Staphylococcal superantigen-like 5 binds PSGL-1 and inhibits P-selectin-mediated neutrophil rolling

Blood. 2007 Apr 1;109(7):2936-43. doi: 10.1182/blood-2006-06-015461.

Abstract

Staphylococcus aureus secretes several virulence factors interfering with host-cell functions. Staphylococcal superantigen-like (SSL) proteins are a family of 11 exotoxins with structural homology to superantigens but with generally unknown functions. Recently, we described that chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS(31-121)), a potent inhibitor of C5a-induced responses, is structurally homologous to the C-terminal domain of SSL5. Here, we identify P-selectin glycoprotein ligand-1 (PSGL-1), involved in the initial rolling of neutrophils along the endothelium, as a target for SSL5. SSL5 specifically bound to Chinese hamster ovary cells stably expressing PSGL-1 (CHO-PSGL-1), which was dependent of sulfation and sialylation. Furthermore, SSL5 bound to PSGL-1/Ig fusion protein immobilized on a biosensor chip. SSL5 affected binding of soluble P-selectin/Fc chimera, the principle ligand of PSGL-1, to CHO-PSGL-1 cells and inhibited adhesion of neutrophils to immobilized P-selectin under static conditions. Under flow conditions SSL5 strongly decreased neutrophil rolling on immobilized P-selectin/Fc and activated human endothelial cells. In conclusion, SSL5 interferes with the interaction between PSGL-1 and P-selectin, suggesting that S aureus uses SSL5 to prevent neutrophil extravasation toward the site of infection. This makes SSL5 a potential lead for the development of new anti-inflammatory compounds for disorders characterized by excessive recruitment of leukocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Toxins / metabolism
  • Bacterial Toxins / toxicity
  • Base Sequence
  • Binding, Competitive
  • CHO Cells
  • Cells, Cultured
  • Cloning, Molecular
  • Cricetinae
  • Cricetulus
  • DNA, Bacterial / genetics
  • Exotoxins / metabolism
  • Exotoxins / toxicity
  • Humans
  • In Vitro Techniques
  • Leukocyte Rolling / drug effects*
  • Leukocyte Rolling / physiology
  • Membrane Glycoproteins / metabolism*
  • Neutrophils / drug effects*
  • Neutrophils / physiology*
  • P-Selectin / metabolism*
  • Protein Binding
  • Recombinant Proteins / metabolism
  • Recombinant Proteins / toxicity
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / immunology
  • Staphylococcus aureus / pathogenicity*
  • Superantigens / genetics
  • Superantigens / metabolism*
  • Superantigens / toxicity*

Substances

  • Bacterial Toxins
  • DNA, Bacterial
  • Exotoxins
  • Membrane Glycoproteins
  • P-Selectin
  • P-selectin ligand protein
  • Recombinant Proteins
  • Superantigens