A Cellular Receptor for New World Arenaviruses

描述（由申请人提供）：沙粒病毒引起人类严重的病毒性出血热。五种沙粒病毒由于其可能被误用和引起疾病的严重程度而被列为NIAID A类病原体：淋巴细胞性脉络丛脑膜炎（LCM）、拉沙病毒、瓜纳里托病毒、马丘波病毒和朱宁病毒。LCM病毒和拉沙病毒是使用细胞受体的旧大陆沙粒病毒？-三磷酸腺苷进入细胞。瓜纳里托病毒、马丘波病毒和朱宁病毒都是新世界出血热沙粒病毒，它们被认为使用一种共同的受体，但这种受体尚未被确定。在初步数据中，我们证明了转铁蛋白受体1 （Tfr1）与马丘波病毒的进入糖蛋白（GP）之间存在高度亲和的关联。人Tfr1显著提高了Machupo假病毒或Junin假病毒感染弱容纳性仓鼠细胞系的效率，而不是拉沙假病毒。进入人细胞系的马丘波假病毒（Machupo pseudovirus）可被抗人Tfr1抗体清除，而非拉沙假病毒（Lassa pseudovirus）。我们的数据表明Tfr1是新世界出血热沙粒病毒的专性细胞受体。我们的目标是：(1)充分表征Tfr1和Tfr2在广泛的沙粒病毒进入过程中的作用，(2)确定Tfr1和GP高亲和力关联的决定因素，(3)表征Tfr1物种变异在沙粒病毒进入过程中的作用，(4)描述可溶性Tfr1和各种抗Tfr1抗体在进入过程中的作用，(5)描述铁和Tfr1相关蛋白在沙粒病毒进入过程中的作用，(6)合作解决GP与Tfr1结合的结构。

DESCRIPTION (provided by applicant): Arenaviruses cause severe viral hemorrhagic fevers in humans. Five arenaviruses have been classified as NIAID Category A pathogens due to their potential for misuse and the severity of the disease they cause: lymphocytic choriomeningitis (LCM), Lassa, Guanarito, Machupo, and Junin viruses. LCM and Lassa viruses are Old World arenaviruses that use the cellular receptor ?-dystroglycan to enter cells. Guanarito, Machupo, and Junin viruses, all New World hemorrhagic fever arenaviruses, are thought to use a common receptor, but this receptor has not been identified. In preliminary data, we demonstrate a high affinity association between transferrin receptor 1 (Tfr1) and the entry glycoprotein (GP) of Machupo virus. Human Tfr1 markedly increased the efficiency with which Machupo or Junin pseudoviruses, but not Lassa pseudovirus, infected a weakly permissive hamster cell line. Entry into human cell lines of Machupo pseudovirus, but not Lassa pseudovirus, was abolished by anti-human Tfr1 antibody, but not by a control antibody. Our data indicate that Tfr1 is an obligate cellular receptor for New World hemorrhagic fever arenaviruses. Our aims are to: (1) fully characterize the role of Tfr1 and Tfr2 in the entry processes of an extensive panel of arenaviruses, (2) identify Tfr1 and GP determinants of their high affinity association, (3) characterize the role of Tfr1 species variation in arenaviral entry, (4) describe the effect of soluble Tfr1, and of various anti-Tfr1 antibodies on entry, (5) describe the role of iron and of Tfr1- associated proteins in arenaviral entry, (6) collaborate to solve the structure of GP bound to Tfr1. These studies will shed light on why some, but not all arenaviruses cause hemorrhagic fevers in humans, and will help assess the risk posed by those that have not infected humans. They will also contribute to the development of protein and small-molecule therapeutics for South American hemorrhagic fevers.