Interactions between platelets, leukocytes, and the endothelium

While it is well established that platelets are integral to hemostasis, more recent evidence points to additionally important roles for platelets in inflammation and the immune response, owing partially to their rapid appearance at sites of injury and infection. Through direct cell contact, platelets can alter the properties of endothelial cells and leukocytes. Additionally, platelet degranulation releases effectors that can act locally on endothelial cells and leukocytes, and that can potentially alter endothelial function and the systemic inflammatory milieu. This chapter reviews the mediators of platelet-leukocyte and platelet-endothelial interactions, their functional consequences, and their roles in disease.