IL-36/LXR axis modulates cholesterol metabolism and immune defense to Mycobacterium tuberculosis

Sci Rep. 2018 Jan 24;8(1):1520. doi: 10.1038/s41598-018-19476-x.

Abstract

Mycobacterium tuberculosis (Mtb) is a life-threatening pathogen in humans. Bacterial infection of macrophages usually triggers strong innate immune mechanisms, including IL-1 cytokine secretion. The newer member of the IL-1 family, IL-36, was recently shown to be involved in cellular defense against Mtb. To unveil the underlying mechanism of IL-36 induced antibacterial activity, we analyzed its role in the regulation of cholesterol metabolism, together with the involvement of Liver X Receptor (LXR) in this process. We report that, in Mtb-infected macrophages, IL-36 signaling modulates cholesterol biosynthesis and efflux via LXR. Moreover, IL-36 induces the expression of cholesterol-converting enzymes and the accumulation of LXR ligands, such as oxysterols. Ultimately, both IL-36 and LXR signaling play a role in the regulation of antimicrobial peptides expression and in Mtb growth restriction. These data provide novel evidence for the importance of IL-36 and cholesterol metabolism mediated by LXR in cellular host defense against Mtb.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimicrobial Cationic Peptides / biosynthesis
  • Cholesterol / metabolism*
  • HEK293 Cells
  • Host-Pathogen Interactions*
  • Humans
  • Interleukin-1 / metabolism*
  • Liver X Receptors / metabolism*
  • Macrophages / immunology
  • Macrophages / microbiology
  • Mycobacterium tuberculosis / immunology*
  • THP-1 Cells
  • Tuberculosis / immunology*

Substances

  • Antimicrobial Cationic Peptides
  • Interleukin-1
  • Liver X Receptors
  • interleukin 36, human
  • Cholesterol