Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America.
PLoS Pathog. 2020 Dec 28;16(12):e1008861. doi: 10.1371/journal.ppat.1008861. eCollection 2020 Dec.
Alpha-herpesviruses establish a life-long infection in the nervous system of the affected host; while this infection is restricted to peripheral neurons in a healthy host, the reactivated virus can spread within the neuronal circuitry, such as to the brain, in compromised individuals and lead to adverse health outcomes. Pseudorabies virus (PRV), an alpha-herpesvirus, requires the viral protein Us9 to sort virus particles into axons and facilitate neuronal spread. Us9 sorts virus particles by mediating the interaction of virus particles with neuronal transport machinery. Here, we report that Us9-mediated regulation of axonal sorting also depends on the state of neuronal maturation. Specifically, the development of dendrites and axons is accompanied with proteomic changes that influence neuronal processes. Immature superior cervical ganglionic neurons (SCGs) have rudimentary neurites that lack markers of mature axons. Immature SCGs can be infected by PRV, but they show markedly reduced Us9-dependent regulation of sorting, and increased Us9-independent transport of particles into neurites. Mature SCGs have relatively higher abundances of proteins characteristic of vesicle-transport machinery. We also identify Us9-associated neuronal proteins that can contribute to axonal sorting and subsequent anterograde spread of virus particles in axons. We show that SMPD4/nsMase3, a sphingomyelinase abundant in lipid-rafts, associates with Us9 and is a negative regulator of PRV sorting into axons and neuronal spread, a potential antiviral function.
α疱疹病毒在受感染宿主的神经系统中建立终身感染；虽然这种感染局限于健康宿主的周围神经元，但在免疫功能低下的个体中，再激活的病毒可以在神经元回路中扩散，例如传播到大脑，并导致不良的健康后果。伪狂犬病病毒 (PRV) 是一种α疱疹病毒，需要病毒蛋白 Us9 将病毒颗粒分拣到轴突中，并促进神经元传播。Us9 通过介导病毒颗粒与神经元运输机制的相互作用来分拣病毒颗粒。在这里，我们报告说，Us9 介导的轴突分拣调节还取决于神经元成熟的状态。具体来说，树突和轴突的发育伴随着影响神经元过程的蛋白质组变化。未成熟的颈上交感神经节 (SCG) 神经元具有原始的神经突，缺乏成熟轴突的标志物。未成熟的 SCG 可以被 PRV 感染，但它们显示出明显减少的 Us9 依赖性分拣调节，以及增加的 Us9 非依赖性颗粒向神经突的运输。成熟的 SCG 具有相对较高丰度的特征性囊泡运输机制的蛋白质。我们还鉴定了与 Us9 相关的神经元蛋白，这些蛋白可以促进轴突分拣，并随后促进病毒颗粒在轴突中的顺行传播。我们表明，富含脂筏的鞘磷脂酶 SMPD4/nsMase3 与 Us9 相关，是 PRV 分拣到轴突和神经元传播的负调节剂，这是一种潜在的抗病毒功能。
