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Updated: Oct 1, 2025
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Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
Published on: April 2, 2013
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Microbe Profile: Legionella pneumophila - a copycat eukaryote
Hubert Hilbi1, Carmen Buchrieser2
1Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006 Zürich, Switzerland.
Microbiology (Reading, England)
|March 1, 2022
Summary
Legionella pneumophila, a bacterium that infects humans and causes pneumonia, utilizes unique effector proteins acquired through horizontal gene transfer. Its co-evolution with protozoa grants it extensive host cell manipulation capabilities.
Area of Science:
- Microbiology
- Pathogen Biology
- Molecular Biology
Background:
- Legionella pneumophila is an environmental bacterium that causes severe pneumonia in humans.
- It infects aquatic protozoa, employing similar mechanisms for both protozoan and human cell invasion.
- This pathogen exhibits a unique co-evolutionary history with protozoan hosts.
Purpose of the Study:
- To investigate the unique characteristics of Legionella pneumophila's pathogenesis.
- To understand the role of effector proteins and horizontal gene transfer in L. pneumophila infection.
- To explore the mechanisms by which L. pneumophila manipulates host cells.
Main Methods:
- Analysis of L. pneumophila's effector repertoire.
- Investigation of type IV secretion system (T4SS) substrates.
- Comparative genomics to identify horizontally transferred genes.
- Functional assays to determine effector protein activities.
Main Results:
- L. pneumophila possesses the largest known repertoire of bacterial effector proteins.
- Many effectors are type IV-secreted proteins, likely acquired via interdomain horizontal gene transfer (HGT).
- The bacterium effectively subverts numerous eukaryotic signaling pathways and acquires eukaryotic enzyme activities.
Conclusions:
- L. pneumophila's pathogenic potential is significantly enhanced by its extensive effector arsenal and HGT-derived genes.
- The acquisition of eukaryotic enzyme activities allows for sophisticated host cell manipulation.
- Understanding these mechanisms provides insights into host-pathogen interactions and potential therapeutic targets.
Keywords:
antagonistic effectors (e.g. SidM/SidD)common targets (e.g. Rab1)functional redundancyhorizontal gene transfermetabolic changes (Warburg effect, sphingosine metabolism)metaeffectorsmost/all eukaryotic organelles/pathways are subvertedMore Related Videos
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