Mechanisms of varicella virus dissemination

摘要 水痘带状疱疹病毒(VZV)是一种高度传染性、嗜神经的阿尔法疱疹病毒，可引起 水痘(水痘)。VZV在感觉神经节中建立潜伏期，从中可以重新激活 引起带状疱疹(带状疱疹)，这是一种令人痛苦的疾病，影响着世界上近100万人 美国每年都有。在初次感染期间，VZV通过吸入病毒传播 颗粒，但VZV从最初的感染部位传播到神经节的机制 皮肤情况仍不明朗。来自体外测试和体内研究的数据使用了严重的- 植入人胎儿组织的联合免疫缺陷小鼠(SCID-HU)强烈建议 T细胞对VZV感染高度易感，可能在VZV发病中起关键作用 扩散到皮肤和神经节。然而，SCID-HU小鼠模型有两个主要的 局限性：1)缺乏适应性免疫系统，2)严格的人类 在这个小鼠模型中，VZV的宿主特异性可能改变了病毒的行为。此外，在体外 用减毒OKA疫苗株对人扁桃体T细胞进行了研究，该疫苗株 可能不能充分模拟感染野生型病毒株的结果。在此应用程序中， 我们建议定义VZV篡夺T细胞通过使用恒河猴传播的机制 再现VZV感染特征的猕猴模型。在这个模型中，恒河猴 被呼吸道感染的是猴水痘病毒(SVV)，它是VZV的同源物。我们有 证明了常驻肺的T细胞对SVV感染是敏感和允许的。 此外，早在感染后3天，在神经节中就检测到记忆T细胞 与病毒DNA同时，在检测到病毒特异性T细胞反应之前。虽然 这些观察证实了SVV中T细胞在传播到神经节中的重要作用，因为 已经被建议用于VZV，水痘病毒劫持宿主的机制 T细胞扩散到潜伏部位的定义仍然很模糊。在此应用程序中，我们将 通过首先确定SVV引起的转录变化来解决这一关键的知识鸿沟 利用高通量单细胞在急性感染期间从肺中分离的T细胞的感染 RNA测序。然后，我们将评估SVV-代谢和迁移功能的变化- 在体外感染T细胞。完成这项申请中提出的研究将产生新的 在单细胞水平上洞察病毒与宿主的相互作用，并将作为研究的模型 其他嗜T细胞病毒的致病机制。

SUMMARY Varicella zoster virus (VZV) is a highly contagious, neurotropic alpha herpes virus that causes varicella (chickenpox). VZV establishes latency in the sensory ganglia from which it can reactivate to cause herpes zoster (shingles), a painful disease that affects almost 1 million individuals in the United States annually. During primary infection VZV is transmitted through the inhalation of viral particles, but the mechanisms by which VZV traffics from the initial site of infection to the ganglia and skin remain unclear. Data from in vitro assays as well as in vivo studies using severe- combined immunodeficient mice implanted with human fetal tissues (SCID-hu) strongly suggest that T cells are highly susceptible to VZV infection and may play a critical role in VZV dissemination to the skin and ganglia. However, the SCID-hu mouse model has two major limitations: 1) the lack of an adaptive immune system and 2) the possibility that the strict human host specificity of VZV could have altered viral behavior in this murine model. Additionally, in vitro studies of human tonsillar T cells were carried out using the attenuated Oka vaccine strain, which may not adequately model the outcome of infection with wild type viral strains. In this application, we propose to define the mechanisms by which VZV usurps T cells to spread by using a rhesus macaque model that recapitulates the hallmarks of VZV infection. In this model, rhesus macaques are intra-bronchially infected with Simian varicella virus (SVV), a homolog of VZV. We have demonstrated that lung-resident T cells are susceptible and permissive to SVV infection. Additionally, memory T cells are detected in the ganglia as early as 3 days post-infection, at the same time as viral DNA and before the detection of a viral-specific T cell response. Although these observations establish a significant role for T cells in SVV spread to the ganglia, as has been suggested for VZV, the mechanism by which varicella viruses hijack the host’s T cells to disseminate to latency sites remain poorly defined. In this application, we will address this critical knowledge gap by first identifying transcriptional changes induced by SVV infection in T cells isolated from the lung during acute infection using high throughput single cell RNA sequencing. Then, we will assess alterations in metabolic and migratory function of SVV- infected T cells in vitro. Completion of the studies proposed in this application will yield novel insight into viral-host interactions at the single cell level and will serve as a model to investigate the pathogenesis of other T cell tropic viruses.