Activation of a TGF-beta-specific multistep gene expression program in mature macrophages requires glucocorticoid-mediated surface expression of TGF-beta receptor II

J Immunol. 2008 May 15;180(10):6553-65. doi: 10.4049/jimmunol.180.10.6553.

Abstract

Alternatively activated (M2) macrophages regulate steady state-, cancer-, and inflammation-related tissue remodeling. They are induced by Th2-cytokines and glucocorticoids (GC). The responsiveness of mature macrophages to TGF-beta, a cytokine involved in inflammation, cancer, and atherosclerosis, is currently controversial. Recently, we demonstrated that IL-17 receptor B is up-regulated in human monocyte-derived macrophages differentiated in the presence of Th2 cytokines IL-4 and TGF-beta1. In this study, we show that mature human macrophages differentiated in the presence of IL-4, and dexamethasone (M2(IL-4/GC)) but not M2(IL-4) responds to TGF-beta1 which induced a gene expression program comprising 111 genes including transcriptional/signaling regulators (ID3 and RGS1), immune modulators (ALOX5AP and IL-17 receptor B) and atherosclerosis-related genes (ALOX5AP, ORL1, APOC1, APOC2, and APOE). Analysis of molecular mechanism underlying GC/TGF-beta cooperation revealed that surface expression of TGF-betaRII was high in M2(GC) and M2(IL-4/GC), but absent from M2(IL-4), whereas the expression of TGF-betaRI/II mRNA, TGF-betaRII total protein, and surface expression of TGF-betaRIII were unchanged. GC dexamethasone was essential for increased surface expression of functional TGF-betaRII because its effect was observed also in combination with IL-13, M-CSF, and GM-CSF. Prolonged Smad2-mediated signaling observed in TGF-beta1-treated M2(IL-4/GC) was due to insufficient activity of negative feedback mechanism what can be explained by up-regulation of SIRT1, a negative regulator of Smad7, and the retention of TGF-betaRII complex on the cell surface. In summary, mature human M2 macrophages made permissive to TGF-beta by GC-induced surface expression of TGF-betaRII activate in response to TGF-beta1, a multistep gene expression program featuring traits of macrophages found within an atherosclerotic lesion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Differentiation / immunology
  • Cell Membrane / metabolism
  • Flow Cytometry
  • Gene Expression Profiling
  • Gene Expression*
  • Glucocorticoids / metabolism*
  • Humans
  • Interleukin-4 / metabolism
  • Macrophage Activation / genetics*
  • Macrophage Activation / immunology
  • Macrophages / cytology
  • Macrophages / immunology
  • Macrophages / metabolism*
  • Oligonucleotide Array Sequence Analysis
  • RNA, Messenger / analysis
  • Receptors, Interleukin / biosynthesis
  • Receptors, Interleukin-17
  • Receptors, Transforming Growth Factor beta / biosynthesis*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transforming Growth Factor beta / metabolism*

Substances

  • Glucocorticoids
  • IL17RB protein, human
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-17
  • Receptors, Transforming Growth Factor beta
  • Transforming Growth Factor beta
  • Interleukin-4