Abstract
Delta-toxin from Staphylococcus aureus is responsible for various pathophysiologic effects. By studying different cell types in binding of delta-toxin in low, noncytotoxic concentrations, a specific binding of fluorescein-labeled delta-toxin to neutrophils and monocytes was found. Studying direct effects of delta-toxin on neutrophils, a dose-dependent up-regulation of complement receptor 3 expression was found. Oxygen radical production, as determined by Luminol-enhanced chemiluminescence, was not directly induced by delta-toxin, and this toxin was also unable to prime neutrophils for an enhanced response to FMLP or complement-opsonized zymosan. However, the priming response induced by lipopolysaccharide or tumor necrosis factor-alpha (TNF-alpha) was significantly further enhanced in the presence of delta-toxin. Furthermore, as a direct effect on human monocytes, delta-toxin induced TNF-alpha production. These data provide evidence that delta-toxin has direct and indirect effects on the activity of neutrophils and monocytes with regard to its proinflammatory capacity.
MeSH terms
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Bacterial Proteins / chemical synthesis
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Bacterial Proteins / metabolism*
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Bacterial Proteins / pharmacology
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Complement System Proteins / immunology
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Hemolysin Proteins / metabolism*
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Hemolysin Proteins / pharmacology
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Humans
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Lipopolysaccharides / metabolism
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Lipopolysaccharides / pharmacology
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Luminescent Measurements
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Macrophage-1 Antigen / metabolism
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Monocytes / metabolism
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Monocytes / microbiology
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N-Formylmethionine Leucyl-Phenylalanine / pharmacology
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Neutrophils / metabolism*
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Neutrophils / microbiology
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Reactive Oxygen Species / metabolism
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Receptors, Formyl Peptide
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Receptors, Immunologic / metabolism
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Receptors, Peptide / metabolism
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Respiratory Burst*
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Staphylococcus aureus / metabolism*
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Tumor Necrosis Factor-alpha / metabolism
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Tumor Necrosis Factor-alpha / pharmacology
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Up-Regulation
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Zymosan / pharmacology
Substances
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Bacterial Proteins
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Hemolysin Proteins
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Lipopolysaccharides
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Macrophage-1 Antigen
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Reactive Oxygen Species
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Receptors, Formyl Peptide
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Receptors, Immunologic
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Receptors, Peptide
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Tumor Necrosis Factor-alpha
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N-Formylmethionine Leucyl-Phenylalanine
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delta hemolysin protein, Staphylococcus aureus
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Complement System Proteins
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Zymosan