Adhesion to HeLa cells of Campylobacter jejuni and C. coli outer membrane components

Adhesion of Campylobacter jejuni and C. coli to epithelial cells is thought to be a decisive step in enteritis. In this work, we tried to determine which bacterial components are responsible for this phenomenon. Outer membrane (OM) extracts were prepared from strains of C. jejuni (3 strains) and C. coli (2 strains). These strains had been isolated from stools of febrile patients with diarrhoea and were able to adhere to HeLa cells in culture. After incubation of bacterial OM extracts with HeLa cells in culture, bacterial adherent material was recovered, subjected to electrophoresis and immunoblotted. Bacterial adherent antigens were revealed by a rabbit antiserum raised against whole bacterial cells. Antigenic fractions, ranging from 26 to 30 kDa, were found to preferentially bind to HeLa cells (cell-binding fractions; CBF). These antigens were proteins and were distinct from flagellin and lipopolysaccharide. Bacteria incubated with a rabbit antiserum raised against homologous CBF, were unable to bind to HeLa cells. Moreover, the inhibitory effect decreased when the antiserum was diluted. Under the same conditions, a rabbit antiserum raised against a non-adherent OM fraction of 92 kDa did not prevent bacteria from binding to HeLa cells.