Kazatchkine M D, Lambré C R, Kieffer N, Maillet F, Nurden A T
J Clin Invest. 1984 Sep;74(3):976-84. doi: 10.1172/JCI111518.
Influenza A virus-treated human platelets were lyzed in autologous serum. Lysis required the presence of antibody and occurred predominantly through activation of the classical complement pathway. Binding of the virus followed by its elution at 37 degrees C resulted in a dose-dependent desialation of the cells with a maximal release of 45% of total platelet sialic acid. In contrast, platelets that had been treated with Vibrio cholerae neuraminidase and from which 55% of total sialic acid had been removed were not lyzed in autologous serum and did not bind C3 as shown in binding assays using radiolabeled monoclonal anti-C3 antibody. Thus, the immune-mediated lysis of virus-treated platelets in autologous serum did not involve neoantigens expressed by desialated cells. To assess the effect of viruses on the platelet surface, treated platelets were incubated with galactose oxidase and sodium [3H]borohydride prior to separation and analysis of the labeled glycoproteins by SDS-PAGE. Viral treatment resulted in a desialation of each of the surface glycoproteins. At the same time, a labeled component of Mr 72,000 (nonreduced) and Mr 55,000 (reduced) was observed that was not present when V. cholerae-desialated platelets were examined in the same way. Immunoblotting experiments performed using antiwhole virus and anti-hemagglutinin antibodies demonstrated this component to be viral hemagglutinin. Involvement of membrane-bound hemagglutinin in antibody and in complement-mediated lysis of virus-treated platelets in autologous serum was supported by the increased lytic activity of a postvaccinal serum containing an elevated titer of complement fixing anti-hemagglutinin antibodies. Binding of a viral protein to the platelet surface provides a model for immune thrombocytopenias occurring during acute viral infections at the time of the specific immune response.
甲型流感病毒处理过的人血小板在自体血清中被裂解。裂解需要抗体的存在，并且主要通过经典补体途径的激活而发生。病毒结合后在37℃洗脱导致细胞的剂量依赖性去唾液酸化，总血小板唾液酸的最大释放量为45%。相比之下，用霍乱弧菌神经氨酸酶处理过且总唾液酸已去除55%的血小板在自体血清中未被裂解，并且在使用放射性标记的单克隆抗C3抗体的结合试验中未结合C3。因此，自体血清中病毒处理过的血小板的免疫介导裂解不涉及去唾液酸化细胞表达的新抗原。为了评估病毒对血小板表面的影响，在通过SDS-PAGE分离和分析标记糖蛋白之前，将处理过的血小板与半乳糖氧化酶和[3H]硼氢化钠一起孵育。病毒处理导致每种表面糖蛋白去唾液酸化。同时，观察到一个Mr为72,000（非还原）和Mr为55,000（还原）的标记成分，而以相同方式检查霍乱弧菌去唾液酸化血小板时该成分不存在。使用抗全病毒和抗血凝素抗体进行的免疫印迹实验表明该成分是病毒血凝素。含有补体固定抗血凝素抗体效价升高的疫苗接种后血清的裂解活性增加，支持了膜结合血凝素参与自体血清中病毒处理过的血小板的抗体和补体介导的裂解。病毒蛋白与血小板表面的结合为急性病毒感染期间特异性免疫反应时发生的免疫性血小板减少症提供了一个模型。
