GD1a mAb and calcium channel binding in the rat hemi-diaphragm. Immunohistochemistry of the rat hemidiaphragm
showed that IgM anti-GalNAc-GD1a mAb binding overlapped with anti-neurofilament 200 antibody and α-
bungarotoxin staining, demonstrating that IgM anti-GalNAc-GD1a mAb was localized at the motor nerve terminal.
Moreover, IgM anti-GalNAc-GD1a mAb binding overlapped with anti-Cav2.1 antibody in the nerve terminal. We
suggest that the inhibitory effect of IgM anti-GalNAc-GD1a mAb on SMAP is related to the GalNAc-GD1a epitope on
P/Q-type calcium channels in motor nerve terminals at NMJs.