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Updated: May 19, 2026
13:54
Tractable Mammalian Cell Infections with Protozoan-primed Bacteria
Published on: April 2, 2013
Bacteria and protozoa differentially modulate the expression of Rab proteins
Elsa Seixas1, José S Ramalho, Luís J Mota
1CEDOC, Faculdade de Ciências Médicas (FCM), Universidade Nova de Lisboa, Lisboa, Portugal.
Plos One
|August 23, 2012
Summary
Pathogens like Plasmodium berghei and bacteria alter Rab GTPase gene expression to evade immune cells. Modulating Rab14 and Rab9a levels impacts pathogen uptake, suggesting a novel immune evasion strategy.
Area of Science:
- Immunology
- Cell Biology
- Microbiology
Background:
- Phagocytic cells are crucial for innate immunity, engulfing microbes via phagosomes.
- Rab GTPases regulate vesicular trafficking in the endocytic pathway, essential for phagosome maturation.
- Intracellular pathogens may manipulate host immune responses by targeting Rab proteins.
Purpose of the Study:
- To investigate if pathogens modulate Rab GTPase gene expression to subvert host immunity.
- To compare Rab GTPase expression changes induced by Plasmodium berghei versus Escherichia coli and Salmonella enterica in macrophages.
- To determine the role of specific Rab proteins (Rab14, Rab9a) in phagocytosis of these microbes.
Main Methods:
- Comparative analysis of 23 Rab GTPase expression levels in mouse macrophages post-infection.
- Gene silencing and overexpression experiments for Rab14 and Rab9a.
- Quantification of phagocytosis rates for P. berghei, E. coli, and S. enterica.
Main Results:
- P. berghei induced distinct Rab gene expression changes compared to E. coli and S. enterica.
- Silencing Rab14 increased P. berghei phagocytosis; overexpression decreased it, suggesting parasite manipulation.
- Silencing Rab9a increased bacterial phagocytosis; overexpression decreased it, indicating a role in bacterial evasion.
Conclusions:
- Pathogens modulate Rab GTPase gene expression as a mechanism for immune evasion.
- Rab protein expression levels are critical for the success of microbial infections.
- This study reveals a novel host-pathogen interaction involving Rab gene regulation.
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