Exploiting Vulnerability on Influenza Virus

项目总结/摘要 甲型流感病毒表现出极大的多样性，例如血凝素（HA， H1-H18）和神经氨酸酶（NA，N1-N11）表面抗原。到目前为止，可能的198个中只有3个 禽和其他动物宿主中HA和NA的组合与人类大流行有关 (H1N1、H2N2、H3N2）。然而，对流感造成的大流行威胁的担忧日益加剧， 人畜共患病起源的病毒引起了人们对出现人传染病毒的高度关注， 可以使人类数量减少。最近出现的H5 N1、H6 N1、H7 N7、H7N9、H9 N2和 人类中的H10 N8病毒不断提醒人们这种可能性。流感B病毒及其 两种截然不同的谱系进一步增加了全球季节性流感的健康和经济负担。在这 建议，我们的目标是阐明，在结构层面上，对流感病毒的脆弱性的关键网站， 将抗体和受体类似物如何靶向这些位点的基本信息纳入结构中， 基于新疗法的设计、开发和合成。抗体介导的流感中和 病毒是人类免疫系统的复杂组合问题， 不断进化的病毒。虽然传统上针对人类流感的中和抗体 被认为是菌株特异性的，最近的进展表明，可以建立更广泛的反应 并为我们提供了宝贵的新的见解保守的网站的脆弱性。我们正在收集 有证据表明，可以对流感产生持续的、跨血清型的反应， 现在可以利用这些信息来设计小分子、肽和蛋白质， 易受感染的地点，从而阻止流感感染。目前没有有效的药物可用于 防止流感病毒进入。作为我们方法的概念验证，我们确定了晶体 与HA复合的umifenovir（在俄罗斯和中国使用的流感感染的抗病毒药）的结构， 利用这一结构信息合成了一种结合力提高100倍的衍生物。我们将阐明 识别大流行和新出现的流感病毒中这些脆弱位点的共同特征 从具有广泛中和抗体的不同HA的晶体结构以及作为模拟物的唾液酸苷， 天然受体的。一种结合生物物理、生物化学和化学的方法， 艺术结构生物学、酵母展示进化和化学生物学将被用来设计和合成 小分子作为控制和对抗未来流感威胁的新型治疗候选物 流行病和季节性流行病。

PROJECT SUMMARY / ABSTRACT Influenza A viruses exhibit extreme diversity as exemplified by the multiple serotypes of the hemagglutinin (HA, H1-H18) and neuraminidase (NA, N1-N11) surface antigens. To date, only three of the possible 198 combinations of HA and NA in avian and other animal reservoirs have been associated with human pandemics (H1N1, H2N2, H3N2). However, ever increasing anxiety about pandemic threats stemming from influenza viruses of zoonotic origins have heightened concern about emergence of a human transmissible virus that could devastate the human population. The recent appearance of H5N1, H6N1, H7N7, H7N9, H9N2, and H10N8 viruses in the human population are constant reminders of this possibility. Influenza B viruses with their two distinct lineages further increase the health and economic burden of seasonal influenza worldwide. In this proposal, we aim to elucidate, at the structural level, key sites of vulnerability on influenza virus and incorporate the essential information on how antibodies and receptor analogs target these sites into structure- based design, development, and synthesis of novel therapeutics. Antibody-mediated neutralization of influenza virus is a complex combinatorial problem for the human immune system when presented with diverse, highly variable and constantly evolving viruses. While neutralizing antibodies against human flu are traditionally regarded as being strain specific, recent advances have shown that much broader responses can be mounted and provided us with valuable new insights into conserved sites of vulnerability. We are amassing compelling evidence that a sustained, cross-serotype response can be mounted against influenza and this vital information can now be harnessed for design of small molecules, peptides, and proteins to target these key sites of vulnerability, thereby blocking influenza infection. No effective drugs are currently available for preventing entry of influenza virus. As a proof-of-concept of our approach, we have determined the crystal structure of umifenovir (an antiviral for influenza infection used in Russia and China) in complex with HA and exploited this structural information to synthesize a derivative with 100x improved binding. We will elucidate common features for recognition of these sites of vulnerability in pandemic and emerging influenza viruses from crystal structures of diverse HAs with broadly neutralizing antibodies as well as sialosides that are mimics of the natural receptor. A combined biophysical, biochemical, and chemical approach employing state-of-the- art structural biology, yeast-display evolution, and chemical biology will be harnessed to design and synthesize small molecules as novel therapeutic candidates to control and combat the threat of future influenza pandemics as well as seasonal epidemics.