title: TLR4-mediated expulsion of bacteria from infected bladder epithelial cells.
abstract: Uropathogenic Escherichia coli invade bladder epithelial cells (BECs) by direct entry into specialized cAMP regulated exocytic compartments. Remarkably, a significant number of these intracellular bacteria are subsequently expelled in a nonlytic and piecemeal fashion by infected BECs. Here, we report that expulsion of intracellular E. coli by infected BECs is initiated by the pattern recognition receptor, Toll-like receptor (TLR)4, after activation by LPS. Also, we reveal that caveolin-1, Rab27b, PKA, and MyRIP are components of the exocytic compartment, and that they form a complex involved in the exocytosis of bacteria. This capacity of TLR4 to mediate the expulsion of intracellular bacteria from infected cells represents a previously unrecognized function for this innate immune receptor.
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Jeongmin
authors.initials: J
authors.lastname: Song
authors.forename: Brian L
authors.initials: BL
authors.lastname: Bishop
authors.forename: Guojie
authors.initials: G
authors.lastname: Li
authors.forename: Richard
authors.initials: R
authors.lastname: Grady
authors.forename: Ann
authors.initials: A
authors.lastname: Stapleton
authors.forename: Soman N
authors.initials: SN
authors.lastname: Abraham
mesh_terms: D051242:Caveolin 1 / Q000378:metabolism; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology*; D005089:Exocytosis; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000276:immunology* / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000378:metabolism
chemical_list: D051242:Caveolin 1; D008070:Lipopolysaccharides; C501262:MYRIP protein, human; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D033921:Vesicular Transport Proteins; D000242:Cyclic AMP; C512960:Rab27B protein, human; D020691:rab GTP-Binding Proteins
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