Interferon-mediated reprogramming of membrane cholesterol to evade bacterial toxins

Nat Immunol. 2020 Jul;21(7):746-755. doi: 10.1038/s41590-020-0695-4. Epub 2020 Jun 8.

Abstract

Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, the mechanisms by which these cells evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages and neutrophils. We traced IFN-mediated resistance to CDCs to the rapid modulation of a specific pool of cholesterol in the plasma membrane of macrophages without changes to total cholesterol levels. Resistance to CDC-induced pore formation requires the production of the oxysterol 25-hydroxycholesterol (25HC), inhibition of cholesterol synthesis and redistribution of cholesterol to an esterified cholesterol pool. Accordingly, blocking the ability of IFN to reprogram cholesterol metabolism abrogates cellular protection and renders mice more susceptible to CDC-induced tissue damage. These studies illuminate targeted regulation of membrane cholesterol content as a host defense strategy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteria / immunology
  • Bacteria / metabolism
  • Bacterial Infections / immunology*
  • Bacterial Proteins / administration & dosage
  • Bacterial Proteins / immunology
  • Bacterial Proteins / metabolism
  • Bacterial Toxins / immunology*
  • Bacterial Toxins / metabolism
  • Cell Membrane / metabolism
  • Cell Membrane Permeability / immunology
  • Cells, Cultured
  • Disease Models, Animal
  • Disease Susceptibility / immunology
  • Female
  • Host Microbial Interactions / immunology
  • Humans
  • Hydroxycholesterols / metabolism*
  • Interferons / isolation & purification*
  • Intravital Microscopy
  • Male
  • Mice
  • Mice, Transgenic
  • Phagocytes / cytology
  • Phagocytes / immunology*
  • Phagocytes / metabolism
  • Primary Cell Culture
  • Steroid Hydroxylases / genetics
  • Steroid Hydroxylases / metabolism
  • Streptolysins / administration & dosage
  • Streptolysins / immunology*
  • Streptolysins / metabolism

Substances

  • Bacterial Proteins
  • Bacterial Toxins
  • Hydroxycholesterols
  • Streptolysins
  • streptolysin O
  • 25-hydroxycholesterol
  • Interferons
  • Steroid Hydroxylases
  • cholesterol 25-hydroxylase