Candida albicans phospholipomannan promotes survival of phagocytosed yeasts through modulation of bad phosphorylation and macrophage apoptosis

J Biol Chem. 2003 Apr 11;278(15):13086-93. doi: 10.1074/jbc.M210680200. Epub 2003 Jan 27.

Abstract

The surface of the pathogenic yeast Candida albicans is coated with phospholipomannan (PLM), a phylogenetically unique glycolipid composed of beta-1,2-oligomannosides and phytoceramide. This study compared the specific contribution of PLM to the modulation of signaling pathways linked to the survival of C. albicans in macrophages in contrast to Saccharomyces cerevisiae. C. albicans endocytosis by J774 and disregulation of the ERK1/2 signal transduction pathway was associated downstream with a reduction in Bad Ser-112 phosphorylation and disappearance of free Bcl-2. This suggested an apoptotic effect, which was confirmed by staining of phosphatidylserine in the macrophage outer membrane. The addition of PLM to macrophages incubated with S. cerevisiae mimicked each of the disregulation steps observed with C. albicans and promoted the survival of S. cerevisiae. Externalization of membranous phosphatidylserine, loss of mitochondrial integrity, and DNA fragmentation induced by PLM showed that this molecule promoted yeast survival by inducing host cell death. These findings suggest strongly that PLM is a virulence attribute of C. albicans and that elucidation of the relationship between structure and apoptotic activity is an innovative field of research.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Candida albicans / physiology*
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cell Membrane / physiology
  • Cell Survival / physiology*
  • Endocytosis / physiology
  • Female
  • Glycolipids / pharmacology*
  • Macrophages
  • Mice
  • Mice, Inbred BALB C
  • Phagocytosis / physiology*
  • Phosphorylation
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Saccharomyces cerevisiae / physiology*
  • Signal Transduction
  • bcl-Associated Death Protein

Substances

  • Bad protein, mouse
  • Carrier Proteins
  • Glycolipids
  • Proto-Oncogene Proteins c-bcl-2
  • bcl-Associated Death Protein
  • phospholipomannan