Development of a Small Molecule Inhibitor for KSHV LANA

描述：该研究计划的目标是开发和表征潜伏的卡波西肉瘤相关疱疹病毒(KSHV)感染的新型小分子抑制剂。KSHV/人类疱疹病毒8型(HHV-8)是一种人类疱疹病毒，是卡波西肉瘤(Kaposi‘s Saroma’s，KS)的病原体。KS是一种淋巴管内皮细胞恶性肿瘤，在HIV-AIDS患者中最常见和最严重。KS影响了大约20%没有服用抗艾滋病毒药物的艾滋病毒阳性患者。此外，在艾滋病毒得到控制的患者中，似乎出现了新的KS病例增加。KSHV还与几种淋巴系统疾病有关，包括胸腔积液淋巴瘤和Castleman病。目前，尚无有效阻断KSHV感染或潜伏期的KSHV特异性治疗方法，因此仍不可能有效地治疗或预防KSHV相关的病理。潜伏感染和病毒致病需要一种病毒编码蛋白，潜伏相关核抗原(LANA)，它在潜伏期间作用于病毒基因组的复制和维持，并改变促进病毒和宿主细胞生存的细胞基因表达程序。LANA的遗传和生物破坏，包括siRNA耗尽和基因缺失，在潜伏感染期间阻止病毒基因组的持续。LANA DNA结合结构域(DBD)是抑制KSHV感染的理想小分子靶点。开发一种安全有效的LANA抑制剂将为KSHV相关恶性肿瘤的治疗提供重要的治疗策略。该计划建立在成功完成LANA小分子抑制剂高通量筛选的基础上，以及我们最近对LANA DNA结合域的X射线晶体结构的确定。我们开发针对EB病毒蛋白EBNA1的小分子抑制剂的经验进一步降低了该项目的风险，这些小分子抑制剂的结构和功能与LANA相似。我们使用高通量筛选、结晶学和基于结构的药物设计方法，将有效的HITS优化为对EBNA1具有中到低纳摩尔活性的先导化合物。在这份R01提案中，我们计划应用类似的策略来确定和优化用于治疗KSHV相关疾病的LANA抑制剂。

DESCRIPTION: The goal of this research program is to develop and characterize novel small molecule inhibitors of latent Kaposi's Sarcoma Associated Herpesvirus (KSHV) infection. KSHV/Human Herpes Virus 8 (HHV-8) is a human herpesvirus and the causative agent of Kaposi's sarcoma's (KS). KS is a lymphatic-endothelial cell malignancy that occurs most frequently and severely in patients with HIV-AIDS. KS affects about 20% of HIV- positive patients who are not taking anti-HIV drugs. In addition, there appears to be an increase of new cases of KS in patients whose HIV is under control. KSHV has also been implicated in several lymphoid disorders, including pleural effusion lymphoma and Castleman's disease. At present, there are no KSHV-specific therapies that effectively block KSHV infection or latency, and therefore it remains impossible to effectively treat or prevent KSHV-related pathologies. Latent infection and viral pathogenesis require one viral encoded protein, Latency-Associated Nuclear Antigen (LANA), which functions in the replication and maintenance of the viral genome during latency, and alters cellular gene expression programs that promote virus and host cell survival. Genetic and biological disruption of LANA, including siRNA depletion and gene deletion, block viral genome persistence during latent infection. The LANA DNA binding domain (DBD) has been characterized biochemically and structurally, and serves as an ideal target for small molecule inhibition of KSHV infection. The development of a safe and effective inhibitor of LANA would provide an important therapeutic strategy for the treatment of KSHV-associated malignancies. This program builds on the successful completion of a high- throughput screen for small molecule inhibitors of LANA, and on our recent determination of the X-ray crystal structure of the LANA DNA binding domain. The risk of this project is further mitigated by our experience developing small molecule inhibitors targeting Epstein-Barr Virus protein EBNA1 with similar structure and function as LANA. We have used high-throughput screening, crystallography, and structure-based drug design approaches to optimize validated hits into lead compounds that possess mid to low-nanomolar activity for EBNA1. In this R01 proposal, we plan to apply a similar strategy to identify and optimize LANA inhibitors for the treatment of KSHV-related disease.