Open AccessHuman intestinal epithelial cell‐derived molecule(s) increase enterohemorrhagic E scherichia coli virulence
Author(s) -
Bansal Tarun,
Kim Dae N.,
Slininger Tim,
Wood Thomas K.,
Jayaraman Arul
Publication year - 2012
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/1574-695x.12004
Subject(s) - virulence , biology , prophage , escherichia coli , microbiology and biotechnology , enterocyte , shiga toxin , gene expression , gene , stx2 , bacteriophage , genetics , biochemistry , small intestine
To better understand the role of host cell‐derived molecules on enterohemorrhagic E scherichia coli ( EHEC ) infection, we studied EHEC virulence gene expression when exposed to cell‐free spent (conditioned) medium ( CM ) from HCT ‐8 intestinal epithelial cells. Exposure to HCT ‐8 CM for 1 h and 3 h increased the expression of 32 of 41 EHEC locus of enterocyte effacement ( LEE ) virulence genes compared with fresh medium ( FM ). Expression of the S higa toxin 1 ( stx1B ) gene was up‐regulated at 1 h of exposure. Seventeen genes encoded by prophage 933W, including those for Stx2, were also up‐regulated at both time‐points. The increase in 933W prophage expression was mirrored by a 2.7‐fold increase in phage titers. Consistent with the increase in virulence gene expression, we observed a fivefold increase in EHEC attachment to epithelial cells when exposed to CM . The increase in EHEC attachment was abolished when CM was heated to 95 °C or treated with proteinase K to degrade the proteins. The host cell‐derived molecule(s) were larger than 3 kD a, which suggests that the molecule(s) that increase EHEC virulence and attachment are protein‐based.