Invasin of Yersinia pseudotuberculosis binds to beta1-integrins on host cells and triggers internalization of the bacterium. To elucidate the mechanism behind the beta1-integrin-mediated internalization of Yersinia, a beta1-integrin-deficient cell line, GD25, transfected with wild-type beta1A, beta1B or different mutants of the beta1A subunit was used. Both beta1A and beta1B bound to invasin-expressing bacteria, but only beta1A was able to mediate internalization of the bacteria. The cytoplasmic region of beta1A, differing from beta1B, contains two NPXY motifs surrounding a double threonine site. Exchanging the tyrosines of the two NPXYs to phenylalanines did not inhibit the uptake, whereas a marked reduction was seen when the first tyrosine (Y783) was exchanged to alanine. A similar reduction was seen when the two nearby threonines (TT788-9) were exchanged with alanines. It was also noted that cells affected in bacterial internalization exhibited reduced spreading capability when seeded onto invasin, suggesting a correlation between the internalization of invasin-expressing bacteria and invasin-induced spreading. Likewise, integrins defective in forming peripheral focal complex structures was unable to mediate uptake of invasin-expressing bacteria.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1242/jcs.115.13.2669 | DOI Listing |
J Control Release
October 2017
VIB-UGent Center for Medical Biotechnology, VIB, Technologiepark, 927, Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, Ghent, Belgium. Electronic address:
We describe a novel live oral vaccine type. Conceptually, this vaccine is based on a non-lytic, recombinant filamentous bacteriophage that displays an antigen of interest. To provide proof of concept we used the amino-terminal part of a conserved influenza A virus epitope, i.
View Article and Find Full Text PDFMicrobes Infect
May 2015
Department of Clinical Microbiology, Umeå University, Umeå, Sweden; Laboratory for Molecular Infection Medicine, Sweden (MIMS) and Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden. Electronic address:
Yersinia pseudotuberculosis adhesive protein invasin is crucial for the bacteria to cross the intestine epithelium by binding to β1 integrins on M-cells and gaining access to the underlying tissues. After the crossing invasin can bind to β1 integrins on other cell surfaces, however effector proteins delivered by the type III secretion system Y. pseudotuberculosis efficiently inhibit potential immune responses induced by this interaction.
View Article and Find Full Text PDFJ Immunol
October 2006
Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Live attenuated Shigella vaccines elicit protective immune responses, but involve a potential risk of inducing a strong inflammatory reaction. The bacterial invasiveness that is crucial for Ag delivery causes inflammatory destruction of infected epithelial cells and proinflammatory cell death of infected macrophages. In this study, the noninvasive Shigella mutant DeltaipaB was equipped with Yersinia invasin protein, which has been shown to mediate bacterial invasion and targeting to M cells located in follicle-associated epithelium.
View Article and Find Full Text PDFCell Microbiol
September 2004
Laboratory of Lympho-epithelial Interactions, Department of Cell Biology and Infection, Institut Pasteur, 28 Rue du Docteur Roux, 75015 Paris, France.
Beta1 integrins are anchored on the basal membrane of enterocytes, but little is known about their localization in M cells, which are the main entry route into the intestinal mucosa for many bacterial pathogens. In particular, it has been suggested that adhesion of enteropathogenic Yersinia to M cells is mediated by interaction of the bacterial protein invasin and apical beta1 integrins. Using a novel in vitro model of M cells, we demonstrate an augmented apical and basolateral targeting of beta1 integrins in M cells associated with increased total alpha chain synthesis.
View Article and Find Full Text PDFInt J Med Microbiol
April 2003
Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Universitätsklinikum Tübingen, Elfriede-Aulhorn-Str. 6, D-72076 Tübingen, Germany.
The chromosomally encoded inv gene product is an outer membrane protein that is functionally expressed in the enteropathogenic Yersinia species Yersinia enterocolitica and Yersinia pseudotuberculosis. Invasin protein is a high-affinity ligand for beta1 integrins and especially important in the early phase of intestinal infection for efficient translocation through the M cells located in the follicle-associated epithelium overlying the Peyer's patches. In addition to bacterial internalization, Yersinia invasin mediates proinflammatory epithelial cell reactions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!