title: The effects of selective complement and CD14 inhibition on the E. coli-induced tissue factor mRNA upregulation, monocyte tissue factor expression, and tissue factor functional activity in human whole blood.
abstract: BACKGROUND
  The complement pathway and CD14 play essential roles in inflammation, but little is known about the relative roles of complement and CD14 in E. coli-induced tissue factor (TF) mRNA upregulation, expression by monocytes, and functional activity in human whole blood.
  
  
  METHODS
  Whole E. coli bacteria were incubated for up to 4 h in human whole blood containing the anticoagulant lepirudin, which does not affect complement activation. TF mRNA levels were analyzed using reverse transcription, quantitative real-time PCR (RT-qPCR), and the expression of TF on the cell surface was analyzed using flow cytometry. Complement was selectively inhibited using the C3 convertase inhibitor compstatin or a C5a receptor antagonist (C5aRa), while CD14 was blocked by an anti-CD14 F(ab')2 monoclonal antibody.
  
  
  RESULTS
  The E. coli-induced TF mRNA upregulation was reduced to virtually background levels by compstatin, whereas anti-CD14 had no effect. Monocyte TF expression and TF activity in plasma microparticles were significantly reduced by C5aRa. Anti-CD14 alone only slightly reduced E. coli-induced monocyte TF expression but showed a modest additive effect when combined with the complement inhibitors. Inhibiting complement and CD14 efficiently reduced the expression of the E. coli-induced cytokines IL-1beta, IL-6, IL-8, and platelet-derived growth factor bb.
  
  
  CONCLUSIONS
  Our results indicate that E. coli-induced TF mRNA upregulation is mainly dependent on complement activation, while CDI4 plays a modest role in monocyte TF expression and the plasma TF activity in human whole blood.
authors: Department of Laboratory Medicine, Nordland Hospital, Bodø, N-8092, Norway.
authors: O L
authors: OL
authors: Brekke
authors: C
authors: C
authors: Waage
authors: D
authors: D
authors: Christiansen
authors: H
authors: H
authors: Fure
authors: H
authors: H
authors: Qu
authors: John D
authors: JD
authors: Lambris
authors: B
authors: B
authors: Østerud
authors: E W
authors: EW
authors: Nielsen
authors: T E
authors: TE
authors: Mollnes
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000494:pharmacology / Q000627:therapeutic use; D051056:Complement Inactivating Agents / Q000627:therapeutic use*; D003165:Complement System Proteins / Q000378:metabolism; D016207:Cytokines / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000378:metabolism*; D005434:Flow Cytometry; D006629:Hirudins / Q000494:pharmacology; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000187:drug effects*; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D018805:Sepsis / Q000188:drug therapy / Q000382:microbiology; D013925:Thromboplastin / Q000096:biosynthesis*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000925:Anticoagulants; D051056:Complement Inactivating Agents; D016207:Cytokines; D006629:Hirudins; D018950:Lipopolysaccharide Receptors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D003165:Complement System Proteins; D013925:Thromboplastin; C083544:lepirudin