Listeria hijacks host mitophagy through a novel mitophagy receptor to evade killing

Nat Immunol. 2019 Apr;20(4):433-446. doi: 10.1038/s41590-019-0324-2. Epub 2019 Feb 25.

Abstract

Cells use mitophagy to remove damaged or unwanted mitochondria to maintain homeostasis. Here we report that the intracellular bacterial pathogen Listeria monocytogenes exploits host mitophagy to evade killing. We found that L. monocytogenes induced mitophagy in macrophages through the virulence factor listeriolysin O (LLO). We discovered that NLRX1, the only Nod-like receptor (NLR) family member with a mitochondrial targeting sequence, contains an LC3-interacting region (LIR) and directly associated with LC3 through the LIR. NLRX1 and its LIR motif were essential for L. monocytogenes-induced mitophagy. NLRX1 deficiency and use of a mitophagy inhibitor both increased mitochondrial production of reactive oxygen species and thereby suppressed the survival of L. monocytogenes. Mechanistically, L. monocytogenes and LLO induced oligomerization of NLRX1 to promote binding of its LIR motif to LC3 for induction of mitophagy. Our study identifies NLRX1 as a novel mitophagy receptor and discovers a previously unappreciated strategy used by pathogens to hijack a host cell homeostasis system for their survival.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy
  • Bacterial Toxins / metabolism
  • Cell Line
  • Female
  • Heat-Shock Proteins / metabolism
  • Hemolysin Proteins / metabolism
  • Humans
  • Listeria monocytogenes / pathogenicity
  • Listeria monocytogenes / physiology*
  • Listeriosis / metabolism
  • Listeriosis / microbiology
  • Macrophages / microbiology
  • Macrophages / ultrastructure
  • Male
  • Mice
  • Mice, Knockout
  • Microbial Viability
  • Mitochondria / metabolism
  • Mitochondria / ultrastructure
  • Mitochondrial Proteins / chemistry
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism
  • Mitochondrial Proteins / physiology*
  • Mitophagy*
  • Protein Domains
  • Reactive Oxygen Species / metabolism
  • Virulence Factors / metabolism

Substances

  • Bacterial Toxins
  • Heat-Shock Proteins
  • Hemolysin Proteins
  • Mitochondrial Proteins
  • NLRX1 protein, mouse
  • Reactive Oxygen Species
  • Virulence Factors
  • hlyA protein, Listeria monocytogenes