Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA.
Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, Oregon, USA
J Virol. 2018 Sep 26;92(20). doi: 10.1128/JVI.01269-18. Print 2018 Oct 15.
Herpes simplex virus (HSV) and other alphaherpesviruses must spread from sites of viral latency in sensory ganglia to peripheral tissues, where the viruses can replicate to higher titers before spreading to other hosts. These viruses move in neuronal axons from ganglia to the periphery propelled by kinesin motors moving along microtubules. Two forms of HSV particles undergo this anterograde transport in axons: (i) unenveloped capsids that become enveloped after reaching axon tips and (ii) enveloped virions that are transported within membrane vesicles in axons. Fundamental to understanding this axonal transport is the question of which of many different axonal kinesins convey HSV particles. Knowing which kinesins promote axonal transport would provide clues to the identity of HSV proteins that tether onto kinesins. Prominent among axonal kinesins are the kinesin-1 (KIF5A, -5B, and -5C) and kinesin-3 (e.g., KIF1A and -1B) families. We characterized fluorescent forms of cellular cargo molecules to determine if enveloped HSV particles were present in the vesicles containing these cargos. Kinesin-1 cargo proteins were present in vesicles containing HSV particles, but not kinesin-3 cargos. Fluorescent kinesin-1 protein KIF5C extensively colocalized with HSV particles, while fluorescent kinesin-1 KIF1A did not. Silencing of kinesin-1 proteins KIF5A, -5B, and -5C or light chains KLC1 and KLC2 inhibited the majority of HSV anterograde transport, while silencing of KIF1A had little effect on HSV transport in axons. We concluded that kinesin-1 proteins are important in the anterograde transport of the majority of HSV enveloped virions in neuronal axons and kinesin-3 proteins are less important. Herpes simplex virus (HSV) and other alphaherpesviruses, such as varicella-zoster virus, depend upon the capacity to navigate in neuronal axons. To do this, virus particles tether onto dyneins and kinesins that motor along microtubules from axon tips to neuronal cell bodies (retrograde) or from cell bodies to axon tips (anterograde). Following reactivation from latency, alphaherpesviruses absolutely depend upon anterograde transport of virus particles in axons in order to reinfect peripheral tissues and spread to other hosts. Which of the many axonal kinesins transport HSV in axons is not clear. We characterized fluorescent cellular cargo molecules and kinesins to provide evidence that HSV enveloped particles are ferried by kinesin-1 proteins KIF5A, -5B, and -5C and their light chains, KLC1 and KLC2, in axons. Moreover, we obtained evidence that kinesin-1 proteins are functionally important in anterograde transport of HSV virions by silencing these proteins.
单纯疱疹病毒 (HSV) 和其他α疱疹病毒必须从感觉神经节中的潜伏部位传播到周围组织，在这些部位，病毒可以复制到更高的滴度，然后再传播到其他宿主。这些病毒通过沿着微管移动的驱动蛋白马达在神经元轴突中从神经节移动到外周。两种形式的 HSV 颗粒在轴突中经历这种顺行转运：(i) 未包膜的衣壳，在到达轴突末端后包膜；(ii) 包膜病毒，在轴突内的膜小泡中运输。理解这种轴突运输的基础是一个问题，即许多不同的轴突驱动蛋白中，哪一种携带 HSV 颗粒。了解哪些驱动蛋白促进轴突运输将为确定与驱动蛋白结合的 HSV 蛋白的身份提供线索。在轴突驱动蛋白中，突出的是驱动蛋白-1（KIF5A、-5B 和 -5C）和驱动蛋白-3（例如 KIF1A 和 -1B）家族。我们对细胞货物分子的荧光形式进行了表征，以确定包膜 HSV 颗粒是否存在于含有这些货物的小泡中。驱动蛋白-1 货物蛋白存在于含有 HSV 颗粒的小泡中，但不存在驱动蛋白-3 货物蛋白。荧光驱动蛋白-1 蛋白 KIF5C 与 HSV 颗粒广泛共定位，而荧光驱动蛋白-1 蛋白 KIF1A 则没有。驱动蛋白-1 蛋白 KIF5A、-5B 和 -5C 或轻链 KLC1 和 KLC2 的沉默抑制了大多数 HSV 的顺行运输，而 KIF1A 的沉默对 HSV 在轴突中的运输几乎没有影响。我们得出结论，驱动蛋白-1 蛋白在神经元轴突中大多数 HSV 包膜病毒颗粒的顺行运输中很重要，而驱动蛋白-3 蛋白的作用则不那么重要。单纯疱疹病毒 (HSV) 和其他α疱疹病毒，如水痘带状疱疹病毒，依赖于在神经元轴突中导航的能力。为此，病毒颗粒与动力蛋白和驱动蛋白结合，沿着微管从轴突末端向神经元细胞体（逆行）或从细胞体向轴突末端（顺行）移动。从潜伏状态重新激活后，α疱疹病毒绝对依赖于病毒颗粒在轴突中的顺行运输，以便重新感染周围组织并传播到其他宿主。哪些是携带 HSV 的众多轴突驱动蛋白尚不清楚。我们对荧光细胞货物分子和驱动蛋白进行了表征，提供了证据表明，HSV 包膜颗粒由驱动蛋白-1 蛋白 KIF5A、-5B 和 -5C 及其轻链 KLC1 和 KLC2 在轴突中运输。此外，我们通过沉默这些蛋白获得了证据，证明驱动蛋白-1 蛋白在 HSV 病毒颗粒的顺行运输中具有功能重要性。
