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Updated: Aug 25, 2025

Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
Published on: January 3, 2020
Antibacterial and anti-inflammatory properties of host defense peptides against Staphylococcus aureus
Leonardo Cecotto1,2, Kok van Kessel2, Margreet A Wolfert3
1Department of Orthopedics, University Medical Center Utrecht, 3508GA Utrecht, the Netherlands.
Abstract:
Cationic host defense peptides (HDPs) are a promising alternative to antibiotics in the fight against Staphylococcus aureus infections. In this study, we investigated the antibacterial and immunomodulatory properties of three HDPs namely IDR-1018, CATH-2, and LL-37. Although all three HDPs significantly inhibited LPS-induced activation of human macrophages, only CATH-2 prevented S. aureus growth. When applied to different infection models focused on intracellularly surviving bacteria, only IDR-1018 showed a consistent reduction in macrophage bacterial uptake. However, this observation did not correlate with an increase in killing the efficiency of intracellular S. aureus. Here, we conclude that despite the promising antibacterial and anti-inflammatory properties of the selected HDPs, macrophages' intrinsic antibacterial functions were not improved. Future studies should either focus on combining different HDPs or using them synergistically with other antibacterial agents to improve immune cells' efficacy against S. aureus pathogenesis.
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