Azithromycin inhibits macrophage interleukin-1β production through inhibition of activator protein-1 in lipopolysaccharide-induced murine pulmonary neutrophilia

Int Immunopharmacol. 2011 Apr;11(4):424-34. doi: 10.1016/j.intimp.2010.12.010. Epub 2010 Dec 30.


Macrolide antibiotics, including azithromycin, also possess anti-inflammatory properties. However, the molecular mechanism(s) of activity as well as the target cells for their action have not been unambiguously identified as yet. In this study, the effects of azithromycin on lipopolysaccharide (LPS)-induced pulmonary neutrophilia were investigated in mice. Using immunohistochemistry, mRNA and specific protein assays, we confirmed that azithromycin ameliorates LPS-induced pulmonary neutrophilia by inhibiting interleukin-1β (IL-1β) expression and production selectively in alveolar macrophages as well as in LPS-stimulated J774.2 macrophage-derived cells in vitro. Inhibition by azithromycin of neutrophilia and IL-1β was accompanied by prevention of nuclear expression of activator protein-1 (AP-1) in both alveolar macrophages and J774.2 cells. The macrolide did not alter nuclear factor kappa B (NF-κB) or extracellular signal-regulated kinase 1/2 (ERK1/2) expression, activation or localization in LPS-stimulated lungs or in J774.2 cells. In conclusion, we have shown that inhibition of LPS-induced pulmonary neutrophilia and IL-1β concentrations in lung tissue following azithromycin treatment is mediated through effects on alveolar macrophages. In addition, we have shown for the first time, in an in vivo model, that azithromycin inhibits AP-1 activation in alveolar macrophages, an action confirmed on J774.2 cells in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Azithromycin / pharmacology*
  • Bronchoalveolar Lavage Fluid / cytology
  • Bronchoalveolar Lavage Fluid / immunology
  • Cell Line
  • Enzyme-Linked Immunosorbent Assay
  • Extracellular Signal-Regulated MAP Kinases / immunology
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Immunohistochemistry
  • Interleukin-1beta / biosynthesis*
  • Interleukin-1beta / immunology
  • Lipopolysaccharides / toxicity
  • Lung / drug effects
  • Lung / immunology*
  • Lung / metabolism
  • Macrophages / drug effects
  • Macrophages / immunology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / immunology
  • NF-kappa B / metabolism
  • Neutrophil Infiltration / drug effects*
  • Neutrophil Infiltration / immunology
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factor AP-1 / antagonists & inhibitors*


  • Anti-Inflammatory Agents, Non-Steroidal
  • Interleukin-1beta
  • Lipopolysaccharides
  • NF-kappa B
  • Transcription Factor AP-1
  • lipopolysaccharide, Escherichia coli O111 B4
  • Azithromycin
  • Extracellular Signal-Regulated MAP Kinases