Immunological properties and ganglioside recognitions by Campylobacter jejuni-enterotoxin and cholera toxin

The immunological properties of Campylobacter jejuni enterotoxin (CJT) and cholera toxin (CT) were compared by enzyme-linked immunosorbent assay (ELISA) and Western blotting analysis with antiserum against each toxin. Antibody against CJT recognized the 68, 54 and 43 kDa polypeptides of CJT and the 11 kDa subunit of CT, whereas antibody against CT recognized the 68 and 54 kDa polypeptides of CJT and 11 kDa subunit of CT. The immunological reactions between the heterogeneous combinations of toxins and the antibodies were weaker than those between the homogenous systems. Thus, different antigenicity was found in CJT and CT at the subunit level, although they possessed cross-reactive epitope(s). The binding of CJT and CT to gangliosides was also examined. CJT and CT bound to GM1 ganglioside preferentially than to other ganglioside species. However, CJT did not bind to GD1b in spite of the fact that CT preferred GD1b. This suggests that both toxins recognize different receptors on the surface of the target cell. This study is the first demonstration of the different properties between CJT and CT in immunological character and ganglioside recognition.