title: Bruton's tyrosine kinase regulates Shigella flexneri dissemination in HT-29 intestinal cells.
abstract: Shigella flexneri is a Gram-negative intracellular pathogen that infects the intestinal epithelium and utilizes actin-based motility to spread from cell to cell. S. flexneri actin-based motility has been characterized in various cell lines, but studies in intestinal cells are limited. Here we characterized S. flexneri actin-based motility in HT-29 intestinal cells. In agreement with studies conducted in various cell lines, we showed that S. flexneri relies on neural Wiskott-Aldrich Syndrome protein (N-WASP) in HT-29 cells. We tested the potential role of various tyrosine kinases involved in N-WASP activation and uncovered a previously unappreciated role for Bruton's tyrosine kinase (Btk) in actin tail formation in intestinal cells. We showed that Btk depletion led to a decrease in N-WASP phosphorylation which affected N-WASP recruitment to the bacterial surface, decreased the number of bacteria displaying actin-based motility, and ultimately affected the efficiency of spread from cell to cell. Finally, we showed that the levels of N-WASP phosphorylation and Btk expression were increased in response to infection, which suggests that S. flexneri infection not only triggers the production of proinflammatory factors as previously described but also manipulates cellular processes required for dissemination in intestinal cells.
authors.affiliation: Department of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Dragoi
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Talman
authors.forename: Hervé
authors.initials: H
authors.lastname: Agaisse
mesh_terms: D000199:Actins / Q000378:metabolism; D000077329:Agammaglobulinaemia Tyrosine Kinase; D045744:Cell Line, Tumor; D003600:Cytosol / Q000378:metabolism / Q000382:microbiology; D004405:Dysentery, Bacillary / Q000201:enzymology / Q000378:metabolism* / Q000382:microbiology; D019073:HT29 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology / Q000378:metabolism* / Q000382:microbiology*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012763:Shigella flexneri / Q000378:metabolism* / Q000472:pathogenicity; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism
chemical_list: D000199:Actins; C495771:WASL protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human