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Related Experiment Video

Updated: May 8, 2026

Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells

Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells

Published on: August 5, 2016

Brucella modulates secretory trafficking via multiple type IV secretion effector proteins.

Sebenzile Myeni¹, Robert Child, Tony W Ng

¹Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.

|August 17, 2013

Summary

Brucella bacteria use a Type IV secretion system (T4SS) to inject effector proteins into host cells. These effectors, including BspA, BspB, and BspF, disrupt host protein secretion, aiding bacterial replication and persistence.

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Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions

Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions

Published on: October 13, 2015

Area of Science:

Microbiology
Cell Biology
Bacterial Pathogenesis

Background:

Brucella is an intracellular bacterium that forms a replicative vacuole (rBCV) by hijacking the host cell's secretory pathway.
The VirB Type IV secretion system (T4SS) is crucial for rBCV biogenesis and is believed to translocate effector proteins that manipulate host membrane trafficking.

Purpose of the Study:

To identify and characterize novel T4SS effector proteins translocated by Brucella.
To investigate the role of these effectors in modulating host cell functions and bacterial pathogenesis.

Main Methods:

In silico screening of Brucella genes for putative T4SS effector candidates based on specific criteria.
Utilized β-lactamase and CyaA reporter assays to confirm protein translocation into host cells.
Assessed the impact of identified effectors on host protein secretion and bacterial replication/persistence in vivo.

Main Results:

Identified eleven translocated proteins, with five (BspA, BspB, BspC, BspE, BspF) confirmed as VirB T4SS-dependent effectors.
Demonstrated that several effectors target secretory pathway compartments and inhibit host protein secretion.
Showed that BspA, BspB, and BspF are required for Brucella replication in macrophages and persistence in mice.

Conclusions:

Brucella employs multiple T4SS effector proteins to subvert host secretory trafficking.
These effectors, acting coordinately, play a significant role in promoting Brucella pathogenesis.
Targeting these effectors may offer novel strategies for controlling Brucella infections.