EVIDENCE FOR THE PRESENCE OF A RECEPTOR FOR THE CYTOLETHAL DISTENDINGTOXIN (CLDT) OF CAMPYLOBACTER-JEJUNI ON CHO AND HELA-CELL MEMBRANES AND DEVELOPMENT OF A RECEPTOR-BASED ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR DETECTION OF CLDT

Using ligand blotting, it was found that partially purified cytolethal distending toxin prepared from an enterotoxigenic strain of Campyloba cter jejuni, bound to two peptides of molecular masses of approximatel y 59 kDa and 45 kDa and to a single peptide of 59 kDa in protein blots prepared from HeLa and CHO cell membranes, respectively. In contrast, labile toxin of Escherichia coli and cholera toxin bound to a single peptide of the same molecular mass (15 kDa) on protein blots prepared from both CHO and HeLa cell crude membranes resolved by gel electropho resis. This banding pattern was identical using SDS-solubilized membra ne, with or without heat treatment, but no band was obtained when redu ced (treatment with 2-mercaptoethanol) samples were used for the gel e lectrophoresis. The differences between receptors of cytolethal disten ding toxin and cholera toxin/labile toxin were exploited to develop a receptor-based enzyme-linked immunosorbent assay for detection of cyto lethal distending toxin which involved the consecutive addition of eit her solubilized CHO or HeLa membranes, antigen and antibody. This enzy me-linked immunosorbent assay consistently detected crude cytolethal d istending toxin diluted up to 16-fold. The receptor-based enzyme-linke d immunosorbent assay for detection of cytolethal distending toxin dev eloped in this study is a suitable alternative assay which can be perf ormed easily in laboratories with minimal facilities and, more importa ntly, the results are available within a few hours as compared to time s of up to 5 days in the conventional tissue culture detection of cyto lethal distending toxin.