Scientific article
OA Policy
English

IRG and GBP Host Resistance Factors Target Aberrant, “Non-self” Vacuoles Characterized by the Missing of “Self” IRGM Proteins

Published inPLOS pathogens, vol. 9, no. 6, e1003414
Publication date2013
First online date2013-06-13
Abstract

Interferon-inducible GTPases of the Immunity Related GTPase (IRG) and Guanylate Binding Protein (GBP) families provide resistance to intracellular pathogenic microbes. IRGs and GBPs stably associate with pathogen-containing vacuoles (PVs) and elicit immune pathways directed at the targeted vacuoles. Targeting of Interferon-inducible GTPases to PVs requires the formation of higher-order protein oligomers, a process negatively regulated by a subclass of IRG proteins called IRGMs. We found that the paralogous IRGM proteins Irgm1 and Irgm3 fail to robustly associate with "non-self" PVs containing either the bacterial pathogen Chlamydia trachomatis or the protozoan pathogen Toxoplasma gondii. Instead, Irgm1 and Irgm3 reside on "self" organelles including lipid droplets (LDs). Whereas IRGM-positive LDs are guarded against the stable association with other IRGs and GBPs, we demonstrate that IRGM-stripped LDs become high affinity binding substrates for IRG and GBP proteins. These data reveal that intracellular immune recognition of organelle-like structures by IRG and GBP proteins is partly dictated by the missing of "self" IRGM proteins from these structures.

Keywords
  • Animals
  • Cell Line
  • Chlamydia Infections / genetics
  • Chlamydia Infections / immunology
  • Chlamydia Infections / metabolism
  • Chlamydia trachomatis / immunology
  • Chlamydia trachomatis / metabolism
  • GTP Phosphohydrolases / genetics
  • GTP Phosphohydrolases / immunology
  • GTP Phosphohydrolases / metabolism
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / immunology
  • GTP-Binding Proteins / metabolism
  • Immunity, Innate
  • Mice
  • Mice, Knockout
  • Toxoplasma / immunology
  • Toxoplasma / metabolism
  • Toxoplasmosis / genetics
  • Toxoplasmosis / immunology
  • Toxoplasmosis / metabolism
  • Vacuoles / genetics
  • Vacuoles / immunology
  • Vacuoles / metabolism
  • Vacuoles / microbiology
  • Vacuoles / parasitology
UNIGE affiliation entities Not a UNIGE publication
Citation (ISO format)
HALDAR, Arun K et al. IRG and GBP Host Resistance Factors Target Aberrant, “Non-self” Vacuoles Characterized by the Missing of “Self” IRGM Proteins. In: PLOS pathogens, 2013, vol. 9, n° 6, p. e1003414. doi: 10.1371/journal.ppat.1003414
Main files (1)
Article (Published version)
Identifiers
Additional URL for this publicationhttps://dx.plos.org/10.1371/journal.ppat.1003414
Journal ISSN1553-7366
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