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Updated: Jul 11, 2026
07:15
Invasion of Human Cells by a Bacterial Pathogen
Published on: March 21, 2011
Autophagy defends cells against invading group A Streptococcus
Ichiro Nakagawa1, Atsuo Amano, Noboru Mizushima
1Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita-Osaka 565-0871, Japan. ichiro@dent.osaka-u.ac.jp
Science (New York, N.Y.)
|November 6, 2004
Summary
The cell
Area of Science:
- Cellular Biology
- Immunology
- Microbiology
Background:
- Group A Streptococcus (GAS) is a pathogenic bacterium.
- Intracellular pathogens can evade host defenses.
- Autophagy is a cellular process for degrading damaged components.
Purpose of the Study:
- To investigate the role of autophagy in eliminating intracellular GAS.
- To determine if autophagy acts as an innate defense mechanism against GAS.
Main Methods:
- Utilized nonphagocytic cells to study intracellular GAS.
- Observed GAS behavior in wild-type and autophagy-deficient (Atg5-/-) cells.
- Analyzed the engulfment of GAS by autophagosome-like compartments and lysosomal fusion.
Main Results:
- Autophagic machinery effectively eliminated GAS within nonphagocytic cells.
- GAS escaping into the cytoplasm were enclosed in autophagosome-like compartments.
- GAS survived and multiplied in autophagy-deficient cells, leading to their release.
Conclusions:
- Autophagy serves as a crucial innate defense system against intracellular GAS.
- The autophagic pathway targets and eliminates invading GAS pathogens.
- Impaired autophagy compromises the host's ability to control GAS infection.
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