Development of a Small Molecule Inhibitor for KSHV LANA

产品说明：本研究计划的目标是开发和表征新型小分子抑制剂的潜伏性卡波西肉瘤相关疱疹病毒（KSHV）感染。KSHV/人类疱疹病毒8（HHV-8）是一种人类疱疹病毒，是卡波西肉瘤（KS）的病原体。KS是一种淋巴内皮细胞恶性肿瘤，在艾滋病毒/艾滋病患者中最常见且最严重。KS影响约20%的HIV阳性患者，他们没有服用抗HIV药物。此外，在艾滋病毒得到控制的患者中，新的KS病例似乎有所增加。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，还没有KSHV特异性疗法可以有效阻断KSHV感染或潜伏期，因此仍然不可能有效治疗或预防KSHV相关的病理。潜伏感染和病毒发病机制需要一种病毒编码的蛋白质，潜伏相关核抗原（拉娜），其在潜伏期期间在病毒基因组的复制和维持中起作用，并改变促进病毒和宿主细胞存活的细胞基因表达程序。拉娜的遗传和生物学破坏，包括siRNA缺失和基因缺失，在潜伏感染期间阻断病毒基因组持续存在。拉娜DNA结合结构域（DBD）已被生物化学和结构表征，并且作为小分子抑制KSHV感染的理想靶标。开发安全有效的拉娜抑制剂将为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拉娜小分子抑制剂的高通量筛选和我们最近确定的拉娜DNA结合结构域的X射线晶体结构的基础上。本项目的风险通过我们开发靶向EB病毒蛋白EBNA 1的小分子抑制剂（与拉娜的结构和功能相似）的经验进一步降低。我们使用高通量筛选、晶体学和基于结构的药物设计方法来优化对EBNA 1具有中低纳摩尔活性的先导化合物的有效命中。在R 01提案中，我们计划采用类似的策略来鉴定和优化用于治疗KSHV相关疾病的拉娜抑制剂。

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.