JLE

Hématologie

MENU

Platelet role in infection Volume 10, issue 3, Mai-Juin

Figures

See all figures

Authors
Service d’hématologie et d’immunologie, hôpital Ambroise‐Paré, Boulogne et faculté Paris‐Île de France‐Ouest. Département d’hématologie, Institut Cochin, Paris.

Previous platelet studies have mainly focused on their role in haemostasis and thrombosis and have only rarely emphasized their role during infection. In this review, we report the results of a study performed in order to examine platelet interaction with infectious microorganisms. Platelets were incubated in vitro with either bacteria (Staphylococcus aureus) or viral particles (HIV). Our results show that: ‐‐ platelets are able to endocytose infectious microorganisms; ‐‐ platelets activation increases the phenomenon; ‐‐ endocytosis of infectious microorganisms occurs in specific compartments of platelets. In particular, HIV viruses are endocytoses in small vesicles which resemble the phenomenon of macropinocytosis described in macrophages and dentritic cells; ‐‐ the content of α‐granules is secreted into the endocytic compartment and enters in contact with the engulfed microorganisms (virus or bacteria). In addition, a review of the literature concerning the anti‐infectious role of platelets has been made. The list of microbicidal proteins stored in the platelet granules clearly illustrates this function. Altough the role of platelet in infection has been firmly demonstrated by data from the literature and from our personal work, it remains ambivalent as platelets can contribute to host defense against infection as well as infection dissemination.