Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
Viruses. 2019 Mar 1;11(3):206. doi: 10.3390/v11030206.
Filoviruses, such as Ebola virus (EBOV) and Marburg virus, are causative agents of unpredictable outbreaks of severe hemorrhagic fevers in humans and non-human primates. For infection, filoviral particles need to be internalized and delivered to intracellular vesicles containing cathepsin proteases and the viral receptor Niemann-Pick C1. Previous studies have shown that EBOV triggers macropinocytosis of the viral particles in a glycoprotein (GP)-dependent manner, but the molecular events required for filovirus internalization remain mostly unknown. Here we report that the diacylglycerol kinase inhibitor, R-59-022, blocks EBOV GP-mediated entry into Vero cells and bone marrow-derived macrophages. Investigation of the mode of action of the inhibitor revealed that it blocked an early step in entry, more specifically, the internalization of the viral particles via macropinocytosis. Finally, R-59-022 blocked viral entry mediated by a panel of pathogenic filovirus GPs and inhibited growth of replicative Ebola virus. Taken together, our studies suggest that R-59-022 could be used as a tool to investigate macropinocytic uptake of filoviruses and could be a starting point for the development of pan-filoviral therapeutics.
丝状病毒，如埃博拉病毒（EBOV）和马尔堡病毒，是导致人类和非人灵长类动物严重出血性发热不可预测爆发的病原体。对于感染，丝状病毒颗粒需要被内化并递送至含有组织蛋白酶蛋白酶和病毒受体尼曼-匹克 C1 的细胞内小泡中。先前的研究表明，EBOV 以糖蛋白（GP）依赖性方式触发病毒颗粒的巨胞饮作用，但丝状病毒内化所需的分子事件在很大程度上仍不清楚。在这里，我们报告说二酰基甘油激酶抑制剂 R-59-022 阻断了 EBOV GP 介导的进入 Vero 细胞和骨髓来源的巨噬细胞。对抑制剂作用模式的研究表明，它阻断了进入的早期步骤，更具体地说，通过巨胞饮作用内化了病毒颗粒。最后，R-59-022 阻断了一组致病性丝状病毒 GPs 介导的病毒进入，并抑制了复制性埃博拉病毒的生长。总之，我们的研究表明，R-59-022 可用于研究丝状病毒的巨胞饮摄取，并可能成为开发泛丝状病毒治疗药物的起点。
