Quantitative proteomics reveals the induction of mitophagy in tumor necrosis factor-α-activated (TNFα) macrophages

Mol Cell Proteomics. 2013 Sep;12(9):2394-407. doi: 10.1074/mcp.M112.025775. Epub 2013 May 14.

Abstract

Macrophages play an important role in innate and adaptive immunity as professional phagocytes capable of internalizing and degrading pathogens to derive antigens for presentation to T cells. They also produce pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) that mediate local and systemic responses and direct the development of adaptive immunity. The present work describes the use of label-free quantitative proteomics to profile the dynamic changes of proteins from resting and TNF-α-activated mouse macrophages. These analyses revealed that TNF-α activation of macrophages led to the down-regulation of mitochondrial proteins and the differential regulation of several proteins involved in vesicle trafficking and immune response. Importantly, we found that the down-regulation of mitochondria proteins occurred through mitophagy and was specific to TNF-α, as other cytokines such as IL-1β and IFN-γ had no effect on mitochondria degradation. Furthermore, using a novel antigen presentation system, we observed that the induction of mitophagy by TNF-α enabled the processing and presentation of mitochondrial antigens at the cell surface by MHC class I molecules. These findings highlight an unsuspected role of TNF-α in mitophagy and expanded our understanding of the mechanisms responsible for MHC presentation of self-antigens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen Presentation / drug effects
  • Antigens / metabolism
  • Autophagy / drug effects
  • Cell Line
  • Computational Biology
  • Down-Regulation / drug effects
  • Histocompatibility Antigens Class I / metabolism
  • Macrophage Activation / drug effects*
  • Macrophages / cytology*
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Macrophages / ultrastructure
  • Membrane Proteins / metabolism
  • Mice
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Mitochondrial Proteins / metabolism
  • Mitophagy / drug effects*
  • Phospholipases A2, Cytosolic / metabolism
  • Protein Interaction Maps / drug effects
  • Proteome / metabolism
  • Proteomics / methods*
  • Tumor Necrosis Factor-alpha / pharmacology*

Substances

  • Antigens
  • Histocompatibility Antigens Class I
  • Membrane Proteins
  • Mitochondrial Proteins
  • Proteome
  • Tumor Necrosis Factor-alpha
  • Phospholipases A2, Cytosolic