The number of alphaherpesvirus particles infecting axons and the axonal protein repertoire determines the outcome of neuronal infection.
The number of alphaherpesvirus particles infecting axons and the axonal protein repertoire determines the outcome of neuronal infection.
复制标题
DOI：
10.1128/mbio.00276-15
复制
发表时间：
2015-03-24
期刊：
影响因子：
6.4
通讯作者：
Enquist LW
中科院分区：
文献类型：
--
作者：
Koyuncu OO;Song R;Greco TM;Cristea IM;Enquist LW
甲疱疹病毒感染总是导致周围神经系统（PNS）的侵袭和潜伏性或生产性感染的建立。感染开始于轴突中的病毒衣壳和被膜蛋白向神经元核的长距离逆行运输。轴突进入、逆行运输和在神经元核中复制的初始步骤知之甚少。为了更好地理解PNS中的感染模式是如何确定的，我们利用了隔室神经元培养系统，其中PNS神经元的远端轴突与细胞体物理分离。我们用荧光蛋白标记的伪狂犬病病毒（PRV）颗粒感染分离的轴突，并在低和高感染复数（MOI为0.01至100）期间监测病毒进入轴突和运输以及在细胞体中的复制。我们发现了一个阈值，有效的逆行运输在轴突之间的MOIs 1和10和阈值之间的MOIs 1和0.1的神经元细胞体的生产性感染。MOI低于0.1时，转移到神经元细胞核的病毒基因组会被沉默。这些基因组在被非复制型病毒重复感染后可以被重新激活，但不能被复制型病毒激活。我们进一步表明，在高MOI感染的病毒颗粒竞争轴突蛋白，这种竞争决定了到达细胞核的病毒颗粒的数量。使用质谱，我们确定了差异调节PRV感染的轴突蛋白。我们的研究结果表明，感染的多重性和轴突环境的影响，建立神经元感染发起的轴突。α疱疹病毒基因组可能在宿主的生命中在外周神经系统（PNS）神经元中保持沉默。这些基因组偶尔会重新激活，产生感染性病毒，这些病毒可以再次感染外周组织并传播到其他宿主。在这里，我们使用一个神经元培养系统来研究轴突感染的结果，使用不同数量的病毒颗粒和共感染试验。我们发现病毒进入、运输和复制的动态变化取决于感染轴突的病毒颗粒的数量。我们证明，病毒基因组沉默时，感染的颗粒数是低的，这些基因组可以重新激活与紫外线灭活病毒的超感染，但不是复制病毒。我们进一步表明，病毒的入侵迅速改变了轴突蛋白的配置文件，这些轴突蛋白中的一些是有效感染的速率限制。我们的研究提供了新的见解建立沉默与生产性α疱疹病毒感染的PNS。
Infection by alphaherpesviruses invariably results in invasion of the peripheral nervous system (PNS) and establishment of either a latent or productive infection. Infection begins with long-distance retrograde transport of viral capsids and tegument proteins in axons toward the neuronal nuclei. Initial steps of axonal entry, retrograde transport, and replication in neuronal nuclei are poorly understood. To better understand how the mode of infection in the PNS is determined, we utilized a compartmented neuron culturing system where distal axons of PNS neurons are physically separated from cell bodies. We infected isolated axons with fluorescent-protein-tagged pseudorabies virus (PRV) particles and monitored viral entry and transport in axons and replication in cell bodies during low and high multiplicities of infection (MOIs of 0.01 to 100). We found a threshold for efficient retrograde transport in axons between MOIs of 1 and 10 and a threshold for productive infection in the neuronal cell bodies between MOIs of 1 and 0.1. Below an MOI of 0.1, the viral genomes that moved to neuronal nuclei were silenced. These genomes can be reactivated after superinfection by a nonreplicating virus, but not by a replicating virus. We further showed that viral particles at high-MOI infections compete for axonal proteins and that this competition determines the number of viral particles reaching the nuclei. Using mass spectrometry, we identified axonal proteins that are differentially regulated by PRV infection. Our results demonstrate the impact of the multiplicity of infection and the axonal milieu on the establishment of neuronal infection initiated from axons. Alphaherpesvirus genomes may remain silent in peripheral nervous system (PNS) neurons for the lives of their hosts. These genomes occasionally reactivate to produce infectious virus that can reinfect peripheral tissues and spread to other hosts. Here, we use a neuronal culture system to investigate the outcome of axonal infection using different numbers of viral particles and coinfection assays. We found that the dynamics of viral entry, transport, and replication change dramatically depending on the number of virus particles that infect axons. We demonstrate that viral genomes are silenced when the infecting particle number is low and that these genomes can be reactivated by superinfection with UV-inactivated virus, but not with replicating virus. We further show that viral invasion rapidly changes the profiles of axonal proteins and that some of these axonal proteins are rate limiting for efficient infection. Our study provides new insights into the establishment of silent versus productive alphaherpesvirus infections in the PNS.