Role of lipid rafts and flagellin in invasion of colonic epithelial cells by Shiga-toxigenic Escherichia coli O113:H21

dc.contributor.authorRogers, T.
dc.contributor.authorThorpe, C.
dc.contributor.authorPaton, A.
dc.contributor.authorPaton, J.
dc.contributor.editorMcCormick, B.A.
dc.date.issued2012
dc.description.abstractShiga-toxigenic Escherichia coli (STEC) O113:H21 strains that lack the locus of enterocyte effacement (LEE) efficiently invade eukaryotic cells in vitro, unlike LEE-positive O157:H7 strains. We used a fliC deletion mutant of the O113:H21 STEC strain 98NK2 (98NK2ΔfliC) to show that invasion of colonic epithelial (HCT-8) cells is heavily dependent on production of flagellin, even though adherence to the cells was actually enhanced in the mutant. Flagellin binds and signals through Toll-like receptor 5 (TLR5), but there was no evidence that either TLR5, the adaptor protein myeloid differentiation primary response gene 88 (MyD88), or the serine kinase interleukin-1 receptor-associated kinase (IRAK) were required for invasion of HCT-8 cells by strain 98NK2, as judged by transfection, RNA knockdown, or inhibitor studies. However, pretreatment of cells with anti-asialo-GM1 significantly decreased 98NK2 invasion (by 40.8%), while neuraminidase treatment (which cleaves terminal sialic acid residues, thus converting GM1 into asialo-GM1) significantly increased invasion (by 70.7%). Pretreatment of HCT-8 cells with either the cholesterol-depleting agent methyl-β-cyclodextrin (MβCD) or the tyrosine kinase inhibitor genistein significantly decreased invasion by 98NK2, indicating a potential role for lipid rafts in the invasion mechanism. Confocal microscopy also showed invading 98NK2 colocalized with lipid raft markers caveolin-1 and GM1. Interestingly, anti-asialo-GM1, neuraminidase, MβCD, and genistein have similar effects on the vestigial level of STEC invasion seen for STEC strain 98NK2ΔfliC, indicating that lipid rafts mediate a common step in flagellin-dependent and flagellin-independent cellular invasion.
dc.description.statementofresponsibilityTrisha J. Rogers, Cheleste M. Thorpe, Adrienne W. Paton, and James C. Paton
dc.identifier.citationInfection and Immunity, 2012; 80(8):2858-2867
dc.identifier.doi10.1128/IAI.00336-12
dc.identifier.issn0019-9567
dc.identifier.issn1098-5522
dc.identifier.orcidPaton, J. [0000-0001-9807-5278]
dc.identifier.urihttp://hdl.handle.net/2440/76193
dc.language.isoen
dc.publisherAmer Soc Microbiology
dc.rightsCopyright © 2012, American Society for Microbiology. All Rights Reserved.
dc.source.urihttps://doi.org/10.1128/iai.00336-12
dc.subjectColon
dc.subjectCell Line, Tumor
dc.subjectMembrane Microdomains
dc.subjectEpithelial Cells
dc.subjectHumans
dc.subjectG(M1) Ganglioside
dc.subjectFlagellin
dc.subjectRNA, Small Interfering
dc.subjectGene Expression Regulation, Bacterial
dc.subjectRNA Interference
dc.subjectProtein Binding
dc.subjectToll-Like Receptor 5
dc.subjectShiga-Toxigenic Escherichia coli
dc.titleRole of lipid rafts and flagellin in invasion of colonic epithelial cells by Shiga-toxigenic Escherichia coli O113:H21
dc.typeJournal article
pubs.publication-statusPublished

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