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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adjuvants, Immunologic / pharmacology
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Cells, Cultured
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Cysteine / analogs & derivatives*
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Cysteine / pharmacology
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Drosophila Proteins*
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Fluorescent Antibody Technique
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HLA-DR Antigens / biosynthesis*
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HLA-DR Antigens / blood
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Humans
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Immunomagnetic Separation
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Immunophenotyping
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Inflammation / immunology
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Inflammation / pathology
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Lipopolysaccharide Receptors / biosynthesis*
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Lipopolysaccharide Receptors / blood
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Lipopolysaccharides / pharmacology
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Lipoproteins / pharmacology
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Membrane Glycoproteins / biosynthesis
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Membrane Glycoproteins / genetics
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Monocytes / classification
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Monocytes / immunology*
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Monocytes / metabolism*
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RNA, Messenger / biosynthesis
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Receptors, Cell Surface / biosynthesis
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Receptors, Cell Surface / genetics
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Receptors, IgG / biosynthesis*
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Receptors, IgG / blood
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Receptors, Immunologic / metabolism
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Toll-Like Receptor 2
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Toll-Like Receptors
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Tumor Necrosis Factor-alpha / biosynthesis*
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Tumor Necrosis Factor-alpha / metabolism
Substances
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Adjuvants, Immunologic
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Drosophila Proteins
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HLA-DR Antigens
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Lipopolysaccharide Receptors
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Lipopolysaccharides
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Lipoproteins
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Membrane Glycoproteins
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RNA, Messenger
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Receptors, Cell Surface
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Receptors, IgG
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Receptors, Immunologic
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TLR2 protein, human
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Toll-Like Receptor 2
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Toll-Like Receptors
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Tumor Necrosis Factor-alpha
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2,3-bis(palmitoyloxy)-2-propyl-1-palmitoylcysteine
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Cysteine