title: Inhibition of a p38/stress-activated protein kinase-2-dependent phosphatase restores function of IL-1 receptor-associate kinase-1 and reverses Toll-like receptor 2- and 4-dependent tolerance of macrophages.
abstract: Pretreatment of macrophages with Toll-like receptor (TLR)2 or TLR4 agonists leads to a stage of cell hyporesponsiveness to a second stimulation with TLR agonists. This tolerance state is accompanied by the repression of IL-1 receptor-associated kinase-1, mitogen-activated protein kinases, and IkappaB phosphorylation and expression of genes encoding proinflammatory cytokines, like IL-1beta and TNF-alpha. In this report, we demonstrated that mucin-like glycoprotein (tGPI-mucin) of Trypanosoma cruzi trypomastigotes (TLR2 agonist) and LPS (TLR4 agonist) induce cross-tolerance in macrophages and we addressed the role of phosphatase activity in this process. Analysis of the kinetic of phosphatase activity induced by tGPI-mucin or LPS revealed maximum levels between 12 and 24 h, which correlate with the macrophage hyporesponsiveness stage. The addition of okadaic acid, an inhibitor of phosphatase activity, reversed macrophage hyporesponsiveness after exposure to either LPS or tGPI-mucin, allowing phosphorylation of IL-1R-associated kinase-1, mitogen-activated protein kinases, and IkappaB and leading to TNF-alpha gene transcription and cytokine production. Furthermore, pretreatment with either the specific p38/stress-activated protein kinase-2 inhibitor (SB203580) or the NF-kappaB translocation inhibitor (SN50) prevented the induction of phosphatase activity and hyporesponsiveness in macrophage, permitting cytokine production after restimulation with LPS. These results indicate a critical role of p38/stress-activated protein kinase-2 and NF-kappaB-dependent phosphatase in macrophage hyporesponsiveness induced by microbial products that activate TLR2 and TLR4.
authors.affiliation: Centro de Pesquisas René Rachou, Fundaçao Oswaldo Cruz, Brazil. ropert@hotmail.com
authors.forename: Catherine
authors.initials: C
authors.lastname: Ropert
authors.forename: Meire
authors.initials: M
authors.lastname: Closel
authors.forename: Andréa C L
authors.initials: AC
authors.lastname: Chaves
authors.forename: Ricardo T
authors.initials: RT
authors.lastname: Gazzinelli
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D005419:Flavonoids / Q000494:pharmacology; D015870:Gene Expression / Q000276:immunology; D017261:Glycosylphosphatidylinositols / Q000494:pharmacology; D051550:I-kappa B Kinase; D007093:Imidazoles / Q000494:pharmacology; D007108:Immune Tolerance / Q000187:drug effects / Q000235:genetics; D053592:Interleukin-1 Receptor-Associated Kinases; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000819:agonists* / Q000172:deficiency / Q000235:genetics; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D009077:Mucins / Q000494:pharmacology; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D019319:Okadaic Acid / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors*; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000819:agonists* / Q000172:deficiency / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000276:immunology; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014349:Trypanosoma cruzi / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D005419:Flavonoids; D017261:Glycosylphosphatidylinositols; D007093:Imidazoles; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D009077:Mucins; D016328:NF-kappa B; D010455:Peptides; D011725:Pyridines; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C118258:SN50 peptide; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D019319:Okadaic Acid; D011494:Protein Kinases; D053592:Interleukin-1 Receptor-Associated Kinases; D017346:Protein Serine-Threonine Kinases; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D010744:Phosphoric Monoester Hydrolases; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one