Development of Host- Oriented Therapeutics Targeting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2),

这一I期申请的最终目标是发现和开发面向宿主的小分子化合物 针对严重急性呼吸系统综合征冠状病毒2型（SARS-CoV-2）感染。SARS-CoV-2是一种新型的 冠状病毒导致了目前严重呼吸综合征在人类中的全球大流行。抗病毒治疗剂 迫切需要对抗SARS-CoV-2和不断出现的新变种的感染。我们 已经发现了几个化学系列，目标是特定宿主蛋白质之间的模块化相互作用 含有NW结构域的病毒蛋白（例如Nedd 4）和含有PPxY基序的病毒蛋白（例如埃博拉病毒VP 40）。值得注意的是， 新出现的RNA病毒病原体如埃博拉病毒、马尔堡病毒、拉沙病毒和狂犬病病毒都编码PPxY基序， 招募宿主含有蛋白质的WWW结构域，以促进病毒的有效外出、扩散和传播。 有趣的是，SARS-CoV-2的表面暴露的刺突糖蛋白（S）也有一个假定的WW-domain 结合基序（25 PPAY 28），不存在于SARS-CoV-1或更弱的冠状病毒的S蛋白中 菌株在SARS-CoV-2病毒粒子的主要表面蛋白中获得这种PPAY基序，提高了SARS-CoV-2病毒粒子的免疫原性。 有趣的可能性，它可能有助于独特的致病性和/或传播的SARS-CoV-2通过 与特定宿主携带蛋白质的WW-domain相互作用。在我们正在进行的丝状病毒研究中， 我们已经使用广泛的SAR来识别能够阻断出口的先导化合物系列， 肝EBOV、MARV和LAFV在细胞培养物中传播，以及在肝中体内阻断疾病进展 MARV挑战模型。在这里，我们假设，“知情的”SAR分析，我们手头的PPxY/WWW域 抑制剂（例如先导候选物FC-10696）将导致发现能够阻断出口的类似物， SARS-CoV-2的疾病进展，以及未来可能出现的相关含PPxY的变体。 为了支持我们的假设，我们提出了强有力的初步数据表明，PPxY基序内的S蛋白 SARS-CoV-2病毒可以与宿主的含有蛋白质的WW-domain相互作用，这些蛋白质已知可以促进外出 EBOV、MARV和LAFV的传播。此外，我们目前的主要候选PPxY出芽抑制剂显示， 在人肺上皮细胞中阻断SARS-CoV-2病毒感染的活性。这项I期 我们将鉴定和评估作为SARS-CoV-2潜在治疗药物的宿主导向抑制剂， 相关的冠状病毒，结合科学家的制药和药物化学专业知识， 福克斯蔡斯化学多样性中心（FCCDC）凭借Harty Lab的专业知识和经验， 宾夕法尼亚大学在病毒-宿主相互作用和抗病毒治疗的实验方面， 德克萨斯生物医学研究所的Olena Shtanko实验室评估了抗活病毒的化合物 在BSL-3条件下。三个目标是（1）先导发现和优化药物化学，包括 ADME谱分析，（2）评价特异性抑制SARS-CoV-2 VLP和PPxY流出的能力， 介导的S-宿主蛋白相互作用，和（3）针对真实SARS-CoV-2病毒的体外和体内分析。

The ultimate goal of this Phase I application is to discover and develop host-oriented small molecule compounds targeting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. SARS-CoV-2 is a novel coronavirus driving the current global pandemic of severe respiratory syndrome in humans. Antiviral therapeutics are urgently needed to combat infection by SARS-CoV-2 and new variants that are continuing to emerge. We have discovered several chemical series that target modular interactions between specific host proteins containing WW-domains (e.g. Nedd4) and viral proteins containing PPxY motifs (e.g. Ebola VP40). Notably, emerging RNA virus pathogens such as Ebola, Marburg, Lassa, and rabies viruses all encode PPxY motifs that recruit host WW-domain containing proteins to facilitate efficient virus egress, spread, and transmission. Interestingly, the surface-exposed Spike glycoprotein (S) of SARS-CoV-2 also has a putative WW-domain binding motif (25PPAY28), that is not present in the S protein of SARS-CoV-1 or more attenuated coronavirus strains. The acquisition of this PPAY motif in the major surface protein of SARS-CoV-2 virions raises the intriguing possibility that it may contribute to the unique pathogenicity and/or transmission of SARS-CoV-2 via interactions with specific host WW-domain bearing proteins. In our ongoing studies on filoviruses and arenaviruses, we have used extensive SAR to identify a lead compound series capable of blocking egress and spread of live EBOV, MARV, and LAFV in cell culture, as well as blocking disease progression in vivo in a live MARV challenge model. Here, we hypothesize that “informed” SAR analyses of our in-hand PPxY/WW-domain inhibitors (e.g. lead candidate FC-10696) will lead to the discovery of analogs capable of blocking egress and disease progression of SARS-CoV-2, as well as related PPxY-containing variants that may emerge in the future. In support of our hypothesis, we present strong preliminary data showing that the PPxY motif within the S protein of SARS-CoV-2 virus can interact with host WW-domain containing proteins that are known to promote egress and spread of EBOV, MARV, and LAFV. Moreover, our current lead candidate PPxY budding inhibitors show activity in blocking egress of live SARS-CoV-2 virus infection in human lung epithelial cells. In this Phase I proposal, we will identify and evaluate host-oriented inhibitors as potential therapeutics for SARS-CoV-2 and related coronaviruses by combining the pharmaceutical and medicinal chemistry expertise of the scientists at the Fox Chase Chemical Diversity Center, Inc. (FCCDC) with the expertise and experience of the Harty Lab at the University of Pennsylvania in the experimental aspects of virus-host interactions and antiviral therapy, and the lab of Olena Shtanko at Texas Biomedical Research Institute for evaluating compounds against live viruses under BSL-3 conditions. The three aims are (1) lead finding and optimization medicinal chemistry including ADME profiling, (2) evaluation for the ability to specifically inhibit egress of SARS-CoV-2 VLPs and PPxY- mediated S-host protein interactions, and (3) in vitro and in vivo analyses against authentic SARS-CoV-2 virus.