TOLLIP deficiency is associated with increased resistance to Legionella pneumophila pneumonia

Mucosal Immunol. 2019 Nov;12(6):1382-1390. doi: 10.1038/s41385-019-0196-7. Epub 2019 Aug 28.


Legionella pneumophila (Lp) is a flagellated, intracellular bacterium that can cause Legionnaires' disease (LD). Lp activates multiple innate immune receptors, and TOLLIP dampens MyD88-dependent signaling and may influence susceptibility to LD. We evaluated the effect of TOLLIP on innate immunity, pneumonia severity, and LD susceptibility in mouse lungs and human populations. To accomplish this, we evaluated the effect of TOLLIP on lung-specific Lp control and immune response and associated a common functional TOLLIP variant with Lp-induced innate immune responses and LD susceptibility in humans. After aerosol Lp infection, Tollip-/- mice demonstrated significantly fewer bacterial colony-forming unit and increased cytokine responses from BAL fluid. Tollip-/- macrophages also suppressed intracellular Lp replication in a flagellin-independent manner. The presence of a previously characterized, functionally active SNP associated with decreased TOLLIP mRNA transcript in monocytes was associated with increased TNF and IL-6 secretion after Lp stimulation of PBMC ex vivo. This genotype was separately associated with decreased LD susceptibility (309 controls, 88 cases, p = 0.008, OR 0.36, 95% CI 0.16-0.76) in a candidate gene association study. These results suggest that TOLLIP decreases lung-specific TLR responses to increase LD susceptibility in human populations. Better understanding of TOLLIP may lead to novel immunomodulatory therapies.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Animals
  • Bacterial Load
  • Case-Control Studies
  • Cells, Cultured
  • Cytokines / metabolism
  • Disease Models, Animal
  • Female
  • Host-Pathogen Interactions
  • Humans
  • Immunity, Innate
  • Inflammation Mediators / metabolism
  • Intracellular Signaling Peptides and Proteins / deficiency*
  • Intracellular Signaling Peptides and Proteins / genetics
  • Legionella pneumophila / growth & development
  • Legionella pneumophila / immunology
  • Legionella pneumophila / pathogenicity*
  • Legionnaires' Disease / genetics
  • Legionnaires' Disease / immunology
  • Legionnaires' Disease / metabolism*
  • Legionnaires' Disease / microbiology
  • Lung / immunology
  • Lung / metabolism*
  • Lung / microbiology
  • Macrophages / immunology
  • Macrophages / metabolism
  • Macrophages / microbiology
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Middle Aged
  • Severity of Illness Index
  • Signal Transduction


  • Cytokines
  • Inflammation Mediators
  • Intracellular Signaling Peptides and Proteins
  • TOLLIP protein, human
  • Tollip protein, mouse