title: Chemokine production and pattern recognition receptor (PRR) expression in whole blood stimulated with pathogen-associated molecular patterns (PAMPs).
abstract: Recognition of conserved bacterial structures called pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), may lead to induction of a variety of "early immediate genes" such as chemokines. In the current study, we have in an ex vivo whole blood model studied the induction of the chemokines MIP-1alpha, MCP-1 and IL-8 by various PAMPs. The rate of appearance of Escherichia coli-Lipopolysaccharide (LPS) induced chemokines differed. The production of MIP-1alpha and IL-8 was after 1 h of stimulation significantly higher when compared to unstimulated whole blood, whereas MCP-1 was not significantly elevated until after 3 h. At peak levels the MIP-1alpha concentration induced by E. coli-LPS was 3-5-fold higher than MCP-1 and IL-8. By specific cell depletion, we demonstrated that all three chemokines were mainly produced by monocytes. However, the mRNA results showed that IL-8 was induced in both monocytes and granulocytes. The production of all three chemokines, induced by the E. coli-LPS and Neisseria meningitidis-LPS, was significantly inhibited by antibodies against CD14 and TLR4, implying these receptors to be of importance for the effects of LPS in whole blood. The chemokine production induced by lipoteichoic acid (LTA) and non-mannose-capped lipoarabinomannan (AraLAM) was, however, less efficiently blocked by antibodies against CD14 and TLR2. E. coli-LPS and LTA induced a dose-dependent increase of CD14, TLR2 and TLR4 expression on monocytes in whole blood. These data show that PAMPs may induce chemokine production in whole blood and that antibodies against PRRs inhibit the production to different extent.
authors.affiliation: The Research and Development Group, Department of Clinical Chemistry, Ullevaal University Hospital, N-0450 Oslo, Norway. a.s.w.moller@medisin.uio.no
authors.forename: Anne-Sophie W
authors.initials: AS
authors.lastname: Møller
authors.forename: Reidun
authors.initials: R
authors.lastname: Ovstebø
authors.forename: Kari Bente F
authors.initials: KB
authors.lastname: Haug
authors.forename: Gun Britt
authors.initials: GB
authors.lastname: Joø
authors.forename: Ase-Brit
authors.initials: AB
authors.lastname: Westvik
authors.forename: Peter
authors.initials: P
authors.lastname: Kierulf
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000494:pharmacology; D018932:Chemokine CCL2 / Q000097:blood / Q000235:genetics; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018925:Chemokines / Q000097:blood* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects / Q000235:genetics; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000097:blood / Q000235:genetics; D047589:Leukocyte Reduction Procedures; D018950:Lipopolysaccharide Receptors / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins / Q000097:blood / Q000235:genetics; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051192:Receptors, Pattern Recognition / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013682:Teichoic Acids / Q000494:pharmacology; D051195:Toll-Like Receptor 2 / Q000097:blood / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000097:blood / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; C111835:CCL2 protein, human; D018932:Chemokine CCL2; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018925:Chemokines; D016209:Interleukin-8; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D019402:Macrophage Inflammatory Proteins; D011135:Polysaccharides, Bacterial; D012333:RNA, Messenger; D051192:Receptors, Pattern Recognition; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D013682:Teichoic Acids; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; C050016:lipoarabinomannan; C482199:lipopolysaccharide, E coli O55-B5; C009900:lipoteichoic acid; D006493:Heparin