[ODP-104] Analysis on the host receptor of enterotoxigenic Escherichia coli colonization factor CS6
Enterotoxigenic E. coli (ETEC) is the leading cause of diarrhoea among children in underdeveloped nations and travellers’ diarrhoea. There are more than 25 identified colonization factors (CF) for ETEC, and CS6 is one of the predominant CF types and prevalent in developing countries. However, the specific receptors of CS6 are still unidentified. We previously observed that CS6 showed high binding affinity to the INT407 cell line but not to Caco-2. Therefore, to identify the CS6 receptor, we conducted differential gene expression microarray analysis between INT407 and Caco-2. As a result, we found 17 cell membrane-associated and extracellular matrix protein genes showed more than five times higher expression in INT407 compared to Caco-2. After confirming the results by subsequent RT-PCR, we picked up MUC1 and MUC16 as possible CS6 receptor candidates for two reasons; 1) CS6 binds to crude mucin extracted from rabbit small intestine as we already reported, 2) we showed that galactose, glucose and mannose inhibited CS6 binding to INT407 synergistically, suggesting that CS6 receptor is not glycolipid but rather a glycoprotein. Construction of MUC1 and MUC16 knockdown INT407 cell line by transforming shRNA plasmids via electroporation is ongoing in order to examine whether or not CS6 binding to these knockdown cells is reduced.