Cross-reactive epitopes present in campylobacter jejuni serotypes isolated from enteritis patients.

Campylobacter jejuni (C. jejuni) infection frequently triggers autoimmune-mediated neuropathies, especially the Guillain-Barre syndrome (GBS). The molecular mimicry between the core oligosaccharides of bacterial lipopolysaccharides (LPSs) and the human gangliosides presumably results in the production of anti-neural cross-reactive antibodies which are likely to be a contributory factor in the induction and pathogenesis of GBS. The aim of our study was to determine the presence of cross-reactive epitopes in C. jejuni LPSs isolated from enteritis patients and to determine their antigen reactivity. For that purpose we collected stool specimens from 21 patients with enteritis and without neurological symptoms. Seven different serotypes of C. jejuni (0:27; 0:6/0:7; 0:38; 0:3; 0:1/0:44; 0:19; 0:37) were detected using the Penner system. Unexpectedly, one serotype from this group was detected as 0:19, a serotype rarely isolated from enteritis patient and in close association with GBS. Binding studies using cholera toxin-B subunit and peanut agglutinin, showed the presence of ganglioside-like epitopes in C. jejuni strains 0:37, 0:19 and 0:27. Reactivity with sera from patient with GBS, with confirmed previous exposure to C. jejuni and with high a titre of anti-ganglioside antibodies, showed that the same three LPSs from C. jejuni serotypes 0:37, 0:19 and 0:27 bear cross-reactive epitopes in their LPSs structures. Our results confirm the results from previous studies that LPSs from certain C. jejuni serotypes bear cross-reactive ganglioside-like epitopes which might be involved in the induction of GBS after C. jejuni infection.