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Autophagy defends cells against invading group A Streptococcus
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| Science, 306(5698), 1037-1040, 2004 |
| Yoshimori Laboratory, Division of Cytogenetics |
Autophagy defenses cells against invading group A Streptococcus.
Nakagawa I, Amano A, Mizushima N, Yamamoto A, Yamaguchi H, Kamimoto T, Nara A, Funao J, Nakata M, Tsuda K, Hamada S, Yoshimori T
Science, 2004.
Autophagy is a major degradation/recycling system inside cells. It contributes in turnover of cellular constituents and removal of excess organelles. Under starvation condition, cells provide nutrients essential for survival by autophagic self degradation. Here we found that the autophagic machinery could effectively eliminate the pathogenic group A Streptococcus (GAS) within non-phagocytic cells. After escaping from endosomes into the cytoplasm, GAS became enveloped by autophagosome-like compartments, and were killed upon fusion of these compartments with lysosomes. In autophagy deficient Atg5-/- cells, GAS survived, multiplied, and were released from the cells. Thus, the autophagic machinery can act as an innate defence system against invading pathogens.
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Upper left: large structures in which an autophagosome marker LC3 (green) localized trapped Group A Streptococcus (magenta) that had invaded into cells. Lower left: An electron micrograph showing Mega-autophagosome sequestering a lot of the bacteria. Engulfed bacteria and the cytosol began to be degraded by fusion between the compartment and lysosomes. Bar: 1μm. Right: Schematic model for fate of Group A Streptococcus after invasion into cells.
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Entrez PubMed |
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