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Updated: Jun 3, 2025
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An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
Published on: October 11, 2022
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Rickettsia parkeri forms extensive, stable contacts with the rough endoplasmic reticulum
Yamilex Acevedo-Sánchez1, Patrick J Woida1, Caroline Anderson1,2
1Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
The Journal of Cell Biology
|January 8, 2025
Summary
The bacterial pathogen Rickettsia parkeri forms extensive physical contacts with the host cell's endoplasmic reticulum (ER). These interactions are mediated by ER-specific tethers, suggesting a novel host-pathogen communication.
Area of Science:
- Microbiology
- Cell Biology
- Pathogen-Host Interactions
Background:
- Bacterial pathogens invading host cells often reside in the cytosol.
- Previous studies focused on plasma membrane interactions and immune evasion by these pathogens.
- The interaction of cytosolic bacteria with host organelles remained largely unexplored.
Purpose of the Study:
- To investigate whether the obligate intracellular pathogen Rickettsia parkeri interacts with host cell organelles.
- Specifically, to determine if R. parkeri interacts with the endoplasmic reticulum (ER).
Main Methods:
- Live-cell microscopy
- Transmission electron microscopy (TEM)
- Focused-ion-beam scanning electron microscopy (FIB-SEM)
- Depletion of ER-specific tethers (VAPA and VAPB)
Main Results:
- Rickettsia parkeri forms extensive contacts with the rough endoplasmic reticulum.
- These contacts are approximately 55 nm apart and cover over half the bacterial surface.
- Depletion of VAPA and VAPB significantly reduced these Rickettsia-ER contacts.
- VAPA and VAPB were observed localized around intracellular R. parkeri.
Conclusions:
- Rickettsia parkeri establishes unique physical contacts with the host endoplasmic reticulum.
- These interkingdom ER contacts are mediated by host tethers VAPA and VAPB.
- This interaction mimics characteristics of host membrane contact sites, revealing a novel aspect of pathogen-host cell biology.
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