Polymyxin B stimulates production of complement components and cytokines in human monocytes.
Polymyxin B (PmB), an agent often used to neutralize the effects of bacterial lipopolysaccharide (LPS), was shown to exert a dose-dependent stimulatory effect on the biosynthesis of C3, factor B, interleukin-6 (IL-6), and granulocyte-macrophage colony-stimulating factor (GM-CSF) in human monocytes. A low dose of PmB (1 to 5 micrograms/ml) efficiently suppressed the LPS-induced (1 or 100 ng/ml) production of IL-6, GM-CSF, and factor B, but not the C3 production induced by 100 ng of LPS per ml. A reduced level of GM-CSF may have contributed to the persisting high C3 concentrations and the apparent lack of LPS inhibition in the latter situation, since GM-CSF is an inhibitor of monocyte C3 biosynthesis.
Høgåsen
A K
AK
Department of Pediatric Research, Rikshospitalet, National Hospital, Oslo Norway.
Abrahamsen
T G
TG
D003176:Complement C3 / Q000096:biosynthesis*; D011415:Complement Factor B / Q000096:biosynthesis*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D011112:Polymyxin B / Q000494:pharmacology*
D003176:Complement C3; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D011415:Complement Factor B; D011112:Polymyxin B