Gene Regulation and Expression of Chemokines in Response to Bacterial Enterotoxins pp. 89-110
Authors: Jung Mogg Kim, Department of Microbiology, Hanyang University College of Medicine, Seoul, South Korea
Abstract: Bacterial enterotoxins are proteins released by specific bacterial organisms in the intestine and are chromosomally encoded exotoxins. The first host cells that enterotoxins interact with are intestinal epithelial cells, after which mucosal inflammatory signals are initiated. Characteristic features of inflammatory signals are the chemokine expression, leading to the migration of inflammatory cells into intestinal mucosa. Several microbial organisms produce the enterotoxin to create such an effect. These bacteria contain enterotoxigenic Bacteroides fragilis, Clostridium difficile and Staphylococcus aureus. This chapter will focus on the impact of bacterial enterotoxins on the gene regulation and expression of chemokines in intestinal epithelial cells. Enterotoxins produced from those bacteria up-regulate the expression of CXC and CC chemokines. The kinetics of each chemokine expression is different. For example, expression of the CXC chemokines, including IL-8 and growth-related oncogene (GRO)-, and the CC chemokines, including monocyte chemoattractant protein (MCP)-1, increases during the relatively early period after stimulation with C. difficile enterotoxin (toxin A) and B. fragilis enterotoxin. In contrast, expression of neutrophil activating protein-78 (ENA-78) is delayed. These findings suggest that the chemokines can contribute to the infiltration of inflammatory cells in the underlying infected intestinal mucosa.