Neuron-virus interactions that occur during herpes simplex virus (HSV) infection are not fully understood. Neurons are the site of lifelong latency and are a crucial target for long-term suppressive therapy or viral clearance. A reproducible neuronal model of human origin would facilitate studies of HSV and other neurotropic viruses. Current neuronal models in the herpesvirus field vary widely and have caveats, including incomplete differentiation, nonhuman origins, or the use of dividing cells that have neuropotential but lack neuronal morphology. In this study, we used a robust approach to differentiate human SH-SY5Y neuroblastoma cells over 2.5 weeks, producing a uniform population of mature human neuronal cells. We demonstrate that terminally differentiated SH-SY5Y cells have neuronal morphology and express proteins with subcellular localization indicative of mature neurons. These neuronal cells are able to support a productive HSV-1 infection, with kinetics and overall titers similar to those seen in undifferentiated SH-SY5Y cells and the related SK-N-SH cell line. However, terminally differentiated, neuronal SH-SY5Y cells release significantly less extracellular HSV-1 by 24 h postinfection (hpi), suggesting a unique neuronal response to viral infection. With this model, we are able to distinguish differences in neuronal spread between two strains of HSV-1. We also show expression of the antiviral protein cyclic GMP-AMP synthase (cGAS) in neuronal SH-SY5Y cells, which is the first demonstration of the presence of this protein in nonepithelial cells. These data provide a model for studying neuron-virus interactions at the single-cell level as well as via bulk biochemistry and will be advantageous for the study of neurotropic viruses in vitro.

IMPORTANCE Herpes simplex virus (HSV) affects millions of people worldwide, causing painful oral and genital lesions, in addition to a multitude of more severe symptoms such as eye disease, neonatal infection, and, in rare cases, encephalitis. Presently, there is no cure available to treat those infected or prevent future transmission. Due to the ability of HSV to cause a persistent, lifelong infection in the peripheral nervous system, the virus remains within the host for life. To better understand the basis of virus-neuron interactions that allow HSV to persist within the host peripheral nervous system, improved neuronal models are required. Here we describe a cost-effective and scalable human neuronal model system that can be used to study many neurotropic viruses, such as HSV, Zika virus, dengue virus, and rabies virus.

单纯疱疹病毒 (HSV) 感染期间发生的神经元病毒相互作用尚不完全清楚。神经元是终生潜伏的部位，是长期抑制治疗或病毒清除的关键目标。人类起源的可重复神经元模型将有助于 HSV 和其他嗜神经病毒的研究。目前疱疹病毒领域的神经元模型差异很大，并且有一些警告，包括不完全分化、非人类起源或使用具有神经潜能但缺乏神经元形态的分裂细胞。在这项研究中，我们使用一种稳健的方法在 2.5 周内分化人类 SH-SY5Y 神经母细胞瘤细胞，从而产生均匀的成熟人类神经元细胞群。我们证明终末分化的 SH-SY5Y 细胞具有神经元形态并表达具有指示成熟神经元的亚细胞定位的蛋白质。这些神经元细胞能够支持生产性 HSV-1 感染，其动力学和总体滴度与未分化的 SH-SY5Y 细胞和相关的 SK-N-SH 细胞系中所见的相似。然而，终末分化的神经元 SH-SY5Y 细胞在感染后 24 小时 (hpi) 释放的细胞外 HSV-1 显着减少，表明对病毒感染的独特神经元反应。使用这个模型，我们能够区分两种 HSV-1 菌株之间神经元分布的差异。我们还展示了抗病毒蛋白环状 GMP-AMP 合酶 (cGAS) 在神经元 SH-SY5Y 细胞中的表达，这是首次证明该蛋白在非上皮细胞中的存在。体外。

重要性单纯疱疹病毒 (HSV) 影响着全世界数百万人，除了引起眼部疾病、新生儿感染等许多更严重的症状外，还导致疼痛的口腔和生殖器损伤，在极少数情况下还会出现脑炎。目前，没有可用的治疗方法来治疗感染者或预防未来的传播。由于 HSV 能够在周围神经系统中引起持续的、终生的感染，病毒会终生留在宿主体内。为了更好地理解允许 HSV 在宿主周围神经系统内持续存在的病毒-神经元相互作用的基础，需要改进的神经元模型。在这里，我们描述了一种具有成本效益且可扩展的人类神经元模型系统，可用于研究许多嗜神经病毒，例如 HSV、寨卡病毒、登革热病毒和狂犬病病毒。