Therapeutics targeting cathepsin-activated viral entry

描述（由申请人提供）：最近的证据表明，细胞组织蛋白酶在病毒糖蛋白加工和高致病性病毒埃博拉、SARS、冠状病毒和尼帕/亨德拉病毒的细胞进入中发挥重要作用。组织蛋白酶L似乎对SARS冠状病毒和尼帕病毒的糖蛋白激活很重要，而埃博拉病毒需要组织蛋白酶L和组织蛋白酶B才能进入。这些酶的抑制剂有效地阻断了病毒在细胞培养中的进入和复制。该提案将建立在这些新发现的基础上，并将开发组织蛋白酶抑制剂作为这些不同病毒制剂的治疗方法。为了实现这一目标，我们提出以下目标：具体目标1)利用高通量筛选不同文库来鉴定组织蛋白酶抑制剂。2)采用携带埃博拉病毒、SARS冠状病毒或亨德拉病毒糖蛋白的假病毒，采用快速、定量和安全的方法测试候选化合物抑制病毒进入。证实对SARS冠状病毒和一种模型冠状病毒小鼠肝炎病毒（MHV）复制的抑制作用。特异性目的3)利用SARS冠状病毒和MHV在动物模型系统中测试目的1和2中鉴定的组织蛋白酶抑制剂。总之，拟议的工作将产生治疗埃博拉病毒、SARS冠状病毒和亨德拉病毒等病毒感染的候选分子。

DESCRIPTION (provided by applicant): Recent evidence demonstrates an essential role for cellular cathepsins in viral glycoprotein processing and cellular entry for the highly pathogenic viruses Ebola, SARS, coronavirus and Nipah/Hendra. Cathepsin L appears to be important for SARS CoV and Nipah virus glycoprotein activation while Ebola requires both cathepsins L and B for viral entry. Inhibitors of these enzymes effectively block viral entry and replication in cell culture. This proposal will build upon these new findings and will develop cathepsin inhibitors as therapeutics for these diverse viral agents. To accomplish this goal we propose the following aims: Specific Aim 1) Utilize high throughput screening of diverse libraries to identify cathepsin inhibitors. Specific Aim 2) Test the candidate compounds for inhibition of viral entry using a rapid, quantitative and safe assay employing viral pseudotypes carrying the glycoproteins of Ebola, SARS CoV, or Hendra virus. Confirm the inhibitory effect on replication of SARS CoV and a model coronavirus, mouse hepatitis virus (MHV). Specific Aim 3) Test the cathepsin inhibitors identified in Aims 1 and 2 in animal model systems using SARS CoV and MHV. In conclusion, the proposed work will produce candidate molecules for treatment of infection by viruses such as Ebola, SARS CoV and Hendra.