Developing Cathepsin Inhibitors as Therapeutics for Emerging Viral Infections

摘要 对于许多新出现的病毒，迫切需要有效的补救措施。能够抑制多种新出现的病毒的治疗方法将是理想的。最近的证据表明，细胞组织蛋白L和B在高致病性病毒埃博拉、尼帕希亨德拉和SARS冠状病毒的病毒糖蛋白加工和细胞进入过程中起着至关重要的作用。对于埃博拉和SARS冠状病毒，细胞组织酶抑制剂有效地阻止病毒在细胞培养中的进入和复制。相反，通过药理学或遗传学方法抑制细胞组织蛋白酶功能 方法，在小鼠中耐受性良好，强烈表明这些酶是抗病毒药物开发的良好靶点。这项提议将测试通过生化高通量筛选确定的化合物，以对抗人类组织蛋白酶B和L，它们是使用逆转录病毒假型进入埃博拉病毒的抑制剂。一种新的丝状病毒 将使用粒子系统来确认先导化合物阻止埃博拉感染的能力。最后，有希望的候选人将接受对抗“活的”埃博拉感染的有效性测试。鉴于埃博拉、Nipahhendra和SARS病毒都需要细胞组织蛋白，这些研究将确定开发新的先导化合物 治疗对多种新出现的病毒威胁有效。为了实现这一目标，我们提出了以下目标：具体目标1)利用基于生化的高通量不同文库的筛选来鉴定组织蛋白酶B和组织蛋白酶L抑制剂。进行结构活性分析以提高疗效并改变已识别的 CATL抑制剂。具体目的2)用假型、丝状病毒样颗粒和活的埃博拉病毒检测候选组织蛋白酶B和L抑制剂化合物的病毒侵入抑制作用。

Abstract There is an urgent need for effective remedies for many newly emergent viruses. Therapeutics capable of inhibiting multiple emerging viruses would be ideal. Recent evidence demonstrates an essential role for cellular cathepsins L and B in viral glycoprotein processing and cellular entry for the highly pathogenic viruses Ebola, NipahIHendra and SARS Coronavirus. For Ebola and SARS CoV, inhibitors of the cellular cathepsin enzymes effectively block viral entry and replication in cell culture. In contrast, inhibition of cellular cathepsin function, by either by pharmacologic or genetic methods, is well tolerated in mice strongly suggesting that these enzymes are good targets for antiviral drug development. This proposal will test compounds identified through a biochemical high throughput screen against human cathepsins B and L as inhibitors of Ebola virus entry using retroviral pseudotypes. A novel filamentous viruslike particle system will be employed to confirm the ability of lead compounds to block Ebola infection. Finally, promising candidates will be tested for efficacy against "live" Ebola infection. Given that Ebola, NipahIHendra and SARS viruses all require the cellular cathepsins, these studies will identify new lead compounds for development of therapeutics effective for multiple emerging viral threats. To accomplish this goal we propose the following aims: Specific Aim 1) Utilize a biochemical-based high throughput screen of diverse libraries to identify cathepsin B and Cathepsin L inhibitors. Perform structure activity analysis to improve efficacy and alter the specificity of an identified CatL inhibitor. Specific Aim 2) Test the candidate cathepsin B and L inhibitor compounds for inhibition of viral entry using pseudotype, filamentous virus-like particle and "live" Ebola assays.