Human Macrophages Infected with a High Burden of ESAT-6-Expressing M. tuberculosis Undergo Caspase-1- and Cathepsin B-Independent Necrosis
2011

How Mycobacterium tuberculosis Kills Macrophages

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Author Information

Author(s): Amanda Welin, Daniel Eklund, Olle Stendahl, Maria Lerm

Primary Institution: Linköping University, Sweden

Hypothesis

Can Mycobacterium tuberculosis induce cell death in macrophages through inflammasome-linked pathways?

Conclusion

Infection with virulent Mycobacterium tuberculosis leads to macrophage necrosis that is dependent on the bacterial protein ESAT-6 and is independent of caspase-1 and cathepsin B.

Supporting Evidence

  • Infection with H37Rv at MOI 10 caused extensive DNA fragmentation and loss of mitochondrial integrity.
  • Cell death was independent of caspase-1 and cathepsin B, indicating a necrotic process.
  • ESAT-6 was identified as a key factor in inducing necrosis in macrophages.

Takeaway

When the bacteria that cause tuberculosis infect immune cells, they can make those cells die in a way that helps the bacteria spread, and this process depends on a specific protein from the bacteria.

Methodology

Human monocyte-derived macrophages were infected with virulent Mycobacterium tuberculosis at different multiplicities of infection (MOI) and analyzed for cell death characteristics.

Limitations

The study primarily focuses on a specific strain of Mycobacterium tuberculosis and may not generalize to all strains or conditions.

Participant Demographics

Human monocyte-derived macrophages from healthy blood donors.

Statistical Information

P-Value

p<0.05

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0020302

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