title: Human intestinal epithelial cell-derived molecule(s) increase enterohemorrhagic Escherichia coli virulence.
abstract: To better understand the role of host cell-derived molecules on enterohemorrhagic Escherichia 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 Shiga 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 kDa, which suggests that the molecule(s) that increase EHEC virulence and attachment are protein-based.
authors.affiliation: Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.
authors.forename: Tarun
authors.initials: T
authors.lastname: Bansal
authors.forename: Dae N
authors.initials: DN
authors.lastname: Kim
authors.forename: Tim
authors.initials: T
authors.lastname: Slininger
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Wood
authors.forename: Arul
authors.initials: A
authors.lastname: Jayaraman
mesh_terms: D001422:Bacterial Adhesion; D002460:Cell Line; D017077:Culture Media, Conditioned; D054324:Enterohemorrhagic Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity*; D004847:Epithelial Cells / Q000737:chemistry* / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000096:biosynthesis; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D054884:Host-Pathogen Interactions; D006801:Humans; D007413:Intestinal Mucosa / Q000737:chemistry*; D039002:Prophages / Q000235:genetics; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D013997:Time Factors; D014764:Viral Proteins / Q000096:biosynthesis; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis
chemical_list: D017077:Culture Media, Conditioned; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D014764:Viral Proteins; D037521:Virulence Factors