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Pneumococcus Infection of Primary Human Endothelial Cells in Constant Flow
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Procoagulant Activity of Blood and Microvesicles Is Disturbed by Pneumococcal Pneumolysin, Which Interacts with

Sonja Oehmcke-Hecht1, Claudia Maletzki2, Surabhi Surabhi3

  • 1Institute of Medical Microbiology, Virology and Hygiene, Rostock University Medical Center, Rostock, Germany.

Journal of Innate Immunity
|July 17, 2022
PubMed

Insights

Streptococcus pneumoniae impairs blood coagulation by releasing pneumolysin, which lyses mononuclear cells. This interaction, involving the innate immune and coagulation systems, may worsen lung injury during pneumonia.

Area of Science:

  • Immunology
  • Hematology
  • Microbiology

Background:

  • The coagulation and contact systems are integral to innate immunity, controlling bleeding and pathogen spread.
  • These systems also contribute to host defense through inflammatory responses and antimicrobial peptide release.

Purpose of the Study:

  • To investigate the impact of Streptococcus pneumoniae on the coagulation and contact systems.
  • To elucidate the mechanisms by which pneumococci influence blood coagulation.

Main Methods:

  • Studied the effect of S. pneumoniae, specifically its autolysis and pneumolysin release, on blood coagulation.
  • Investigated the interaction of pneumolysin with coagulation and contact system factors.
  • Examined the lysis of mononuclear cells and their procoagulant microvesicles.

Main Results:

  • S. pneumoniae, unlike other streptococci, impairs blood coagulation.
  • Pneumolysin released by pneumococci causes lysis of tissue factor-producing mononuclear cells and their microvesicles.
  • Pneumolysin binds to coagulation and contact system factors without causing activation.

Conclusions:

  • S. pneumoniae modulates coagulation system activation via pneumolysin release.
  • This modulation, particularly the lysis of mononuclear cells, may exacerbate lung injury in pneumococcal pneumonia.
  • Understanding this interaction is crucial for innate immunity and sepsis research.
Keywords:
CoagulationContact systemMicrovesiclesPneumolysin

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