PUBLICATION

Phenolic Glycolipid Facilitates Mycobacterial Escape from Microbicidal Tissue-Resident Macrophages

Authors
Cambier, C.J., O'Leary, S.M., O'Sullivan, M.P., Keane, J., Ramakrishnan, L.
ID
ZDB-PUB-170829-5
Date
2017
Source
Immunity   47(3): 552-565.e4 (Journal)
Registered Authors
Cambier, CJ, Ramakrishnan, Lalita
Keywords
none
MeSH Terms
  • Animals
  • Chemokine CCL2/metabolism
  • Chemotaxis/immunology
  • Cytokines/metabolism
  • Disease Models, Animal
  • Gene Knockout Techniques
  • Glycolipids/immunology*
  • Humans
  • Inflammation Mediators/metabolism
  • Macrophages/microbiology*
  • Macrophages/physiology*
  • Macrophages, Alveolar/microbiology
  • Macrophages, Alveolar/physiology
  • Membrane Proteins/metabolism
  • Monocytes/immunology
  • Monocytes/metabolism
  • Monocytes/microbiology
  • Mutation
  • Mycobacterium tuberculosis/genetics
  • Mycobacterium tuberculosis/immunology*
  • Organ Specificity/immunology
  • Tuberculosis/immunology
  • Tuberculosis/metabolism
  • Tuberculosis/microbiology
  • Zebrafish
PubMed
28844797 Full text @ Immunity
Abstract
Mycobacterium tuberculosis (Mtb) enters the host in aerosol droplets deposited in lung alveoli, where the bacteria first encounter lung-resident alveolar macrophages. We studied the earliest mycobacterium-macrophage interactions in the optically transparent zebrafish. First-responding resident macrophages phagocytosed and eradicated infecting mycobacteria, suggesting that to establish a successful infection, mycobacteria must escape out of the initially infected resident macrophage into growth-permissive monocytes. We defined a critical role for mycobacterial membrane phenolic glycolipid (PGL) in engineering this transition. PGL activated the STING cytosolic sensing pathway in resident macrophages, inducing the production of the chemokine CCL2, which in turn recruited circulating CCR2+ monocytes toward infection. Transient fusion of infected macrophages with CCR2+ monocytes enabled bacterial transfer and subsequent dissemination, and interrupting this transfer so as to prolong mycobacterial sojourn in resident macrophages promoted clearing of infection. Human alveolar macrophages produced CCL2 in a PGL-dependent fashion following infection, arguing for the potential of PGL-blocking interventions or PGL-targeting vaccine strategies in the prevention of tuberculosis. VIDEO ABSTRACT.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping