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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
14:05

Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes

Published on: September 19, 2013

A PEST-like sequence in listeriolysin O essential for Listeria monocytogenes pathogenicity

A L Decatur1, D A Portnoy

  • 1Department of Molecular and Cell Biology, Division of Infectious Diseases, School of Public Health, University of California, Berkeley, CA 94720, USA.

Science (New York, N.Y.)
|November 4, 2000
PubMed

Insights

A PEST-like sequence in Listeria monocytogenes listeriolysin O (LLO) is crucial for pathogen virulence. This sequence targets LLO for degradation, preventing host cell damage and enabling intracellular survival.

Area of Science:

  • Microbiology
  • Cell Biology
  • Pathogen-Host Interactions

Background:

  • Intracellular pathogens require a protected niche for survival and replication within host cells.
  • Listeria monocytogenes utilizes the pore-forming protein listeriolysin O (LLO) during its infection cycle.

Purpose of the Study:

  • To investigate the role of a PEST-like sequence in LLO function, virulence, and intracellular compartmentalization.
  • To determine the impact of this sequence on LLO's interaction with host cells.

Main Methods:

  • Site-directed mutagenesis to create LLO mutants lacking the PEST-like sequence.
  • Analysis of bacterial entry into host cells and subsequent intracellular fate.
  • Assessment of host cell viability and integrity.
  • Functional transfer of the PEST-like sequence to another cytolysin, perfringolysin O.

Main Results:

  • LLO mutants lacking the PEST-like sequence entered the host cytosol but caused host cell permeabilization and death.
  • LLO lacking the PEST-like sequence accumulated in the host cytosol, indicating it targets LLO for degradation.
  • Transferring the PEST-like sequence to perfringolysin O rendered it non-toxic and promoted intracellular growth.

Conclusions:

  • The PEST-like sequence in LLO is essential for Listeria monocytogenes virulence and proper intracellular compartmentalization.
  • This sequence mediates LLO degradation, preventing premature host cell lysis and facilitating pathogen survival.
  • The PEST-like sequence can be functionally transferred to other cytolysins to modulate their toxicity and promote intracellular growth.

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