Structural Determinants of Human Antibodies neutralizing the Ebola Virus

总结 丝状病毒家族包括马尔堡病毒和埃博拉病毒，其中大多数引起高度致命的出血性 发烧1967年，第一种丝状病毒在欧洲的实验室工作人员中被发现。从那以后，费罗- 病毒已经多次重新出现，现代病毒株具有更大的致死性（~90%）。埃博拉病毒是 通常在中非发现，但2014年在西非重新出现，导致持续爆发， 在规模和地理范围上都是史无前例的，已经夺去了成千上万人的生命。 乌干达目前也爆发了马尔堡病毒。 上个月，几种中和抗体（Abs）与病毒靶蛋白复合的结构数据显示， 斜坡表面糖蛋白（GP）对我们来说是可用的，这是第一次使研究提出内 这个PAPID提案。具体地，一种Ab分别与马尔堡和埃博拉GP的共晶体结构， 以及另外六种抗体的电子显微镜（EM）密度图。我们的目标是调查 中和丝状病毒的人Ab的结构决定簇。虽然本研究的重点是 在对埃博拉病毒和马尔堡病毒感染的免疫反应的生物学问题上， 促进他人制定治疗策略的潜力。 在这个R21建议的范围内，我们追求三个目标：目标1创建原子细节模型， Ab/GP接口，用于所有七个Ab，并提供EM密度图。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， 抗体为了中和而需要满足的关键结构决定因素。目标2将从这些抗体中鉴定新的抗体。 可能用有限的一组穆塔中和埃博拉和/或马尔堡病毒的幼稚受试者库- 选择。我们还将比较丝状病毒初治（即先前未感染）人与未感染人的Ab库。 免疫（以前感染）受试者提供给我们。这些来自幼稚受试者的Abs很重要，因为它们 在感染或接种疫苗后可演变为中和抗体。我们将通过计算重新设计这些Abs， 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库， 一个成功的疫苗接种策略。在目标3中，我们将通过实验表征这些Ab的结合， 中和活性虽然最终这些Ab中最有前途的结构表征是 但这并不属于R21计划的范围。

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.