Effect of the lipopolysaccharide antagonist Planktothrix sp. FP1 cyanobacterial extract on human polymorphonuclear leukocytes.
CyP is a lipopolysaccharide (LPS)-like molecule extracted from the freshwater cyanobacterium Oscillatoria planktothrix FP1, which has been reported to be a potent competitive inhibitor of bacterial LPS. In the present study the ability of CyP to affect human polymorphonuclear leukocyte (PMN) function was investigated. PMNs were isolated from venous blood by standard density-gradient centrifugation. Cell migration was measured by use of the Boyden chamber assay. Interleukin (IL)-8 and tumor necrosis factor (TNF)-α production was measured using a sandwich-type enzyme-linked immunosorbent assay. PMN intracellular reactive oxygen species (ROS) levels were assessed by the use of a fluorescent probe coupled to spectrophotometry. CyP 10-100 μg/ml was chemotactic for PMNs without affecting the chemotactic response to either E. coli LPS or N-formyl-Met-Leu-Phe (fMLP). CyP per se did not affect PMN production of either IL-8 or TNF-α, but concentration-dependently reduced LPS-induced production of both cytokines. On the contrary, CyP had no effect either on fMLP-induced production of IL-8 or on PMN oxidative burst (at rest and after stimulation with fMLP), a response which is known to be independent from LPS-operated pathways. In human PMNs CyP behaves as a selective and effective LPS antagonist. These findings support the therapeutic potential of CyP in endotoxin-dependent disease.
Department of Clinical Medicine, Section of Experimental and Clinical Pharmacology, University of Insubria, Varese, Italy.
Ramòna Consuèlo
RC
Maio
Marco
M
Cosentino
Carlo
C
Rossetti
Monica
M
Molteni
Sergio
S
Lecchini
Franca
F
Marino
D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000276:immunology; D000458:Cyanobacteria / Q000737:chemistry*; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D016209:Interleukin-8; D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium