Antiviral Agents as Therapy for SARS

严重急性呼吸道综合征（SARS）是一种高度传染性的呼吸道疾病， 人冠状病毒（CoV），命名为SARS-CoV。虽然没有新的外地病例报告， 自2003年以来，该病毒继续在自然界中存在，构成了其回归的威胁。迄今为止， 目前尚无有效的抗SARS药物， 治疗和疫苗势在必行。本申请的主要目的是建立有效的抗病毒药物 预防未来SARS爆发的治疗方法。动物模型对于临床前安全性评价至关重要， 免疫原性和候选抗病毒药物和疫苗的功效。建立经济动物 在SARS-CoV感染的模型中，我们产生了表达人血管紧张素Ⅱ的转基因小鼠谱系， 转化酶2（hACE 2）是SARS冠状病毒的功能性受体。重要的是，这些hACE 2转基因 谱系对SARS-CoV感染高度敏感，表现出一致的临床表现， 死亡，使他们上级现有的模型描述的SARS（即，非人类灵长类动物，雪貂， 仓鼠和小鼠）。在几个转基因谱系中，AC 70谱系是最好的特征， 就SARS-CoV的感染性和组织、临床表现、组织病理学、炎性 反应和死亡率。为了实现这一目标，我在本申请中提出 为了评价一些抗病毒剂，包括干扰素（即，IFN-α和IFN-γ）， 利巴韦林和免疫血浆，在这个创新的和高度敏感的转基因小鼠模型。这些 选择抗病毒药物是因为它们在治疗SARS患者时是凭经验使用的， 在2002-2003年爆发性疫情期间，它们单独或联合使用的抗SARS功效 在这些转基因动物中，将以高度随机化和对照的方式仔细评估组合。 小鼠，使用临床、病毒学、病理学和炎症变化，沿着死亡率作为标准。如果 适用，我将扩大这一项目，包括新的先导化合物，如蛋白酶抑制剂，化合物 防止病毒进入，针对SARS-CoV复制的siRNA，以及保证包括在本研究中的疫苗。 提出了四个具体目标：1）确定选定的抗病毒药物的无毒剂量， 对SARS-CoV感染的治疗效果。2)确定最佳治疗方案 个体抗病毒剂的方案。3)评价免疫血浆/血清对以下疾病的治疗效果： SARS-CoV感染和4）研究选择的联合治疗的治疗潜力 抗病毒剂。在完成拟议的研究后，通过密切和富有成效的导师-学员互动， 预期不仅获得广泛的科学知识和抗病毒测试的实践经验， 以及找出有效抗SARS疗法的研究结果。

Severe acute respiratory syndrome (SARS) is a highly contagious respiratory disease caused by a novel human coronavirus (CoV), designated SARS-CoV. Although there have been no new reported field cases since 2003, this virus continues to exist in the nature, posing a threat for its return. To date, effective therapeutic measures against SARS are not available, thus making the development of effective antiviral therapy and vaccines imperative. The main objective of this application is to establish effective antiviral therapy against future SARS outbreaks. Animal models are critical for preclinical evaluation of the safety, immunogenicity, and efficacy of candidate antiviral drugs and vaccines. To establish an economical animal model for SARS-CoV infection, we generated transgenic mouse lineages expressing human angiotensin converting enzyme 2 (hACE2), a functional receptor of SARS-CoV. Importantly, these hACE2 transgenic lineages were highly susceptible to SARS-CoV infection, showing consistent clinical manifestations and death, making them superior to existing models described for SARS (i.e., nonhuman primates, ferrets, hamsters, and mice). Among several transgenic lineages, the AC70 lineage is the best characterized with regard to the infectivity and tissue of SARS-CoV, clinical manifestations, histopathology, inflammatory responses, and mortality, in response to infection. To accomplish this objective, I propose in this application to evaluate the therapeutic efficacy of some antiviral agents, including interferons (i.e., IFN-a and IFN-y), ribavirin, and immune plasma, in this innovative and highly sensitive transgenic mouse model. These antiviral agents are selected, because they were used empirically in treating SARS patients, resulting in anecdotal benefits during the explosive outbreak in 2002-2003. Their anti-SARS efficacy alone or in combination will be carefully assessed in a highly randomized and controlled fashion in these transgenic mice, using clinical, virological, pathological, and inflammatory changes, along with the mortality as criteria. If applicable, I will extend this project to include new lead compounds, such as protease inhibitors, compounds that prevent viral entry, siRNA for SARS-CoV replication, and vaccines that warrant inclusion in this study. Four specific aims are proposed: 1) Determine the nontoxic dosages of selected antiviral agents with therapeutic efficacy against SARS-CoV infection. 2) Determine the most optimal therapeutic treatment regimen of individual antiviral agents. 3) Evaluate the therapeutic efficacy of immune plasma/serum against SARS-CoV infection and 4) Investigate the therapeutic potentials of combination treatments of selected antiviral agents. Upon completion of proposed studies, with close and productive mentor-trainee interactions, anticipate not only gaining extensive scientific knowledge and hands-on experience in antiviral testing, but also research results identifying effective anti-SARS therapies.