Co-Authors:
Sela, S., Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Tel-Aviv 69978, Israel
Marouni, M.J., Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Tel-Aviv 69978, Israel
Perry, R., Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Tel-Aviv 69978, Israel
Barzilai, A., Pediatric Infectious Diseases Unit, Chaim Sheba Medical Center, Tel-Hashomer Hospital, Tel-Hashomer, Israel
Abstract:
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 μg 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 μg 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. Copyright (C) 2000 Federation of European Microbiological Societies.