title: Involvement of phosphatidylinositol-phospholipase C in immune response to Salmonella lipopolysacharide in chicken macrophage cells (HD11).
abstract: The activation of phospholipases is one of the earliest key events in receptor-mediated cellular responses to a number of extracellular signaling molecules. Lipopolysaccharide (LPS) is a principle component of the outer membrane of Gram-negative bacteria and a prime target for recognition by the innate immune system. In the present study, we evaluated the role of specific phospholipase in the activation of a chicken macrophage cell line HD11 by LPS. Activation of HD11 cells by LPS results in induction of nitric oxide (NO). Using selective inhibitors, we have identified that phosphatidylinositol (PI)-phospholipase C (PI-PLC), but not phosphatidylcholine (PC)-phospholipase C (PC-PLC) nor PC-phospholipase D (PC-PLD), was required for LPS-induced NO production. Preincubation with PI-PLC selective inhibitors (U-73122 and ET-18-OCH3) abrogated LPS-induced NO production in HD11 cells, whereas PC-PLC inhibitor (D609), phosphatide phosphohydrolase inhibitor (propranolol), and PC-PLD inhibitor (n-butanol) had no inhibitory effects. We also showed that inhibition of protein kinase C (PKC) by selective inhibitors Ro 31-8220 and calphostin C and chelating intracellular Ca2+ by BAPTA-AM significantly reduced NO production in LPS-stimulated HD11 cells. Our results demonstrate that PI-PLC plays a critical role, most likely through activation of PKC pathway, in TLR4 mediated immune responses of avian macrophage cells to LPS.
authors.affiliation: Southern Plain Agricultural Research Center, USDA-ARS, College Station, TX 77845, USA. he@ffsru.usda.gov
authors.forename: Haiqi
authors.initials: H
authors.lastname: He
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Genovese
authors.forename: David J
authors.initials: DJ
authors.lastname: Nisbet
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kogut
mesh_terms: D000818:Animals; D002460:Cell Line; D002645:Chickens; D004963:Estrenes / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D009281:Naphthalenes / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000276:immunology; D043265:Phosphatidylinositol Diacylglycerol-Lyase / Q000037:antagonists & inhibitors / Q000276:immunology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C; D010742:Phospholipid Ethers / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000276:immunology; D011760:Pyrrolidinones / Q000494:pharmacology; D012477:Salmonella enteritidis; D051197:Toll-Like Receptor 4 / Q000276:immunology
chemical_list: D004963:Estrenes; D007211:Indoles; D008070:Lipopolysaccharides; D009281:Naphthalenes; D009573:Nitrites; D010726:Phosphodiesterase Inhibitors; D010742:Phospholipid Ethers; D011760:Pyrrolidinones; D051197:Toll-Like Receptor 4; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C026659:edelfosine; D009569:Nitric Oxide; D011493:Protein Kinase C; D054801:Phosphoinositide Phospholipase C; D043265:Phosphatidylinositol Diacylglycerol-Lyase; C058819:calphostin C; C064758:Ro 31-8220