Structure-guided development of chemical inhibitors against Kaposi’s sarcoma-associated herpesvirus (KSHV)

针对卡波西肉瘤相关疱疹病毒 (KSHV) 的化学抑制剂的结构引导开发

基本信息

批准号：
9791594
负责人：
REN SUN
金额：
$ 20.36万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-03-01 至 2021-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9791594
关键词：
Acquired Immunodeficiency Syndrome Adverse effects Affinity Antiviral Agents Atmosphere Binding Binding Sites Biological Assay Capsid Capsid Proteins Cell Proliferation Cells Chemicals Complement Cryoelectron Microscopy DNA DNA biosynthesis Development Disease Docking Dose Drug Targeting Drug resistance Electrons Epstein-Barr Virus Infections Etiology Evaluation Family Fluorescence Future Genome Goals HIV Hairy Leukoplakia Herpesviridae Herpesviridae Infections Human Human Herpesvirus 4 Human Herpesvirus 8 Hydrophobicity In Vitro Infection Infectious Mononucleosis Inflammatory Interruption Kaposi Sarcoma Lead Life Life Cycle Stages Link Lymphoproliferative Disorders Lytic Phase Malignant Neoplasms Methods Modification Molecular Multicentric Angiofollicular Lymphoid Hyperplasia Mutagenesis Nasopharynx Carcinoma Nucleic Acids Patients Peptides Pharmaceutical Preparations Phase Process Production Property Proteins Public Health Reproducibility Research Resistance Resolution Risk Signal Transduction Site Structure Symptoms Syndrome Testing Toxic effect Viral Load result Virion Virus Virus Latency angiogenesis antiretroviral therapy base cytokine cytotoxicity druggable target ds-DNA fighting gammaherpesvirus high throughput screening improved in vivo inhibitor/antagonist latent infection lytic replication member mortality mutant novel nucleic acid analog post-transplant pressure prevent primary effusion lymphoma protein crosslink side effect small molecule libraries tool tumor tumorigenesis viral DNA

项目摘要

PROJECT SUMMARY Kaposi's sarcoma-associated herpesvirus (KSHV), a member of the gamma-herpesvirus subfamily, has been shown to be an etiologic agent of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. Kaposi's sarcoma is the most common malignancy associated with infection of human immunodeficiency virus (HIV) and develops in about 20% of acquired immunodeficiency syndrome (AIDS) patients without antiretroviral therapy. Viral latency of KSHV is thought to be directly linked to tumorigenesis, but viral lytic replication also contributes to tumorigenesis, directly and indirectly. Therefore, it is important to develop specific lytic replication inhibitors to control KSHV-associated cancers. Currently, the majority of the available drugs fighting herpesvirus infection are nucleic acid analogues targeting viral DNA synthesis. However, these nucleic acid drugs show extensive adverse effects including the frequent induction of drug resistant mutant viruses and various kinds of toxicity. Moreover, no drugs specifically targeting KSHV infection is available. Therefore, there is a need for the development of anti-KSHV drugs. We believe that aside from viral DNA synthesis, virus capsid assembly, which is a critical step for the production of progeny virions, can serve as a novel and potent drug target. KSHV capsids contain 955 capsid subunits. These subunits form a pressure-resistant network to withhold tens of atmospheres of pressure generated by its condensed ~150-kb dsDNA genome. We hypothesize that if an inhibitor binds to any one of the 955 capsid units, it will either prevent the formation of the capsid or result in an unstable capsid which bursts under the high pressure. The key point is that only one of the 955 units has to be targeted, thereby reducing the drug-to-target ratio by about a thousand-fold. Potentially, this method can reduce a drug's dose by ~ 3-Log, significantly minimizing its possible toxicity and side effects. In other words, the high internal pressure and large number of subunits make herpesvirus capsid assembly prone to interruption and can therefore be targeted for the structure-guided development of antiviral agents. Recently, we resolved the atomic-resolution structure of the KSHV capsid by employing electron-counting cryo- electron microscopy (cryoEM). Guided by the cryoEM structure and functional analysis results, we identified a promising druggable site, which is a hydrophobic groove on the upper-domain of Major Capsid Protein (MCP). The objective of this R21 application is to identify chemical inhibitors targeting this druggable site with the following specific aims: 1) to identify chemical inhibitors by two complementary high-throughput screenings, and 2) to identify lead compounds by functional evaluation. The lead compounds, which interrupt herpesvirus capsid assembly, will not only be a useful tool for scientific research but also have the potential to be the first- in-class drugs against herpesvirus infection.

项目概要卡波西肉瘤相关疱疹病毒 (KSHV) 是 γ 疱疹病毒亚科的成员，已被被证明是卡波西肉瘤、原发性渗出性淋巴瘤和多中心卡斯尔曼氏病的病因疾病。卡波西肉瘤是与人类感染相关的最常见的恶性肿瘤免疫缺陷病毒 (HIV)，约 20% 的获得性免疫缺陷综合症 (艾滋病) 患者会出现这种情况未接受抗逆转录病毒治疗的患者。 KSHV 的病毒潜伏期被认为与肿瘤发生直接相关，但病毒裂解复制也直接或间接地促进肿瘤发生。因此，重要的是开发特异性裂解复制抑制剂来控制 KSHV 相关癌症。目前，大多数对抗疱疹病毒感染的现有药物是针对病毒 DNA 合成的核酸类似物。然而，这些核酸药物表现出广泛的副作用，包括频繁的药物诱导抗性突变病毒和各种毒性。此外，尚无专门针对 KSHV 感染的药物可用。因此，需要开发抗KSHV药物。我们相信除了病毒DNA合成、病毒衣壳组装是产生子代病毒颗粒的关键步骤，作为一种新颖且有效的药物靶点。 KSHV 衣壳含有 955 个衣壳亚基。这些亚基形成耐压网络可承受其冷凝 ~150-kb 产生的数十个大气压双链 DNA 基因组。我们假设，如果一种抑制剂与 955 个衣壳单元中的任何一个结合，它要么阻止衣壳的形成或导致不稳定的衣壳在高压下破裂。这关键在于，955个单位中仅需靶向一个，从而将药物与靶标的比例降低约一千倍。这种方法有可能将药物剂量减少约 3 个对数，从而显着减少药物剂量可能的毒性和副作用。换句话说，高内压和大量亚基使得疱疹病毒衣壳组装容易中断，因此可以针对结构引导抗病毒药物的开发。最近，我们通过采用电子计数冷冻技术解析了 KSHV 衣壳的原子分辨率结构电子显微镜（冷冻电镜）。在冷冻电镜结构和功能分析结果的指导下，我们确定了有前途的可成药位点，它是主要衣壳蛋白（MCP）上部结构域的疏水沟。该 R21 应用的目的是识别针对该可成药位点的化学抑制剂以下具体目标：1）通过两个互补的高通量筛选来识别化学抑制剂， 2) 通过功能评估来鉴定先导化合物。阻断疱疹病毒的先导化合物衣壳组装不仅将成为科学研究的有用工具，而且有可能成为第一个抗疱疹病毒感染的同类药物。