Activation of eosinophils by lipopolysaccharide-induced monocyte-derived cytokines.
BACKGROUND
Interactions between eosinophils and monocytes after lipopolysaccharide inhalation are yet to be investigated. The mechanism of eosinophil activation induced by lipopolysaccharide in the presence of monocytes was investigated.


METHODS
Expression of ICAM-1 and Mac-1 on eosinophils was evaluated after lipopolysaccharide stimulation in the presence of monocytes or monocyte culture supernatants. Cytokines in the supernatant of lipopolysaccharide-stimulated monocytes were measured using a cytokine array.


RESULTS
Expression of ICAM-1 and Mac-1 on eosinophils was up-regulated after lipopolysaccharide stimulation in the presence of monocytes or monocyte culture supernatant. Lipopolysaccharide induced secretion of ENA-78, GMCSF, GRO, IL-1 beta, IL-6, IL-10, MCP-1, TNF-alpha and MIP-3 alpha from monocytes. The up-regulation of ICAM-1, but not Mac-1, on eosinophils was attenuated by anti-TNF-alpha neutralizing antibody.


CONCLUSIONS
Monocyte-derived TNF-alpha plays an important role in the up-regulation of ICAM-I on eosinophils induced by lipopolysaccharides.
Kobayashi
Noriko
N
Department of Clinical and Laboratory Medicine, Akita University School of Medicine, Akita, Japan.
Kayaba
Hiroyuki
H
Takeda
Masahide
M
Yamaguchi
Kazutoshi
K
Chiba
Takahito
T
Ito
Wataru
W
Chihara
Junichi
J
D002450:Cell Communication; D016207:Cytokines / Q000502:physiology; D003907:Dexamethasone / Q000494:pharmacology; D004804:Eosinophils / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D018950:Lipopolysaccharide Receptors / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016177:Macrophage-1 Antigen / Q000096:biosynthesis; D009000:Monocytes / Q000276:immunology / Q000502:physiology*; D051197:Toll-Like Receptor 4 / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D016177:Macrophage-1 Antigen; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D003907:Dexamethasone