The leukotriene B₄/BLT₁ axis is a key determinant in susceptibility and resistance to histoplasmosis

PLoS One. 2014 Jan 21;9(1):e85083. doi: 10.1371/journal.pone.0085083. eCollection 2014.

Abstract

The bioactive lipid mediator leukotriene B4 (LTB4) greatly enhances phagocyte antimicrobial functions against a myriad of pathogens. In murine histoplasmosis, inhibition of the LT-generating enzyme 5-lypoxigenase (5-LO) increases the susceptibility of the host to infection. In this study, we investigated whether murine resistance or susceptibility to Histoplasma capsulatum infection is associated with leukotriene production and an enhancement of in vivo and/or in vitro antimicrobial effector function. We show that susceptible C57BL/6 mice exhibit a higher fungal burden in the lung and spleen, increased mortality, lower expression levels of 5-LO and leukotriene B4 receptor 1 (BLT1) and decreased LTB4 production compared to the resistant 129/Sv mice. Moreover, we demonstrate that endogenous and exogenous LTs are required for the optimal phagocytosis of H. capsulatum by macrophages from both murine strains, although C57BL/6 macrophages are more sensitive to the effects of LTB4 than 129/Sv macrophages. Therefore, our results provide novel evidence that LTB4 production and BLT1 signaling are required for a histoplasmosis-resistant phenotype.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonate 5-Lipoxygenase / genetics
  • Arachidonate 5-Lipoxygenase / immunology
  • Disease Susceptibility
  • Enzyme Inhibitors / pharmacology
  • Gene Expression / immunology
  • Histoplasma / immunology*
  • Histoplasma / pathogenicity
  • Histoplasmosis / genetics
  • Histoplasmosis / immunology
  • Histoplasmosis / metabolism
  • Histoplasmosis / veterinary*
  • Host Specificity
  • Host-Pathogen Interactions
  • Leukotriene B4* / metabolism
  • Leukotriene B4* / pharmacology
  • Lung / drug effects
  • Lung / immunology
  • Lung / microbiology
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / microbiology
  • Mice
  • Mice, 129 Strain
  • Mice, Inbred C57BL
  • Phagocytosis / drug effects
  • Receptors, Leukotriene B4 / genetics
  • Receptors, Leukotriene B4 / immunology*
  • Rodent Diseases / genetics
  • Rodent Diseases / immunology*
  • Rodent Diseases / metabolism
  • Signal Transduction
  • Spleen / drug effects
  • Spleen / immunology
  • Spleen / microbiology

Substances

  • Enzyme Inhibitors
  • Ltb4r1 protein, mouse
  • Receptors, Leukotriene B4
  • Leukotriene B4
  • Arachidonate 5-Lipoxygenase