Targeting the host NDP kinase to abrogate viral dissemination

项目摘要 迫切需要开发针对严重肿瘤的安全有效的治疗方法， 人类病原体，如卡波西肉瘤疱疹病毒（KSHV），其导致显著的发病率， 免疫受损个体的死亡率，并且仍然是临床挑战。目前，没有FDA批准 治疗剂或疫苗可用于KSHV感染。鉴于KSHV和其他人类疱疹病毒 劫持宿主蛋白质和途径以完成其复制周期并在细胞间传播， 针对这些途径和机制将提供广谱基因型覆盖和高屏障， to drug药物resistance抗性.长期以来，已知包括KSHV在内的疱疹病毒利用COPII介导的免疫抑制作用。 成熟的分泌途径。然而，管理这一过程的机制仍然较少， 明白这个项目将填补这一空白，利用我们最近的发现， 二磷酸激酶NM 23-H2是COPII囊泡转运的重要调节剂，被KSHV利用， 它们的病毒体形态发生和扩散我们发现KSHV的病毒Bcl-2（ks-Bcl-2）直接与， 在KSHV的裂解期稳定并活化NM 23-H2。NM 23-H2缺失或ks-Bcl-2突变， NM 23-H2相互作用的消失严重损害了病毒体的产生。因此，我们假设KSHV激活 宿主蛋白NM 23-H2利用COPII途径进行有效的病毒体组装和释放，解开 病毒生命周期中的一个关键检查点，可用于新的抗病毒治疗。我们现在带来 在该提案中，KSHV生物学和小分子抑制剂设计方面的专家合作， 确定负责KSHV病毒体产生细胞途径并开发抑制病毒的新策略 传输为了实现这一目标，我们提出了两个具体目标，包括（1）定义分子 KSHV ks-Bcl-2靶向NM 23-H2激活Sar 1介导的COPII转运的机制， （2）靶向ks-Bcl-2-NM 23-H2介导的COPII机制以阻断KSHV增殖。 这些目标将使用多学科方法来解决，这些方法将最先进的遗传学， 生物化学、活细胞成像和生理学测定。总之，我们预计我们的研究将确定 宿主基因/途径在病毒装配和外出中发挥作用，并提供令人信服的体内验证， 靶向NM 23-H2依赖性宿主机制可以消除病毒在宿主内和宿主间的传播 个体

Project Summary There is an urgent and unmet need for the development of safe and effective therapeutics against serious human pathogens such as Kaposi's sarcoma herpesvirus (KSHV), which causes significant morbidity and mortality in immune-compromised individuals and remains a clinical challenge. Currently, no FDA approved therapeutics or vaccines are available for KSHV infection. Given that KSHV and other human herpesviruses hijack host proteins and pathways to complete their replication cycles and spread from cell to cell, strategies targeting these pathways and mechanisms will provide broad-spectrum genotype coverage and a high barrier to drug resistance. Herpesviruses including KSHV have long been known to exploit the COPII-mediated secretory pathway for their maturation. However, the mechanisms governing this process remain less understood. This project will fill this gap, capitalizing on our recent discovery that the host nucleoside diphosphates kinase NM23-H2, an important regulator of COPII vesicle transport, is exploited by KSHV for their virion morphogenesis and egress. We found that viral Bcl-2 of KSHV (ks-Bcl-2) directly interacted with, stabilized, and activated NM23-H2 during lytic phase of KSHV. Loss of NM23-H2 or mutations in ks-Bcl-2 that abolished NM23-H2 interaction severely impaired virion production. We thus hypothesize that KSHV activates host protein NM23-H2 to exploit the COPII pathway for efficient virion assembly and release, unraveling a key checkpoint in virus lifecycle that can be targeted for new antiviral therapeutics. We now bring within this proposal a collaboration of experts in KSHV biology and in design of small-molecule inhibitors to identify cellular pathway responsible for virion production of KSHV and develop a new strategy to dampen virus transmission. To achieve this goal, we propose two specific aims, including (1) defining the molecular mechanism by which KSHV ks-Bcl-2 targets NM23-H2 to activate Sar1-mediated COPII transport for efficient virion assembly; and (2) targeting ks-Bcl-2-NM23-H2-mediated COPII mechanism to block KSHV propagation. These aims will be addressed using multidisciplinary approaches that integrate state-of-the-art genetic, biochemistry, live-cell imaging, and physiological assays. Together, we anticipate that our studies will identify host genes/pathways that function in virus assembly and egress, and provide compelling in vivo validation that targeting NM23-H2-dependent host mechanism can abrogate virus transmission within and between individuals.