Structural Determinants of Human Antibodies neutralizing the Ebola Virus

摘要 丝状病毒家族包括马尔堡病毒和埃博拉病毒，其中大多数会导致高度致命的出血。 发烧。1967年，第一种丝状病毒被发现，当时它使欧洲的实验室工作人员患病。从那时起，费罗- 病毒多次卷土重来，现代毒株的致死率更高(~90%)。埃博拉病毒是 通常在中非发现，但于2014年在西非重新出现，导致持续的疫情 在规模和地理传播方面都是史无前例的，已经夺走了数千人的生命。 乌干达目前也爆发了马尔堡病毒。 上个月关于几种中和抗体(Abs)与病毒靶标ENVE-1的复合体的结构数据- Lope表面糖蛋白(GP)对我们来说是可用的，这是第一次在 这份PAPID提案。具体地说，一种抗体分别与马尔堡和埃博拉GP的共晶结构， 以及另外六个抗体的电子显微镜(EM)密度图。我们的目标是调查共享的 中和丝状病毒的人抗体的结构决定因素。虽然本研究因此将重点放在 关于对埃博拉和马尔堡病毒感染的免疫反应的生物学问题，它有 促进其他人制定治疗策略的潜力。 在此R21提案的范围内，我们追求三个目标：目标1创建 具有可用的电磁密度图的所有七个抗体的AB/GP接口。我们将使用共晶结构来测试 我们的计算协议，然后将其应用于其余六种情况。因此，我们将获得一张地图 抗体中和所需满足的关键结构决定因素。目标2将从新的抗体中识别出 一系列天真的主题，可能会用有限的一组突变- 特兹。我们还将比较丝状病毒-幼稚(即以前没有感染过)人类的抗体谱系 免疫(以前感染过的)对象对我们可用。这些来自幼稚对象的抗体很重要，因为它们 可在感染或接种疫苗后演变为中和抗体。我们将通过计算重新设计这些抗体以 结合和中和埃博拉和/或马尔堡病毒，以增加已知的中和抗体池，为 成功的疫苗接种策略的方法。在目标3中，我们将通过实验表征这些抗体的结合和 中和活性。虽然归根结底，这些抗体中最有希望的结构特征是 计划中的，它不在R21提案的范围内。

SUMMARY The filovirus family includes Marburg and Ebola viruses, most of which cause highly lethal hemorrhagic fever. The first filovirus was identified when it sickened laboratory workers in Europe in 1967. Since then, filo- viruses have re-emerged multiple times, with modern strains conferring greater lethality (~90%). Ebola virus is typically found in Central Africa, but re-emerged in Western Africa in 2014 to cause an on-going outbreak un- precedented in magnitude and geographic spread that has already claimed the lives of thousands of people. There is also a current outbreak of Marburg virus in Uganda. Last month structural data on several neutralizing antibodies (Abs) in complex with the viral target enve- lope surface glycoprotein (GP) became available to us, enabling for the first time the research proposed within this PAPID proposal. Specifically, co-crystal structures of one Ab with the Marburg and Ebola GP, respectively, as well as electron microscopy (EM) density maps for six additional Abs. It is our Goal to investigate the shared structural determinants of human Abs neutralizing the filovirus. While the present study thereby focuses on the biological question of the immune response to an infection by the Ebola and Marburg viruses, it has the potential to facilitate development of therapeutic strategies by others. Within the scope of this R21 proposal we pursue three goals: Aim 1 creates atomic detail models of the Ab/GP interface for all seven Abs with available EM density maps. We will use the co-crystal structure to test our computational protocol, and then apply it to the remaining six cases. As a result, we will obtain a map of critical structural determinants an Ab needs to fulfill for being neutralizing. Aim 2 will identify novel Abs from the repertoire of naïve subjects that are likely to neutralize Ebola and/or Marburg viruses with a limited set of muta- tions. We also will compare the Ab repertoires of filovirus-naïve (i.e. not previously infected) humans to those of immune (previously infected) subjects available to us. These Abs from naïve subjects are important, as they could evolve into neutralizing Abs upon infection or vaccination. We will redesign these Abs computationally to bind and neutralize Ebola and/or Marburg viruses, to increase the pool of known neutralizing Abs, paving the way for a successful vaccination strategy. In Aim 3 we will characterize these Abs experimentally for binding and neutralization activity. While ultimately a structural characterization of the most promising of these Abs is planned, it is outside the scope of the R21 proposal.