Platelets are small anucleate cellular fragments that are released by megakaryocytes and safeguard vascular integrity through a process termed ‘haemostasis’. However, platelets have important roles beyond haemostasis as they contribute to the initiation and coordination of intravascular immune responses. They continuously monitor blood vessel integrity and tightly coordinate vascular trafficking and functions of multiple cell types. In this way platelets act as ‘patrolling officers of the vascular highway’ that help to establish effective immune responses to infections and cancer. Here we discuss the distinct biological features of platelets that allow them to shape immune responses to pathogens and tumour cells, highlighting the parallels between these responses.

血小板是由巨核细胞释放的小的无核细胞碎片，通过称为“止血”的过程来保护血管的完整性。然而，血小板具有止血以外的重要作用，因为它们有助于血管内免疫反应的启动和协调。他们持续监测血管完整性并紧密协调多种细胞类型的血管运输和功能。通过这种方式，血小板充当“血管高速公路的巡逻人员”，有助于建立对感染和癌症的有效免疫反应。在这里，我们讨论了血小板的独特生物学特征，这些特征使它们能够形成对病原体和肿瘤细胞的免疫反应，强调这些反应之间的相似之处。