Cell association and invasion of Caco-2 cells by Campylobacter jejuni.
Adherence and invasion studies were conducted in monolayers of Caco-2 cells. Three-day-old monolayers were inoculated with Campylobacter jejuni 81-176 at a bacterium/cell ratio of 1,000:1. Saturation studies demonstrated time- and dose-dependent saturation curves for C. jejuni cell association and invasion into Caco-2 cells. Electron microscopy revealed intracellular C. jejuni located within membrane-bound vacuoles. Cell association and invasion were inhibited by 0.3 and 0.5 M concentrations of various sugars, including D-glucose, D-mannose, and D-fucose. However, there was no inhibition with the corresponding L-sugars, indicating physiological specificity. The inhibition of cell association with phloridzin was less pronounced. There was no inhibition of bacterial entry with monodansylcadaverine or g-strophanthin, indicating that it was unlikely that coated-pit formation is important in the invasion of C. jejuni into Caco-2 cells. Furthermore, there was no inhibition with cytochalasin D, vincristine, or vinblastine. Inhibition of cell association was demonstrated at 4 degrees C. Significantly decreased cell association and invasion were seen in potassium-depleted cells. Treatment of cells with bromelain also caused reduction in the number of C. jejuni binding to cells. A nonmotile aflagellate variant of C. jejuni also showed reduced invasion. The results of this study are consistent with energy-dependent invasion mechanisms. The results do not support an endocytic method of invasion for C. jejuni into Caco-2 cells.
Russell
R G
RG
Department of Pathology, School of Medicine, University of Maryland at Baltimore 21201.
Blake
D C
DC
D016123:Campylobacter jejuni / Q000472:pathogenicity*; D002701:Chloramphenicol / Q000494:pharmacology; D003106:Colon / Q000382:microbiology*; D006801:Humans; D010695:Phlorhizin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014750:Vincristine / Q000494:pharmacology
D014750:Vincristine; D002701:Chloramphenicol; D010695:Phlorhizin