Staphylococcus aureus subvert autophagy for induction of caspase-independent host cell death

J Biol Chem. 2007 Jan 26;282(4):2695-706. doi: 10.1074/jbc.M609784200. Epub 2006 Nov 29.

Abstract

Staphylococcus aureus is a common bacterial etiology of serious infectious diseases. S. aureus can invade various types of non-professional phagocytes to produce host cell death. We show here that shortly after invasion of HeLa cells S. aureus transit to autophagosomes was characterized by double membranes and co-localization with LC3. S. aureus were not able to replicate and produce cell death in autophagy-deficient atg5-/- mouse embryonic fibroblasts. S. aureus-containing autophagosomes do not acidify nor do they acquire lysosome-associated membrane protein-2, indicating that S. aureus inhibits autophagosome maturation and fusion with lysosomes. Eventually, S. aureus escape from autophagosomes into the cytoplasm, which results in caspase-independent host cell death. S. aureus strains deficient for agr, a global regulator of S. aureus virulence, were not targeted by autophagy and did not produce host-cell death. Autophagy induction by rapamycin restored both replication and cytotoxicity of agr-deficient S. aureus strains, indicating that an agr-regulated factor(s) is required for autophagy-mediated cytotoxicity. The results of this study suggest that rapid induction of autophagy is essential for S. aureus replication, escape into the cytoplasm, and host cell killing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy*
  • Autophagy-Related Protein 5
  • Bacterial Proteins / metabolism
  • Caspases / metabolism*
  • HeLa Cells
  • Humans
  • Mice
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Models, Biological
  • Staphylococcal Infections* / metabolism
  • Staphylococcal Infections* / pathology
  • Staphylococcus aureus*
  • Trans-Activators / metabolism

Substances

  • ATG5 protein, human
  • Agr protein, Staphylococcus aureus
  • Atg5 protein, mouse
  • Autophagy-Related Protein 5
  • Bacterial Proteins
  • Microtubule-Associated Proteins
  • Trans-Activators
  • Caspases