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Updated: Jun 28, 2026

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
Published on: January 3, 2020
Inhibition of endothelial interleukin-8 production and neutrophil transmigration by Staphylococcus aureus
Akiko Tajima1, Tadayuki Iwase, Hitomi Shinji
1Department of Bacteriology, Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan. tajima@jikei.ac.jp
Abstract:
Neutrophils play a crucial role in the host response to infection with Staphylococcus aureus, which is a major human pathogen capable of causing life-threatening disease. Interleukin-8 (IL-8) is a potent chemoattractant and activator of neutrophils. We previously reported that S. aureus secretes a factor that suppresses IL-8 production by human endothelial cells. Here we isolated an inhibitor of IL-8 production from the supernatant and identified it as staphylococcal beta-hemolysin. Beta-hemolysin reduced IL-8 production without cytotoxicity to endothelial cells. Pretreatment with beta-hemolysin decreased the expression of both IL-8 mRNA and protein induced by tumor necrosis factor alpha (TNF-alpha). Migration of neutrophils across TNF-alpha-activated endothelium was also inhibited by beta-hemolysin. In contrast, beta-hemolysin had no effect on intercellular adhesive molecule 1 expression in activated endothelial cells. These results showed that beta-hemolysin produced by S. aureus interferes with inflammatory signaling in endothelial cells and may help S. aureus evade the host immune response.
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