Study of Staphylococcal Toxic Shock Syndrome Toxin in Human Epithelial Cell Culture

J Infect Dis. 1984 Oct;150(4):535-45. doi: 10.1093/infdis/150.4.535.

Abstract

Staphylococcal toxic shock syndrome toxin (TST) inhibited growth of normal human epithelial (Chang) cells in culture, increasing the generation time 28% and 64% at concentrations of 4 X 10(-7)M and 8 X 10(-7)M, respectively. Fluorescence and electron microscopy of the cells treated with TST revealed the location of TST in the coated pits, specialized areas of the cell membrane known to contain high-affinity receptors for other polypeptide ligands. TST was labeled with 125I without detectable damage to the molecule and was shown to bind specifically to epithelial cells. A 100-fold excess of unlabeled TST inhibited binding of 125I-labeled toxin to the cells. Binding data indicated 10(4) receptor sites per cell for TST and a dissociation constant of 4 X 10(-9)M. Specific high-affinity binding of 125I-labeled TST to epithelial cells and the location of receptor sites in coated pits implies a possibility that the toxin is internalized by receptor-mediated endocytosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Bacterial Toxins / metabolism
  • Bacterial Toxins / toxicity*
  • Cells, Cultured
  • Epithelium / drug effects
  • Epithelium / ultrastructure
  • Fluorescent Antibody Technique
  • Humans
  • Iodine Radioisotopes
  • Microscopy, Electron
  • Rabbits
  • Shock, Septic / etiology*
  • Staphylococcal Infections / etiology*

Substances

  • Bacterial Toxins
  • Iodine Radioisotopes