Fusion Inhibitors of H5N1

新出现的禽流感病毒对家禽和人类健康构成越来越大的威胁。的 流感病毒血凝素（HA）是有吸引力药物靶标，因为它们对于病毒进入是必需的， 是病毒复制不可或缺的我们假设，目前正在开发的融合抑制剂，在这方面， 该计划将有效对抗各种病毒株，特别是高致病性禽流感病毒。进一步发展的具体目标 这些抑制剂是：Aim 1.鉴定对多种H5 N1流感病毒株有效的融合抑制剂 病毒我们的初步研究已经确定了一组先导化合物，其EC 50值在单个 在不同流感病毒株（包括H5 N3（疫苗株）、H3 N2、H1N1和 B。为了确定抗HPAI H5 N1病毒的临床前和最终临床研究的潜在候选物，我们 建议开发一个基于初始先导化合物的类似物库。我们建议测量抑制性 候选化合物针对不同H5 N1流感病毒株的效力。先导化合物 从这些研究中确定的药物将作为项目10的组成部分进入临床前研究。目标二。 确定HA蛋白抑制剂的作用机制。我们的初步数据表明， 我们开发的抑制剂改变了HA的结构。对于目标1中确定的有效化合物， 针对H5 N1病毒，我们将确定使用生物和生物化学方法阻断病毒进入的哪一步， 测定。为了绘制化合物的结合位点，我们将使HA蛋白与结合的抑制剂共结晶， 我们还将产生和鉴定耐药变异体。重组HA将用不同的 蛋白酶，以便映射构象敏感区域。目标3。确定药物组合， 包括HA抑制剂在内的药物在预防疾病方面优于现有的单一药物疗法 避免耐药性。HA抑制剂的广泛使用可能导致出现耐药性 病毒，类似于对神经氨酸酶（NA）观察到的获得耐药性 和M2抑制剂。我们假设HA抑制剂与现有NA和/或M2联合使用， 抗病毒剂有助对抗抗药性及减低传染病的严重程度。

Emerging avian influenza viruses pose an increasing threat to domestic poultry and human health. The influenza virus hemagglutinin (HA) is an attractive drug target because they are essential for viral entry, and indispensable for virus replication. We hypothesize that fusion inhibitors currently under development in this program will be potent against diverse virus strains, especially HPAI viruses. Specific aims to further develop these inhibitors are:Aim 1. Identify fusion inhibitors that are potent against diverse strains of H5N1 influenza viruses. Our preliminary studies have identified a group of lead compounds that have EC50 values in single digit nanomoles across diverse influenza virus strains including H5N3 (vaccine strain), H3N2, H1N1 and type B. To identify potential candidates for preclinical and eventual clinical studies against HPAI H5N1 viruses, we propose to develop a library of analogs based on the initial lead. We propose to measure the inhibitory potencies of candidate compounds against diverse strains of H5N1 influenza viruses. Lead compounds identified from these studies will be advanced to preclinical studies as a component of Program 10. Aim 2. Determine the mechanisms of action of HA protein inhibitors.Our preliminary data indicate that the fusion nhibitors we have developed alter the structure of HA. For compounds identified in Aim 1 that are potent against H5N1 viruses, we will determine which step of virus entry is blocked using biological and biochemical assays. To map the binding sites of compounds, we will co-crystallize the HA protein with bound inhibitor, and we will also generate and characterize resistant variants. Recombinant HA will be treated with different proteases in order to map the conformationally sensitive regions. Aim 3. Determine if drug combinations that nclude HA inhibitors provide advantages over existing single-agent therapies in protecting against disease and avoiding drug resistance. A widespread use of HA inhibitors could result in the emergence of drugesistant viruses, similar to the acquisition of drug resistance that has been observed for neuraminidase (NA) and M2 inhibitors. We hypothesize that the use of HA inhibitors in combination with existing NA and/or M2 nhibitors will help counteract drug resistance and decrease the severity of infectious disease.