Therapeutics targeting cathepsin-activated viral entry

描述（由申请人提供）：最近的证据表明，细胞组织蛋白酶在高致病性病毒埃博拉病毒、SARS病毒、冠状病毒和尼帕病毒/亨德拉病毒的病毒糖蛋白加工和细胞进入中具有重要作用。组织蛋白酶L似乎对SARS CoV和尼帕病毒糖蛋白活化很重要，而埃博拉病毒需要组织蛋白酶L和B两者才能进入。这些酶的抑制剂有效地阻断病毒进入细胞培养物和复制。这项提案将建立在这些新的发现，并将开发组织蛋白酶抑制剂作为治疗这些不同的病毒剂。为了实现这一目标，我们提出了以下目标：具体目标1）利用不同文库的高通量筛选来鉴定组织蛋白酶抑制剂。具体目的2）使用快速、定量和安全的测定法测试候选化合物对病毒进入的抑制作用，所述测定法采用携带埃博拉病毒、SARS CoV或亨德拉病毒的糖蛋白的病毒假型。确认对SARS CoV和模型冠状病毒小鼠肝炎病毒（MHV）复制的抑制作用。3）在动物模型系统中使用SARS CoV和MHV测试目的1和2中鉴定的组织蛋白酶抑制剂。总之，拟议的工作将产生候选分子，用于治疗埃博拉病毒，SARS CoV和Hendra等病毒感染。

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.