Differential regulation of cytokine production by PI3Kdelta in human monocytes upon acute and chronic inflammatory conditions

Mol Immunol. 2008 Jul;45(12):3419-27. doi: 10.1016/j.molimm.2008.04.001. Epub 2008 May 9.

Abstract

Deregulated production of cytokines, including IL-1beta, IL-6 and TNF plays an important role in chronic inflammation. Relevant to this condition, direct cellular contact with stimulated T cells is a potent inducer of cytokine production in human monocytes/macrophages. We previously demonstrated that PI3Ks regulate differential production of IL-1beta and its specific inhibitor secreted IL-1 receptor antagonist (sIL-1Ra) by human monocytes. Here we show that in contrast with PI3Kalpha, beta and gamma, PI3Kdelta accounts for most of the PI3K-dependent signaling ruling the production of IL-1beta, IL-6, TNF and sIL-1Ra in monocytes activated by cellular contact with stimulated T cells (mimicked by CHAPS-solubilized membranes of stimulated T cells, CE sHUT) and lipopolysaccharides (LPS); the latter stimuli being relevant to chronic/sterile and acute/infectious inflammation, respectively. Interestingly, PI3Kdelta activity dampened the production of pro-inflammatory cytokines in LPS-activated monocytes, but induced it in CE sHUT-activated cells. In both CE sHUT- and LPS-activated monocytes PI3Kdelta regulated cytokine transcript expression through the phosphorylation/inactivation of glycogen synthase kinase-3beta (GSK3beta). The blockade of GSK3beta displayed inverse effects to those of PI3Kdelta blockade. Thus, by displaying opposite functions in conditions mimicking chronic/sterile and acute/infectious inflammation, i.e., by repressing pro-inflammatory cytokine expression in LPS-activated monocytes but inducing such mediators in T cell contact-activated monocytes, PI3Kdelta represents a potential therapeutic target specific to chronic/sterile inflammatory conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Cell Line
  • Cell Separation
  • Chronic Disease
  • Class I Phosphatidylinositol 3-Kinases
  • Class Ib Phosphatidylinositol 3-Kinase
  • Cytokines / biosynthesis*
  • Enzyme Activation / drug effects
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 beta
  • Humans
  • Inflammation / enzymology*
  • Interleukin 1 Receptor Antagonist Protein / biosynthesis
  • Interleukin-1beta / biosynthesis
  • Interleukin-6 / biosynthesis
  • Isoenzymes / antagonists & inhibitors
  • Lipopolysaccharides / pharmacology
  • Lymphocyte Activation / drug effects
  • Monocytes / drug effects
  • Monocytes / enzymology*
  • Monocytes / immunology*
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoinositide-3 Kinase Inhibitors
  • Phosphorylation / drug effects
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Time Factors
  • Tumor Necrosis Factor-alpha / biosynthesis

Substances

  • Cytokines
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1beta
  • Interleukin-6
  • Isoenzymes
  • Lipopolysaccharides
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Tumor Necrosis Factor-alpha
  • Class I Phosphatidylinositol 3-Kinases
  • Class Ib Phosphatidylinositol 3-Kinase
  • PIK3CD protein, human
  • PIK3CG protein, human
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Proto-Oncogene Proteins c-akt
  • Glycogen Synthase Kinase 3