title: Differential production of cytokines, reactive oxygen and nitrogen by bovine macrophages and dendritic cells stimulated with Toll-like receptor agonists.
abstract: Toll-like receptors (TLR) have been described as partially sharing signalling pathways but showing unique ligand specificity and tissue distribution. Here, the response of bovine macrophages (Mphi) and dendritic cells (DC), both derived from monocytes, was compared by exposing them to the TLR-specific ligands lipopolysaccharide, poly(I:C)-double-stranded RNA, and CpG-DNA, as well as inactivated Gram-negative and Gram-positive bacteria, shown to bind to TLR. The production of NO, superoxide anion, interleukin-10 (IL-10), IL-12 and tumour necrosis factor (TNF) was determined. Compared to monocytes, Mphi expressed more TLR2 and similar levels of TLR4 mRNA transcripts, as analysed by quantitative polymerase chain reaction, whereas DC expressed reduced amounts. Although both DC and Mphi recognized the TLR ligands, dramatic differences were seen in their reaction pattern to them. Both cell types responded with the production of TNF, but DC produced more IL-12, whereas Mphi produced more IL-10, regardless of the TLR agonist used. Co-stimulation with interferon-gamma influenced the amount of cytokine production, but did not alter the cell type-specific response pattern. Compared to Mphi, DC produced > 10 times less NO upon triggering with TLR ligands. In addition, DC produced superoxide anion to opsonized and non-opsonized zymosan, but not to phorbol 12-myristate 13-acetate, a response pattern confirmed for human Mphi and DC, respectively. Different protein kinase C isoforms and extracellular signal-regulated kinase patterns were detected in cell lysates of resting and stimulated Mphi and DC. Collectively, our results point to profound differences in pathogen-derived signal-response coupling occurring commensurate with distinct functions carried out by Mphi or DC.
authors.affiliation: Institute of Veterinary Virology, University of Bern, CH-3012 Bern, Switzerland. dwerling@rvc.ac.uk
authors.forename: Dirk
authors.initials: D
authors.lastname: Werling
authors.forename: Jayne C
authors.initials: JC
authors.lastname: Hope
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Howard
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Jungi
mesh_terms: D000818:Animals; D001419:Bacteria; D002417:Cattle; D002478:Cells, Cultured; D018899:CpG Islands; D016207:Cytokines / Q000096:biosynthesis*; D004247:DNA / Q000008:administration & dosage; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D011070:Poly I-C / Q000235:genetics; D011493:Protein Kinase C / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000032:analysis; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; D016753:Interleukin-10; D018664:Interleukin-12; D009569:Nitric Oxide; D004247:DNA; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D009584:Nitrogen; D011070:Poly I-C