title: Platelets promote bacterial dissemination in a mouse model of streptococcal sepsis.
abstract: Platelets have been reported to contribute to inflammation and inflammatory disorders. In the present study, we demonstrate that platelets contribute to the acute response to bacterial infection in a mouse model of invasive Streptococcus pyogenes infection. Thrombocytopenia occurred rapidly in infected animals and this was associated with platelet activation, formation of platelet-neutrophil complexes and neutrophil activation. In order to assess the role of platelets during infection, platelets were depleted prior to infection. Platelet-depleted animals had significantly decreased platelet-neutrophil complex formation and neutrophil activation in response to infection. Importantly, significantly fewer bacteria disseminated to the blood, lungs, and spleen of platelet-depleted animals. Platelet-depleted animals did not decrease as significantly in weight as the infected control animals. The results demonstrate a previously unappreciated role for platelets during the pathophysiological response to infection, whereby S. pyogenes bacteria bind to platelets and platelets facilitate bacterial dissemination.
authors.affiliation: Division of Infection Medicine, Department of Clinical Sciences, Lund University, SE-22184 Lund, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Kahn
authors.forename: Sinead
authors.initials: S
authors.lastname: Hurley
authors.forename: Oonagh
authors.initials: O
authors.lastname: Shannon
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D001792:Blood Platelets / Q000276:immunology* / Q000382:microbiology*; D004195:Disease Models, Animal; D005260:Female; D007113:Immunity, Innate; D051379:Mice; D008807:Mice, Inbred BALB C; D018375:Neutrophil Activation; D011008:Pneumococcal Infections / Q000276:immunology / Q000382:microbiology / Q000503:physiopathology*; D018805:Sepsis / Q000276:immunology / Q000382:microbiology / Q000503:physiopathology*; D013296:Streptococcus pneumoniae / Q000502:physiology*
keywords: Platelets; Sepsis; Streptococcus