Project 1 - Coronavirus

项目总结 人畜共患冠状病毒(CoV)如SARS-CoV和MERS-CoV是大流行的威胁。MERS-Cov 继续造成新的人畜共患传染病和人类传播和疾病，死亡率约为35%。目前，有以下几种 没有FDA批准的疗法来治疗任何冠状病毒。新的人畜共患病冠状病毒可能会从异种病毒中出现 动物水库中的水池，因此需要针对完全保守和脆弱的抗病毒策略 目标。COV快速选择对多类抑制剂的耐药性，表明需要 预防抗药性出现的方法。SARS和MERS感染都表现为严重 免疫病理损害，潜在地限制了直接作用抗病毒药物(DAA)的治疗窗口。 在没有抗病毒药物的情况下进行免疫调节已被证明是无益的，甚至会加剧 SARS和MERS病。因此，DAA和靶向免疫调节剂的组合可能是必要的 对已确定的感染进行有效治疗。我们计划的总体目标是开发冠状病毒抗病毒药物 广泛抑制已知和未来可能大流行的人畜共患病冠状病毒的战略，防止出现 通过靶向宿主免疫病理反应来延长治疗窗口。这个 拟议的研究将推进冠状病毒抑制核苷类似物EIDD的临床前开发。 1931/2801和其他核苷类似物正在进行中，并测试两个被确认为高度 积极抗击SARS冠状病毒，用于治疗和预防流行和紧急情况前的冠状病毒。在具体目标1中， 化合物的抗病毒活性和治疗效果的光谱将被定义。抗病毒的功效， 每种化合物的新陈代谢和细胞毒性将在原代人肺细胞培养中确定。 SARS冠状病毒和MERS冠状病毒的目标。铅化合物的预防和治疗效果将是 在青年、老年和免疫抑制的SARS和MERS发病机制的小鼠模型中进行评估。在……里面 具体目标2，将确定先导化合物的作用机制和耐药动力学。 将评估化合物在病毒复制、保真度和诱导先天免疫方面的抗病毒效果。 MERS-CoV和SARS-CoV在增强型病毒作用下传代的基因组耐药突变 药物的浓度将通过深度测序来确定。耐药性对SARS冠状病毒和MERS的影响- 将确定冠状病毒的毒力、对其他药物的敏感性以及先导化合物的治疗效果。 具体目标3将侧重于开发治疗新出现的柯萨奇病毒的联合疗法。这个 DAAs联合治疗SARS-CoV野毒株和耐药株感染的疗效 MERS冠状病毒将使用培养的细胞和小鼠进行定义。DAA联合治疗的疗效观察 将在SARS和MERS的小鼠模型中进行评估。这些研究将产生 IND备案和发起人类临床试验所需的机制和疗效数据。

PROJECT SUMMARY Zoonotic coronaviruses (CoVs) such as SARS-CoV and MERS-CoV are pandemic threats. MERS-CoV continues to cause new zoonotic and human transmission and illness with ~35% mortality. Currently, there are no FDA-approved therapies to treat any CoV. New zoonotic CoVs likely will emerge from heterogeneous virus pools in animal reservoirs, thus requiring antiviral strategies aimed at completely conserved and vulnerable targets. CoVs rapidly select for resistance to multiple classes of inhibitors, demonstrating the need for approaches to prevent resistance emergence. Both SARS and MERS infections manifest as severe immunopathologic damage, potentially limiting the therapeutic window for direct-acting antivirals (DAAs). Immunomodulation in the absence of antivirals has been shown to not be beneficial and to even exacerbate SARS and MERS disease. Thus, combinations of DAAs and targeted immunomodulators may be necessary for effective treatment of established infection. The overall goal of our program is to develop CoV antiviral strategies that broadly inhibit known and future potential pandemic zoonotic CoVs, prevent emergence of resistance, and extend the therapeutic window by targeting host immunopathologic responses. The proposed research will advance preclinical development of the CoV-inhibitory nucleoside analogue EIDD- 1931/2801 and other nucleoside analogues in the pipeline and test two small-molecule hits identified as highly active against SARS-CoV for treatment and prevention of epidemic and pre-emergent CoVs. In Specific Aim 1, the spectrum of antiviral activity and therapeutic efficacy of compounds will be defined. The antiviral efficacy, metabolism, and cytotoxicity of each compound will be determined in cultures of primary human lung cells targeted by SARS-CoV and MERS-CoV. The prophylactic and therapeutic efficacy of lead compounds will be evaluated in young, aged, and immunosuppressed murine models of SARS and MERS pathogenesis. In Specific Aim 2, the mechanism of action of lead compounds and kinetics of drug resistance will be determined. The antiviral effect of compounds on virus replication, fidelity, and induction of innate immunity will be assessed. Resistance mutations in genomes of MERS-CoV and SARS-CoV passaged in the presence of increasing concentrations of drug will be determined by deep sequencing. The impact of resistance on SARS-CoV and MERS- CoV virulence, sensitivity to other drugs, and therapeutic efficacy of lead compounds will be determined. Specific Aim 3 will focus on the development of combination regimens for the treatment of emerging CoVs. The combined therapeutic efficacy of DAAs against infections with both wild-type and drug-resistant SARS-CoV and MERS-CoV will be defined using cultured cells and mice. The therapeutic effect of treatment combining a DAA with an immunomodulator will be assessed in mouse models of SARS and MERS. These studies will generate mechanistic and efficacy data necessary for IND filing and origination of human clinical trials.