title: Differential regulation of cytokine production by PI3Kdelta in human monocytes upon acute and chronic inflammatory conditions.
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.
authors.affiliation: Division of Immunology and Allergy, Clinical Immunology Unit, Hans Wilsdorf Laboratory, Department of Internal Medicine, University Hospital and School of Medicine, University of Geneva, 24 rue Micheli-du-Crest, CH-1211 Geneva 14, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molnarfi
authors.forename: Karim J
authors.initials: KJ
authors.lastname: Brandt
authors.forename: Lyssia
authors.initials: L
authors.lastname: Gruaz
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Dayer
authors.forename: Danielle
authors.initials: D
authors.lastname: Burger
mesh_terms: D000208:Acute Disease; D002460:Cell Line; D002469:Cell Separation; D002908:Chronic Disease; D058534:Class I Phosphatidylinositol 3-Kinases; D058544:Class Ib Phosphatidylinositol 3-Kinase; D016207:Cytokines / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D007249:Inflammation / Q000201:enzymology*; D053590:Interleukin 1 Receptor Antagonist Protein / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D009000:Monocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D058534:Class I Phosphatidylinositol 3-Kinases; D058544:Class Ib Phosphatidylinositol 3-Kinase; D016207:Cytokines; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D053590:Interleukin 1 Receptor Antagonist Protein; D053583:Interleukin-1beta; D015850:Interleukin-6; D007527:Isoenzymes; D008070:Lipopolysaccharides; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D014409:Tumor Necrosis Factor-alpha; C486018:PIK3CD protein, human; C546760:PIK3CG protein, human; C000605506:GSK3B protein, human