Pathogenic interaction of enterovirus 71 with PSGL-1 on human leukocytes

描述（由申请人提供）：肠道病毒71（EV 71）导致儿童手足口病（HFMD）。与只引起轻度手足口病的相关病毒不同，EV 71也会引起严重的神经系统疾病和死亡-最常见的原因是肺水肿和心肺功能衰竭。最近在亚洲发生的流行病影响了数百万儿童，给卫生保健系统带来沉重负担，并造成数千人死亡。为什么有些儿童患有严重的神经系统疾病或肺水肿尚不清楚，但肺水肿和致命的结果与高水平的炎性细胞因子有关。我们相信，一个关键因素可能是特异性EV 71分离株对P-选择素糖蛋白配体-1（PSGL-1）的嗜性，PSGL-1是一种几乎只在血细胞上表达的信号受体。 PSGL-1介导白细胞与血管壁上的选择素的束缚（6），并且PSGL-1参与启动一系列细胞内事件，其促进白细胞粘附粘附和迁移到组织中，并导致免疫细胞产生细胞因子和趋化因子。本申请的基本假设是病毒与白细胞上的PSGL-1相互作用在严重EV 71疾病的发病机制中是重要的，这既是因为它允许病毒进入并感染特定的白细胞群体，也是因为它触发PSGL-1介导的有助于白细胞活化、粘附/迁移和细胞因子产生的信号。 我们将测试这个 三组实验中的假设。首先，我们将鉴定以PSGL-1依赖性方式被EV 71结合或感染的白细胞亚群，并确定病毒结合或感染是否导致免疫细胞活化、粘附或细胞因子产生。其次，我们将确定EV 71与白细胞的相互作用是否刺激病毒和炎性细胞穿过血脑屏障的体外模型。最后，我们与上海巴斯德研究所的研究人员合作，通过检查从患有严重和轻度EV 71疾病的儿童中获得的病毒分离物，很好地确定PSGL-1结合病毒是否具有增加的致病潜力。

DESCRIPTION (provided by applicant): Enterovirus 71 (EV71) causes hand-foot-mouth disease (HFMD) in children. Unlike related viruses that cause only mild HFMD, EV71 also causes severe neurologic disease, and death- most often due to pulmonary edema and cardiorespiratory failure. Recent epidemics in Asia have affected millions of children, putting a heavy burden on the healthcare system, and causing thousands of deaths. Why some children suffer severe neurologic disease or pulmonary edema is not known, but pulmonary edema and fatal outcome are associated with high levels of inflammatory cytokines. We believe that one critical factor may be the tropism of specific EV71 isolates for P-selectin glycoprotein ligand-1 (PSGL-1), a signaling receptor almost exclusively expressed on blood cells. PSGL-1 mediates the tethering of leukocytes to selectins on vessel walls (6), and PSGL-1 engage- ment initiates a series of intracellular events that promote leukocyte adhesion adhesion and migration into tissues, and lead to the production of cytokines and chemokines by immune cells. The hypothesis underlying this application is that virus interaction with PSGL-1 on leukocytes is important in the pathogenesis of severe EV71 disease, both because it permits virus to enter and infect specific leukocyte populations, and because it triggers PSGL-1-mediated signals that contribute to leukocyte activation, adhesion/migration, and cytokine production. We will test this hypothesis in three sets of experiments. First, we will identify leukocyte subsets that are bound or infected by EV71 in a PSGL-1-dependent manner, and determine whether virus binding or infection leads to immune cell activation, adhesion, or cytokine production. Second, we will determine whether EV71 interaction with leukocytes stimulates the passage of virus and inflammatory cells across an in vitro model of the blood-brain barrier. Finally, in collaboration with investigators at the Pasteur institute of Shanghai, we well determine whether PSGL-1-binding viruses have increased pathogenic potential, by examining virus isolates obtained from children with severe and mild EV71 disease.