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Cysteine proteinase SpeB from Streptococcus pyogenes - a potent modifier of immunologically important host and

Daniel C Nelson1, Julia Garbe, Mattias Collin

  • 1Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA. nelsond@umd.edu

Biological Chemistry
|November 5, 2011
PubMed

Insights

Group A Streptococcus secretes SpeB, a proteinase that degrades host and bacterial proteins. This review details SpeB substrates and its controversial role in streptococcal pathogenesis.

Area of Science:

  • Microbiology
  • Immunology
  • Biochemistry

Background:

  • Group A Streptococcus (S. pyogenes) is a human pathogen causing diverse diseases.
  • S. pyogenes must modulate host immune responses for pathogenesis.
  • SpeB, a major secreted cysteine proteinase, is crucial for S. pyogenes virulence.

Purpose of the Study:

  • To review known host and bacterial protein substrates of SpeB.
  • To identify SpeB cleavage sites on these substrates.
  • To discuss the role of SpeB in S. pyogenes pathogenesis based on current literature.

Main Methods:

  • Literature review of studies on SpeB substrates and functions.
  • Analysis of reported SpeB cleavage sites.
  • Synthesis of findings to evaluate SpeB's role in pathogenesis.

Main Results:

  • SpeB degrades numerous host proteins, including extracellular matrix components, cytokines, chemokines, complement, and immunoglobulins.
  • SpeB also degrades bacterial proteins, affecting surface proteins and virulence factors.
  • Identified cleavage sites reveal SpeB's broad specificity, but reported functions can yield contradictory results.

Conclusions:

  • SpeB's extensive substrate range highlights its significant impact on host-pathogen interactions.
  • Contradictory findings necessitate further research to clarify SpeB's precise role in streptococcal pathogenesis.
  • Understanding SpeB is critical for developing targeted therapies against S. pyogenes infections.

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