Autophagy is a defense mechanism inhibiting BCG and Mycobacterium tuberculosis survival in infected macrophages.

Published

Journal Article

Mycobacterium tuberculosis is an intracellular pathogen persisting within phagosomes through interference with phagolysosome biogenesis. Here we show that stimulation of autophagic pathways in macrophages causes mycobacterial phagosomes to mature into phagolysosomes. Physiological induction of autophagy or its pharmacological stimulation by rapamycin resulted in mycobacterial phagosome colocalization with the autophagy effector LC3, an elongation factor in autophagosome formation. Autophagy stimulation increased phagosomal colocalization with Beclin-1, a subunit of the phosphatidylinositol 3-kinase hVPS34, necessary for autophagy and a target for mycobacterial phagosome maturation arrest. Induction of autophagy suppressed intracellular survival of mycobacteria. IFN-gamma induced autophagy in macrophages, and so did transfection with LRG-47, an effector of IFN-gamma required for antimycobacterial action. These findings demonstrate that autophagic pathways can overcome the trafficking block imposed by M. tuberculosis. Autophagy, which is a hormonally, developmentally, and, as shown here, immunologically regulated process, represents an underappreciated innate defense mechanism for control of intracellular pathogens.

Full Text

Duke Authors

Cited Authors

  • Gutierrez, MG; Master, SS; Singh, SB; Taylor, GA; Colombo, MI; Deretic, V

Published Date

  • December 17, 2004

Published In

Volume / Issue

  • 119 / 6

Start / End Page

  • 753 - 766

PubMed ID

  • 15607973

Pubmed Central ID

  • 15607973

International Standard Serial Number (ISSN)

  • 0092-8674

Digital Object Identifier (DOI)

  • 10.1016/j.cell.2004.11.038

Language

  • eng

Conference Location

  • United States