Related Experiment Videos
Effect of lipoteichoic acid on the uptake of Streptococcus pyogenes by HEp-2 cells
1Department of Human Microbiology, Sackler school of Medicine, Tel-Aviv University, Ramat Aviv, Israel. shlomos@post.tau.ac.il
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 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.
Insights
Exogenous lipoteichoic acid (LTA) from Streptococcus pyogenes inhibits bacterial entry into host cells. LTA internalization by epithelial cells suggests a cytotoxic effect on bacterial uptake mechanisms.
Area of Science:
- Microbiology
- Cell Biology
- Immunology
Background:
- Lipoteichoic acid (LTA) is implicated in host-pathogen interactions involving Streptococcus pyogenes.
- Understanding LTA's role in bacterial adherence and entry is crucial for deciphering infection mechanisms.
Purpose of the Study:
- To investigate the impact of exogenous lipoteichoic acid (LTA) on the adherence and internalization of Streptococcus pyogenes into HEp-2 epithelial cells.
- To explore the cellular mechanisms underlying LTA's effect on bacterial invasion.
Main Methods:
- Utilized HEp-2 epithelial cells and Streptococcus pyogenes JRS4 strain.
- Administered varying concentrations of exogenous LTA to assess adherence and entry.
- Employed binding assays and confocal laser microscopy for cellular localization studies.
Main Results:
- Exogenous LTA significantly inhibited bacterial entry in a dose-dependent manner, with minimal effect on adherence.
- LTA also reduced the entry of Salmonella typhimurium into HEp-2 cells.
- LTA was internalized by HEp-2 cells and co-localized with F-actin, suggesting interference with the actin cytoskeleton.
Conclusions:
- Exogenous LTA can enter host cells and exert a cytotoxic effect, potentially targeting the actin cytoskeleton.
- This LTA-induced cytotoxicity disrupts bacterial internalization processes, impacting pathogen invasion strategies.