Staphylococcus aureus bicomponent leukocidin (Bicomponent leukocidin)

Staphylococcus aureus bicomponent leukocidins are a family of potent pore-forming toxins secreted by the bacterium Staphylococcus aureus to facilitate immune evasion and nutrient acquisition (Spaan et al., 2017, PubMed: 28545231). These toxins are composed of two distinct protein subunits, an S-component and an F-component, which assemble into a hetero-oligomeric pore on the plasma membrane of host immune cells. By targeting specific receptors such as C5aR1, CXCR1, and CXCR2, these toxins selectively lyse neutrophils, macrophages, and other leukocytes, thereby crippling the host's primary defense against infection (Spaan et al., 2013, PubMed: 23913162). They play a critical role in the pathogenesis of severe S. aureus infections, including necrotizing pneumonia and skin and soft tissue infections (Vandenesch et al., 2003, PubMed: 12732088). Therapeutic development has focused on neutralizing monoclonal antibodies, such as those in the ASN100 cocktail, which aim to prevent toxin-mediated leukocyte destruction and improve clinical outcomes in high-risk patients (Aridis Pharmaceuticals, 2021). Additionally, liposomal decoys like CAL02 are being investigated to sequester these toxins and prevent their interaction with host cells (Laterre et al., 2019, PubMed: 30638453).

Other names

Panton-Valentine LeukocidinPVLGamma-hemolysinLukABLukGHLukEDBicomponent pore-forming toxinHlgABHlgCB

Neutralization of toxin subunits (S and F components) to prevent their assembly into hetero-oligomeric pores on host cell membranes, thereby protecting immune cells from lysis.