CELL SURFACE PROTEINS INVOLVED IN ECHOVIRUS ATTACHMENT

埃可病毒是人类小核糖核酸病毒，其负责许多 临床综合征，包括新生儿的致命性播散性感染， 免疫功能低下的宿主以及发烧和正常宿主的皮疹。 埃可病毒的32种血清型是脑膜炎的主要病因 在美国 病毒受体是细胞表面蛋白，其允许病毒结合至 宿主细胞是病毒在哺乳动物细胞中复制的初始步骤。 这些蛋白质通常直接负责蛋白质的向性。 病毒和病毒受体cDNA的转染可以赋予易感性 这些细胞以前不容易感染。 我们有 先前定义的VLA/2（α 2 β 1整联蛋白）作为 埃可病毒1和8。 利用鼠-人嵌合蛋白， 能够在VLA/2上定位埃可病毒结合位点。 我们最近的数据 表明VLA/2 α链的I区能够 结合埃可病毒并赋予非埃可病毒感染易感性， 允许细胞 在这个提议中，我们计划将埃可病毒1型的结合位点定位在 所述氨基酸水平和制备分离的I区蛋白以允许 病毒宿主相互作用的详细研究， 使病毒和宿主受体分子结晶。 另外，我们现在发现糖基磷脂酰肌醇 (GPI)补体调节蛋白衰变加速因子 是许多其他埃可病毒的受体。 这种蛋白质， 由连接到GPI尾的4个短的共有重复序列组成， 在内皮细胞和上皮细胞表面高度表达。 它以多种可溶性和膜锚定形式存在于人体中。 我们计划定义的binding网站和调查的作用，这是 蛋白质具有病毒向性和感染性。 我们将使用双转染子评估GPI尾在病毒感染中的作用。 进入和复制。 最后，我们的数据表明， 埃可病毒与一种尚未确定的蛋白质结合。 因此，我们计划 通过定义受体来完成我们对埃可病毒的分组， 剩下的病毒开始了解埃可病毒的嗜性， 发病机制

Echoviruses are human picornaviruses which are responsible for a number of clinical syndromes including fatal disseminated infections in neonates and immunocompromised hosts as well as fever, and skin rashes in normal hosts. As a group the 32 serotypes of echovirus are the major cause of meningitis in the United States. Virus receptors are cell surface proteins which allow for virus binding to the host cell, the initial step in viral replication in mammalian cells. These proteins are often directly responsible for the tropism of the virus, and transfection of viral receptor cDNA can confer susceptibility upon cells which were not previously susceptible to infection. We have previously defined VLA/2 (an alpha2 beta1 integrin) as the receptor for echoviruses 1 and 8. Utilizing mouse-human chimeric proteins we have been able to map the echovirus binding site on VLA/2. Our recent data indicates that the I region of the alpha chain of VLA/2 is capable of binding echovirus and conferring susceptibility to infection to non- permissive cells. In this proposal we plan to map the binding site for echovirus type 1 at the amino acid level and prepare isolated I region protein to allow a detailed study of the virus host interaction with the long term goal of crystallizing both the virus and host receptor molecules. In addition we have now found that the glycosyl phosphatidyl inositol (GPI) linked complement regulatory protein Decay Accelerating Factor (DAF) is the receptor for a number of other echoviruses. This protein, which is composed of 4 short consensus repeat sequences attached to a GPI tail is highly expressed on the surface of endothelial cells and epithelial cells. It exists in a variety of soluble and membrane anchored forms in humans. We plan to define the DAF binding sites and investigate the role that this protein has in viral tropism and infectivity. Using DAF transfectants we will assess the role of the GPI tail in viral entry and replication. Finally our data indicate that several other echoviruses bind to an as yet undefined protein(s). Therefore we plan to finish our grouping of the echoviruses by defining the receptors for the remaining viruses to begin to understand echovirus tropism and pathogenesis.