Campylobacter jejuni/coli - Host Intestinal Epithelial Cell Interaction

Abstract

Campylobacter jejuni/coli have been known to be major bacterial causes of human gastroenteritis worldwide for decades. Regarding its pathogenicity, little is known yet. A better understanding of the pathogenic mechanisms will provide important information, not only for generating molecular markers to differentiate pathogenic strains versus non-pathogenic ones; but also for developing rational strategies to prevent and control Campylobacter-caused disease. The objectives of this study were to characterize the pathogenic abilities of various C. jejuni/coli retail meat isolates, including their abilities to adhere to, invade into and transmigrate across human epithelial cells, to examine the role of NF-κB pathway in IL-8 secretion induced by Campylobacter, and to identify C. jejuni-specific adherence/invasion genes during host pathogen interaction. It was found that the adherence and invasiveness of total 43 Campylobacter retail meat isolates in human intestinal epithelial T84 cell model indicated that C. jejuni/coli present in retail meat were considerably diverse in their ability to adhere to and invade human epithelial cells. Meanwhile, eight putative virulence genes, determined by PCR, were shown to be widespread among the Campylobacter isolates. C. jejuni /coli-induced proinflammatory cytokine Interleukin (IL)-8 secretion in polarized human colonic epithelial cells T84 was examined, and the role of NF-κB pathway in Campylobacter-induced IL-8 secretion was determined. Data suggested that C. jejuni/coli induce basolateral-polarized secretion of IL-8 in human intestinal epithelial cells, and C. jejuni-induced IL-8 secretion is NF-κB-dependent. The effort to identify C. jejuni-specific adherence/invasion genes during host pathogen interaction by using restriction fragment differential display PCR (RFDD-PCR) has been made. As a result, it was not successful. However this study still provides useful information and experience on the application of this technique for prokaryotic gene expression analysis during host pathogen interaction, which remains an unexplored area. In summary, Campylobacter retail meat isolates exhibited wide diversity in cell culture model in the ability of adherence, invasion and transmigration. As the first line defense, intestinal epithelium activates NF-κB and secretes proinflammatory cytokine IL-8 in response to Campylobacter infection. Multiple virulence factors have roles in Campylobacter-intestinal epithelial cell interaction.