Department of Microbiology and Immunology, Uniformed Services University, Bethesda, MD, 20814, USA.
Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA.
Virol J. 2018 Mar 27;15(1):56. doi: 10.1186/s12985-018-0964-0.
Hendra virus and Nipah virus are zoonotic viruses that have caused severe to fatal disease in livestock and human populations. The isolation of Cedar virus, a non-pathogenic virus species in the genus Henipavirus, closely-related to the highly pathogenic Hendra virus and Nipah virus offers an opportunity to investigate differences in pathogenesis and receptor tropism among these viruses.
We constructed full-length cDNA clones of Cedar virus from synthetic oligonucleotides and rescued two replication-competent, recombinant Cedar virus variants: a recombinant wild-type Cedar virus and a recombinant Cedar virus that expresses a green fluorescent protein from an open reading frame inserted between the phosphoprotein and matrix genes. Replication kinetics of both viruses and stimulation of the interferon pathway were characterized in vitro. Cellular tropism for ephrin-B type ligands was qualitatively investigated by microscopy and quantitatively by a split-luciferase fusion assay.
Successful rescue of recombinant Cedar virus expressing a green fluorescent protein did not significantly affect virus replication compared to the recombinant wild-type Cedar virus. We demonstrated that recombinant Cedar virus stimulated the interferon pathway and utilized the established Hendra virus and Nipah virus receptor, ephrin-B2, but not ephrin-B3 to mediate virus entry. We further characterized virus-mediated membrane fusion kinetics of Cedar virus with the known henipavirus receptors ephrin-B2 and ephrin-B3.
The recombinant Cedar virus platform may be utilized to characterize the determinants of pathogenesis across the henipaviruses, investigate their receptor tropisms, and identify novel pan-henipavirus antivirals. Moreover, these experiments can be conducted safely under BSL-2 conditions.
亨德拉病毒和尼帕病毒是两种人畜共患病病毒，已导致家畜和人群发生严重至致命疾病。雪松病毒是亨尼帕病毒属中的一种非致病性病毒，与高致病性亨德拉病毒和尼帕病毒密切相关，它的分离为研究这些病毒在发病机制和受体嗜性方面的差异提供了机会。
我们从合成寡核苷酸构建了雪松病毒全长 cDNA 克隆，并拯救了两种具有复制能力的重组雪松病毒变体：重组野生型雪松病毒和一种在磷蛋白和基质基因之间插入开放阅读框表达绿色荧光蛋白的重组雪松病毒。在体外研究了这两种病毒的复制动力学和干扰素途径的刺激作用。通过显微镜和荧光素酶融合分析对细胞对 Ephrin-B 型配体的嗜性进行了定性和定量研究。
与重组野生型雪松病毒相比，成功拯救表达绿色荧光蛋白的重组雪松病毒对病毒复制的影响并不显著。我们证明重组雪松病毒可刺激干扰素途径，并利用已建立的亨德拉病毒和尼帕病毒受体 Ephrin-B2，但不利用 Ephrin-B3 来介导病毒进入。我们进一步研究了雪松病毒与已知亨尼帕病毒受体 Ephrin-B2 和 Ephrin-B3 之间的病毒介导的膜融合动力学。
重组雪松病毒平台可用于研究亨尼帕病毒之间发病机制的决定因素、研究它们的受体嗜性，并鉴定新型泛亨尼帕病毒抗病毒药物。此外，这些实验可以在 BSL-2 条件下安全进行。
