Effect of lipoteichoic acid on the uptake of Streptococcus pyogenes by HEp-2 cells.
Lipoteichoic acid (LTA) is thought to play a role in the interactions between Streptococcus pyogenes and host cells. We have examined the effect of exogenous LTA on the adherence and entry of S. pyogenes JRS4 strain into HEp-2 epithelial cells. LTA markedly inhibited bacterial entry in a concentration-dependent manner, up to 250 microg ml(-1). In contrast, LTA had only a slight inhibitory effect on adherence. LTA also inhibited the entry but not adherence of Salmonella typhimurium strain into HEp-2 cells. Binding experiments showed a dose-dependent binding of LTA to cells up to 10 microg ml(-1). Confocal laser microscopy imaging and analysis revealed that LTA was internalized by the epithelial cells and colocalized with F-actin. These results might imply that, following binding, exogenous LTA enters HEp-2 cells and exerts a cytotoxic effect that interferes with bacterial internalization. A possible target for LTA activity might be the actin cytoskeleton, which is known to be essential for bacterial uptake.
Sela
S
S
Department of Human Microbiology, Sackler school of Medicine, Tel-Aviv University, Ramat Aviv, Israel. shlomos@post.tau.ac.il
Marouni
M J
MJ
Perry
R
R
Barzilai
A
A
D001422:Bacterial Adhesion / Q000187:drug effects; D003593:Cytoplasm / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology*; D006801:Humans; D008070:Lipopolysaccharides / Q000378:metabolism / Q000494:pharmacology*; D018613:Microscopy, Confocal; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000502:physiology*; D013682:Teichoic Acids / Q000378:metabolism / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid