Sulfolipid-1 biosynthesis restricts Mycobacterium tuberculosis growth in human macrophages

ACS Chem Biol. 2012 May 18;7(5):863-70. doi: 10.1021/cb200311s. Epub 2012 Feb 24.

Abstract

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, is a highly evolved human pathogen characterized by its formidable cell wall. Many unique lipids and glycolipids from the Mtb cell wall are thought to be virulence factors that mediate host-pathogen interactions. An intriguing example is Sulfolipid-1 (SL-1), a sulfated glycolipid that has been implicated in Mtb pathogenesis, although no direct role for SL-1 in virulence has been established. Previously, we described the biochemical activity of the sulfotransferase Stf0 that initiates SL-1 biosynthesis. Here we show that a stf0-deletion mutant exhibits augmented survival in human but not murine macrophages, suggesting that SL-1 negatively regulates the intracellular growth of Mtb in a species-specific manner. Furthermore, we demonstrate that SL-1 plays a role in mediating the susceptibility of Mtb to a human cationic antimicrobial peptide in vitro, despite being dispensable for maintaining overall cell envelope integrity. Thus, we hypothesize that the species-specific phenotype of the stf0 mutant is reflective of differences in antimycobacterial effector mechanisms of macrophages.

Publication types

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

MeSH terms

  • Animals
  • Antimicrobial Cationic Peptides
  • Cathelicidins / pharmacology
  • Cell Line
  • Host-Pathogen Interactions*
  • Humans
  • Lipids / biosynthesis*
  • Lipids / chemistry
  • Macrophages / microbiology*
  • Mice
  • Mice, Inbred BALB C
  • Mycobacterium tuberculosis / drug effects
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / physiology*
  • Tuberculosis / drug therapy
  • Tuberculosis / microbiology

Substances

  • Antimicrobial Cationic Peptides
  • Cathelicidins
  • Lipids
  • sulfolipids