Calvin Phoebe & Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada.
Int J Lab Hematol. 2013 Jun;35(3):254-61. doi: 10.1111/ijlh.12084.
Although the function of platelets in the maintenance of hemostasis has been studied in great detail, more recent evidence has highlighted a central role for platelets in the host inflammatory and immune responses. Platelets by virtue of their large numbers and their ability to rapidly release a broad spectrum of immunomodulatory cytokines, chemokines, and other mediators act as circulating sentinels. Upon detection of a pathogen, platelets quickly activate and begin to drive the ensuing inflammatory response. Platelets have the ability to directly modulate the activity of neutrophils (phagocytosis, oxidative burst), endothelium (adhesion molecule and chemokine expression), and lymphocytes. Due to their diverse array of adhesion molecules and preformed chemokines, platelets are able to adhere to leukocytes and facilitate their recruitment to sites of tissue damage or infection. Furthermore, platelets directly participate in the capture and sequestration of pathogens within the vasculature. Platelet-neutrophil interactions are known to induce the release of neutrophil extracellular traps (NETs) in response to either bacterial or viral infection, and platelets have been shown to internalize pathogens, sequestering them in engulfment vacuoles. Finally, emerging data indicate that platelets also participate in the host immune response by directly killing infected cells. This review will highlight the central role platelets play in the initiation and modulation of the host inflammatory and immune responses.
虽然血小板在止血中的作用已经被深入研究，但最近的证据强调了血小板在宿主炎症和免疫反应中的核心作用。由于血小板数量众多，并且能够迅速释放广泛的免疫调节细胞因子、趋化因子和其他介质，因此它们充当着循环哨兵。一旦检测到病原体，血小板就会迅速激活并开始驱动随后的炎症反应。血小板具有直接调节中性粒细胞（吞噬作用、氧化爆发）、内皮细胞（黏附分子和趋化因子表达）和淋巴细胞活性的能力。由于其多样化的黏附分子和预先形成的趋化因子，血小板能够黏附白细胞并促进它们向组织损伤或感染部位的募集。此外，血小板直接参与了在血管内捕获和隔离病原体的过程。已知血小板-中性粒细胞相互作用会诱导中性粒细胞细胞外陷阱（NETs）的释放，以响应细菌或病毒感染，并且已经表明血小板能够内化病原体，将其隔离在吞噬小泡中。最后，新出现的数据表明，血小板还通过直接杀死受感染的细胞来参与宿主的免疫反应。这篇综述将强调血小板在启动和调节宿主炎症和免疫反应中的核心作用。
