title: The proinflammatory CD14+CD16+DR++ monocytes are a major source of TNF.
abstract: In human blood two monocyte populations can be distinguished, i.e., the CD14(++)CD16(-)DR(+) classical monocytes and the CD14(+)CD16(+)DR(++) proinflammatory monocytes that account for only 10% of all monocytes. We have studied TNF production in these two types of cells using three-color immunofluorescence and flow cytometry on whole peripheral blood samples stimulated with either LPS or with the bacterial lipopeptide S-(2,3-bis(palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser-(S)-Lys(4)-OH,trihydrochloride (Pam3Cys). After stimulation with LPS the median fluorescence intensity for TNF protein was 3-fold higher in the proinflammatory monocytes when compared with the classical monocytes. After stimulation with Pam3Cys they almost exclusively responded showing 10-fold-higher levels of median fluorescence intensity for TNF protein. The median fluorescence intensity for Toll-like receptor 2 cell surface protein was found 2-fold higher on CD14(+)CD16(+)DR(++) monocytes, which may explain, in part, the higher Pam3Cys-induced TNF production by these cells. When analyzing secretion of TNF protein into the supernatant in PBMCs after depletion of CD16(+) monocytes we found a reduction of LPS-induced TNF by 28% but Pam3Cys-induced TNF was reduced by 64%. This indicates that the minor population of CD14(+)CD16(+) monocytes are major producers of TNF in human blood.
authors.affiliation: Institute for Immunology, University of Muenchen, Germany.
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Belge
authors.forename: Farshid
authors.initials: F
authors.lastname: Dayyani
authors.forename: Alexia
authors.initials: A
authors.lastname: Horelt
authors.forename: Maciej
authors.initials: M
authors.lastname: Siedlar
authors.forename: Marion
authors.initials: M
authors.lastname: Frankenberger
authors.forename: Bernhard
authors.initials: B
authors.lastname: Frankenberger
authors.forename: Terje
authors.initials: T
authors.lastname: Espevik
authors.forename: Löms
authors.initials: L
authors.lastname: Ziegler-Heitbrock
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D002478:Cells, Cultured; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D029721:Drosophila Proteins; D005455:Fluorescent Antibody Technique; D006684:HLA-DR Antigens / Q000096:biosynthesis* / Q000097:blood; D006801:Humans; D018189:Immunomagnetic Separation; D016130:Immunophenotyping; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis* / Q000097:blood; D008070:Lipopolysaccharides / Q000494:pharmacology; D008074:Lipoproteins / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D009000:Monocytes / Q000145:classification / Q000276:immunology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics; D017452:Receptors, IgG / Q000096:biosynthesis* / Q000097:blood; D011971:Receptors, Immunologic / Q000378:metabolism; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D029721:Drosophila Proteins; D006684:HLA-DR Antigens; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008074:Lipoproteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017452:Receptors, IgG; D011971:Receptors, Immunologic; C495342:TLR2 protein, human; D051195:Toll-Like Receptor 2; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; C069172:2,3-bis(palmitoyloxy)-2-propyl-1-palmitoylcysteine; D003545:Cysteine