CCR5 is a receptor for Staphylococcus aureus leukotoxin ED

Area of Science:

• Microbiology
• Immunology
• Toxicology

Background:

• Pore-forming toxins are key bacterial virulence factors.
• Staphylococcus aureus uses leukotoxins to kill host cells, particularly immune cells.
• The specific host targets of staphylococcal leukotoxins remain largely unknown.

Purpose of the Study:

• To identify host factors determining leukotoxin selectivity.
• To investigate the role of the identified factor in S. aureus pathogenesis.
• To explore therapeutic strategies targeting this interaction.

Main Methods:

• Cell-based assays to assess leukotoxin cytotoxicity.
• Identification of host cell receptors using genetic and biochemical approaches.
• In vivo studies using CCR5-deficient mice and infection models.
• Pharmacological inhibition using CCR5 antagonists.

Main Results:

• The HIV co-receptor CCR5 is identified as a critical determinant for S. aureus leukotoxin ED (LukED) targeting of myeloid cells and T lymphocytes.
• CCR5 antagonists, including the HIV drug maraviroc, effectively block LukED-mediated cell killing.
• CCR5-deficient mice exhibit significant resistance to lethal S. aureus infection.
• LukED-mediated depletion of CCR5(+) leukocytes represents a novel immune evasion strategy.

Conclusions:

• CCR5 is a cellular receptor exploited by S. aureus LukED for immune cell targeting.
• Targeting CCR5 offers a potential therapeutic strategy against S. aureus infections.
• Understanding this interaction reveals a new mechanism of bacterial immune evasion.