Listeria monocytogenes infection induces prosurvival metabolic signaling in macrophages

Infect Immun. 2011 Apr;79(4):1526-35. doi: 10.1128/IAI.01195-10. Epub 2011 Jan 24.

Abstract

Host cells use metabolic signaling through the LXRα nuclear receptor to defend against Listeria monocytogenes infection. 25-Hydroxycholesterol is a natural ligand of LXRs that is produced by the enzyme cholesterol 25-hydroxylase (CH25H). We found that expression of Ch25h is upregulated following L. monocytogenes infection in a beta interferon (IFN-β)-dependent fashion. Moreover, increased Ch25h expression promotes survival of L. monocytogenes-infected cells and increases sensitivity of the host to infection. We determined that expression of Cd5l, a prosurvival gene, is controlled by CH25H. In addition, we found that CD5L inhibits activation of caspase-1, promoting survival of infected macrophages. Our results reveal a mechanism by which an intracellular pathogen can prolong survival of infected cells, thus providing itself with a protected environment in which to replicate.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins / biosynthesis
  • Blotting, Western
  • Female
  • Gene Expression
  • Gene Expression Regulation / genetics
  • In Situ Nick-End Labeling
  • Listeria monocytogenes / physiology*
  • Listeriosis / immunology
  • Listeriosis / metabolism*
  • Macrophages / metabolism*
  • Macrophages / microbiology*
  • Mice
  • Mice, Inbred C57BL
  • Receptors, Immunologic / biosynthesis
  • Receptors, Scavenger
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology*
  • Steroid Hydroxylases / biosynthesis*
  • Up-Regulation

Substances

  • Apoptosis Regulatory Proteins
  • Cd5l protein, mouse
  • Receptors, Immunologic
  • Receptors, Scavenger
  • Steroid Hydroxylases
  • cholesterol 25-hydroxylase