Induction of NF-kappaB nuclear translocation in human respiratory epithelial cells by group A streptococci.
The activation of the transcription factor NF-kappaB and the production of inflammatory mediators play an essential role in the host response to pathogenic organisms. The objective of this study was to investigate the ability of group A streptococci (GAS) to stimulate the nuclear translocation of NF-kappaB in cultured human epithelial (HEp-2) cells. Infection of HEp-2 cells with a strain of Streptococcus pyogenes capable to efficiently internalize HEp-2 cells (strain A40) resulted in translocation of NF-kappaB during the first 15 min of infection, reaching a peak after 30 min that persisted at slightly lower levels 1h thereafter. Inhibition of bacterial internalization by cytochalasin D resulted in lower levels of nuclear NF-kappaB at 30 min and 1h of infection, however, it did not affect the initial nuclear translocation of NF-kappaB observed at 15 min postinfection. These results suggest that adhesion of S. pyogenes alone might be sufficient to stimulate nuclear translocation of NF-kappaB, however, bacterial internalization is required for a sustained nuclear translocation of this transcriptional factor.
Medina
Eva
E
Department of Microbial Pathogenesis and Vaccine Research, GBF-National Research Centre for Biotechnology, Braunschweig, Germany. eme@gbf.de
Anders
Dorothea
D
Chhatwal
Gursharan S
GS
D021581:Active Transport, Cell Nucleus; D001422:Bacterial Adhesion; D002467:Cell Nucleus / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000472:pathogenicity* / Q000502:physiology; D014407:Tumor Cells, Cultured
D016328:NF-kappa B