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Invasion of Human Cells by a Bacterial Pathogen
07:15

Invasion of Human Cells by a Bacterial Pathogen

Published on: March 21, 2011

Role of M3 protein in the adherence and internalization of an invasive Streptococcus pyogenes strain by epithelial

Osnat Eyal1, Jeries Jadoun, Arcady Bitler

  • 1Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel.

FEMS Immunology and Medical Microbiology
|October 3, 2003
PubMed

Insights

Streptococcus pyogenes M3 protein aids bacterial adherence and internalization into host cells. Other bacterial proteins, not M3, are key targets for SpeB activity, influencing bacterial entry.

Area of Science:

  • Microbiology
  • Cell Biology
  • Infectious Diseases

Background:

  • Streptococcus pyogenes uses various mechanisms to adhere to and enter epithelial cells.
  • M protein is implicated in these processes, but M3 protein's role is poorly understood.
  • M3 serotype strains are linked to severe invasive infections.

Purpose of the Study:

  • To investigate the role of M3 protein in Streptococcus pyogenes adherence and internalization.
  • To explore the interaction of M3 protein with HEp-2 cells.
  • To determine the relationship between M3 protein and SpeB activity in bacterial invasion.

Main Methods:

  • Construction of an emm3 mutant of an invasive M3 serotype strain (SP268).
  • Assessing bacterial adherence and internalization by HEp-2 cells.
  • Utilizing speB and speB/emm3 double mutants to analyze protein interactions.

Main Results:

  • The M3 protein is involved in both adherence to and internalization by HEp-2 cells.
  • Fibronectin enhances SP268 adherence and internalization via an M3-independent pathway.
  • M3 protein is not essential for SpeB maturation, and SpeB's inhibition of internalization is M3-independent.

Conclusions:

  • M3 protein plays a significant role in Streptococcus pyogenes adherence and internalization.
  • SpeB inhibits bacterial internalization through targets other than intact M3 protein.
  • Further research is needed to identify other bacterial proteins involved in SpeB-mediated internalization.

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