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Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells
09:25

Implementation of a Permeable Membrane Insert-based Infection System to Study the Effects of Secreted Bacterial Toxins on Mammalian Host Cells

Published on: August 19, 2016

The SpeB virulence factor of Streptococcus pyogenes, a multifunctional secreted and cell surface molecule with

J Hytönen1, S Haataja, D Gerlach

  • 1Department of Medical Biochemistry and Molecular Biology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland. jukka.hytonen@utu.fi

Molecular Microbiology
|January 3, 2001
PubMed

Insights

Streptococcus pyogenes SpeB protein binds to host glycoproteins like laminin. This surface-bound SpeB challenges previous views, offering new targets for vaccines and drugs against bacterial infections.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Immunology

Background:

  • Understanding pathogenic bacteria-host interactions is crucial for developing new vaccines and drugs.
  • Streptococcus pyogenes possesses a glycoprotein-binding activity called strepadhesin, regulated by the Mga virulence factor.

Purpose of the Study:

  • To identify the protein responsible for strepadhesin activity in Streptococcus pyogenes.
  • To characterize the role and localization of this protein in bacterial pathogenesis.

Main Methods:

  • Biochemical assays to identify the protein mediating strepadhesin activity.
  • Characterization of the identified protein's enzymatic and binding properties.
  • Analysis of the protein's localization on the bacterial cell surface.

Main Results:

  • Streptococcal pyrogenic exotoxin (SpeB), a cysteine protease, was identified as the protein responsible for strepadhesin activity.
  • SpeB mediates the binding of Streptococcus pyogenes to laminin and other host glycoproteins.
  • SpeB is found not only secreted but also unexpectedly tightly bound to the bacterial cell surface.

Conclusions:

  • SpeB functions as a surface-exposed molecule on Streptococcus pyogenes, in addition to its previously known extracellular protease role.
  • The surface localization and laminin-binding activity of SpeB present novel therapeutic and vaccine targets for treating Streptococcus pyogenes infections.

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