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The antibacterial activity of peptides derived from human beta-2 glycoprotein I is inhibited by protein H and M1

Maria Nilsson1, Sylwia Wasylik, Matthias Mörgelin

  • 1Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden. maria_e.nilsson@hotmail.com

Molecular Microbiology
|December 21, 2007
PubMed

Insights

Antibacterial peptides from beta-2 glycoprotein I fight bacteria. However, Streptococcus pyogenes uses surface proteins H and M1 to block these peptides, evading the immune response.

Area of Science:

  • Biochemistry
  • Immunology
  • Microbiology

Background:

  • Antibacterial peptides are crucial for innate immunity.
  • Beta-2 glycoprotein I (beta(2)GPI) is a human plasma protein with potential antibacterial properties.
  • Streptococcus pyogenes is a significant human pathogen that employs sophisticated evasion strategies.

Purpose of the Study:

  • To investigate the antibacterial activity of beta(2)GPI-derived peptides.
  • To elucidate the mechanisms by which Streptococcus pyogenes evades attacks by these peptides.

Main Methods:

  • Analysis of antibacterial activity of beta(2)GPI peptides against Gram-positive and Gram-negative bacteria.
  • Investigation of the interaction between S. pyogenes surface proteins (H and M1) and beta(2)GPI.
  • Assessment of the role of S. pyogenes proteins in inhibiting beta(2)GPI processing and peptide activity.

Main Results:

  • Peptides derived from beta(2)GPI exhibit antibacterial activity.
  • Streptococcus pyogenes proteins H and M1 bind to beta(2)GPI, preventing its cleavage into antibacterial peptides by neutrophil proteases.
  • These streptococcal proteins also bind and inhibit the activity of beta(2)GPI-derived antibacterial peptides.

Conclusions:

  • Streptococcal proteins H and M1 provide a novel resistance mechanism against beta(2)GPI-derived antibacterial peptides.
  • This interaction highlights a sophisticated immune evasion strategy employed by S. pyogenes.
  • Understanding this interaction could lead to new therapeutic approaches against bacterial infections.

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