Differential cytokine expression in human blood monocyte subpopulations: a polymerase chain reaction analysis.
The subpopulation of strongly CD14-positive (CD14++) monocytes and monocytes coexpressing the CD16 antigen and low levels of CD14 (CD14+/CD16+ cells) were isolated by fluorescence-activated cell sorting (FACS) followed by stimulation with lipopolysaccharide (LPS) at 1 micrograms/mL. Polymerase chain reaction (PCR) after reverse transcription of isolated mRNA (RT-PCR) revealed similar levels of tumor necrosis factor (TNF) transcripts in both subpopulations. By contrast, transcripts for interleukin-10 (IL-10) were only detectable in CD14++ monocytes, whereas CD14+/CD16+ cells produced no detectable IL-10 transcripts after 4 hours. Only after 16 hours of LPS stimulation was a low level of IL-10 transcripts discernible in CD14+/CD16+ monocytes. The same pattern was seen at the protein level in that TNF in LPS-stimulated supernatants was comparable for both subpopulations, whereas IL-10 was detected in CD14++ monocytes but not in CD14+/CD16+ cells. To avoid interference of cell activation by CD14 and CD16 antibodies, cells were also isolated based on the high and low level of CD33 antigen expression. Again, weakly CD33-positive cells, which comprise the CD14+/CD16+ cells, showed no or only minimal IL-10 mRNA. When comparing blood monocyte subpopulations with alveolar macrophages (AM), AM showed high levels of LPS-stimulated TNF, whereas IL-10 transcripts were undetectable. Our data show that CD14+/CD16+ blood monocytes produce high levels of proinflammatory cytokines like TNF, whereas the anti-inflammatory IL-10 is low or absent, a pattern similar to what is seen in AM.
Institute for Immunology, University of Munich, Germany.
M
M
Frankenberger
T
T
Sternsdorf
H
H
Pechumer
A
A
Pforte
H W
HW
Ziegler-Heitbrock
D001483:Base Sequence; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis; D018950:Lipopolysaccharide Receptors / Q000032:analysis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009000:Monocytes / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D015846:Monokines / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D017452:Receptors, IgG / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D015846:Monokines; D017452:Receptors, IgG; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10