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The role of platelet MyD88 in host response during gram-negative sepsis

S F de Stoppelaar1,2, T A M Claushuis1,2, M P B Jansen3

  • 1Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.

Journal of Thrombosis and Haemostasis : JTH
|July 17, 2015
PubMed
Abstract

Insights

Platelet myeloid differentiation factor 88 (MyD88) does not influence bacterial growth or sepsis outcomes in gram-negative infections. This study found no significant role for platelet MyD88 in host defense or organ damage during sepsis.

Area of Science:

  • Immunology
  • Hematology
  • Microbiology

Background:

  • Platelets act as sentinel cells in host defense and contribute to both beneficial and detrimental responses during sepsis.
  • Myeloid differentiation factor 88 (MyD88) is crucial for pathogen recognition and immune responses.
  • Platelets express functional Toll-like receptors and MyD88, influencing their response to bacterial stimuli.

Purpose of the Study:

  • To investigate the role of platelet MyD88 in gram-negative sepsis.
  • To assess the impact of platelet MyD88 on bacterial clearance and host response using Klebsiella pneumoniae infections.

Main Methods:

  • Generated platelet-specific Myd88 knockout mice by crossing conditional Myd88 flox mice with Cre recombinase expressing mice.
  • Utilized a reverse approach involving transfusion of wild-type platelets into full Myd88 knockout mice.
  • Infected mice intravenously and via airway with Klebsiella pneumoniae.

Main Results:

  • Platelet MyD88 did not affect bacterial growth or dissemination in either infection model.
  • No influence of platelet MyD88 was observed on thrombocytopenia, coagulation, endothelial activation, or distant organ injury.
  • Platelet MyD88 played no role in lung pathology during pneumonia-induced sepsis.

Conclusions:

  • Platelet MyD88-dependent Toll-like receptor signaling does not contribute to the host response in gram-negative sepsis.
  • The findings challenge existing literature on the role of platelet MyD88 in sepsis pathogenesis.
Keywords:
Toll-like receptorsmicemyeloid differentiation factor 88plateletspneumoniasepsis

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