Human monoclonal immunoglobulin M antibodies to ganglioside GM(1) show diverse cross-reactivities with lipopolysaccharides of Campylobacter jejuni strains associated with Guillain-Barre syndrome

We examined the reactivity of a panel of anti-GM(1) immunoglobulin M monocl onal antibodies (MAbs) cloned from multifocal motor neuropathy patients wit h lipopolysaccharides (LPSs) of Campylobacter jejuni strains, including ser otype O:41 strains associated with Guillain-Barre syndrome. The MAbs reacte d with ganglioside GM(1) to different degrees, and these differences in fin e specificities for GM(!) were reflected in the different degrees of reacti vity with each of the C. jejuni LPSs tested. Antibodies could also be discr iminated by the varying patterns of inhibition by cholera toxin (a GM(1) li gand) in LPS binding studies. These results indicate that there is a substa ntial heterogeneity among C. jejuni O:41 strains in their expression of GM( 1)-like epitopes and among the fine specificities of different neuropathy-a ssociated anti-GM(1) antibodies.