title: Interleukin-10 inhibits the induction of monocyte procoagulant activity by bacterial lipopolysaccharide.
abstract: Monocytes stimulated with bacterial lipopolysaccharide (LPS) generate a procoagulant activity (PCA) related to the induction of tissue factor (TF) expression at their surface. Since interleukin-10 (IL-10) was recently shown to inhibit LPS-induced cytokine production and is currently considered as a potential therapeutic agent in septic shock, we were interested to determine its effects on LPS-induced monocyte PCA. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with 1 microgram/ml LPS in the presence of serial dilutions of recombinant human IL-10 and PCA was determined after 6 h in a one-stage clotting assay. IL-10 inhibited in a dose-dependent manner LPS-induced TF-dependent PCA: a significant effect was already observed with 30 pg/ml IL-10 while 64-97% inhibition was achieved with 120 pg/ml IL-10. In parallel flow cytometry experiments, IL-10 was shown to block LPS-induced TF expression at the surface of monocytes. In order to inhibit LPS-induced PCA, IL-10 had to be added to PBMC at least 6 h before LPS challenge. This inhibitory effect of IL-10 was already apparent at the TF mRNA level and was prevented by co-incubation with cycloheximide (20 micrograms/ml). These data suggest that IL-10 acts via the induction of protein(s) which might interfere with TF gene transcription or mRNA stability. We conclude that the protective effects of IL-10 in endotoxinemia might be related not only to cytokine synthesis blockade but also to inhibition of LPS-induced PCA.
authors.affiliation: Department of Immunology-Hematology-Transfusion, Hôpital Erasme Université Libre de Bruxelles, Belgium.
authors.forename: O
authors.initials: O
authors.lastname: Pradier
authors.forename: C
authors.initials: C
authors.lastname: Gérard
authors.forename: A
authors.initials: A
authors.lastname: Delvaux
authors.forename: M
authors.initials: M
authors.lastname: Lybin
authors.forename: D
authors.initials: D
authors.lastname: Abramowicz
authors.forename: P
authors.initials: P
authors.lastname: Capel
authors.forename: T
authors.initials: T
authors.lastname: Velu
authors.forename: M
authors.initials: M
authors.lastname: Goldman
mesh_terms: D001483:Base Sequence; D001779:Blood Coagulation Factors / Q000096:biosynthesis*; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D066298:In Vitro Techniques; D016753:Interleukin-10 / Q000235:genetics / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology; D013925:Thromboplastin / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D001779:Blood Coagulation Factors; D017931:DNA Primers; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011994:Recombinant Proteins; C045071:leukocyte procoagulant activity; D016753:Interleukin-10; D013925:Thromboplastin