Autophagy protects against active tuberculosis by suppressing bacterial burden and inflammation

Proc Natl Acad Sci U S A. 2012 Nov 13;109(46):E3168-76. doi: 10.1073/pnas.1210500109. Epub 2012 Oct 23.

Abstract

Autophagy is a cell biological pathway affecting immune responses. In vitro, autophagy acts as a cell-autonomous defense against Mycobacterium tuberculosis, but its role in vivo is unknown. Here we show that autophagy plays a dual role against tuberculosis: antibacterial and anti-inflammatory. M. tuberculosis infection of Atg5(fl/fl) LysM-Cre(+) mice relative to autophagy-proficient littermates resulted in increased bacillary burden and excessive pulmonary inflammation characterized by neutrophil infiltration and IL-17 response with increased IL-1α levels. Macrophages from uninfected Atg5(fl/fl) LysM-Cre(+) mice displayed a cell-autonomous IL-1α hypersecretion phenotype, whereas T cells showed propensity toward IL-17 polarization during nonspecific activation or upon restimulation with mycobacterial antigens. Thus, autophagy acts in vivo by suppressing both M. tuberculosis growth and damaging inflammation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Autophagy / genetics
  • Autophagy / immunology*
  • Autophagy-Related Protein 5
  • Interleukin-17 / immunology
  • Interleukin-1alpha / genetics
  • Interleukin-1alpha / immunology
  • Macrophages / immunology
  • Mice
  • Mice, Transgenic
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / immunology*
  • Mycobacterium tuberculosis / immunology*
  • Neutrophil Infiltration / genetics
  • Neutrophil Infiltration / immunology
  • Neutrophils / immunology
  • Neutrophils / microbiology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / microbiology
  • Tuberculosis / genetics
  • Tuberculosis / immunology*
  • Tuberculosis / microbiology

Substances

  • Atg5 protein, mouse
  • Autophagy-Related Protein 5
  • Interleukin-17
  • Interleukin-1alpha
  • Microtubule-Associated Proteins