Sadaoka Tomohiko, Depledge Daniel P, Rajbhandari Labchan, Venkatesan Arun, Breuer Judith, Cohen Jeffrey I
Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892;
Division of Infection and Immunity, MRC Centre for Medical Molecular Virology, University College London, London WC1E 6BT, United Kingdom;
Proc Natl Acad Sci U S A. 2016 Apr 26;113(17):E2403-12. doi: 10.1073/pnas.1522575113. Epub 2016 Apr 12.
Varicella-zoster virus (VZV) establishes latency in human sensory and cranial nerve ganglia during primary infection (varicella), and the virus can reactivate and cause zoster after primary infection. The mechanism of how the virus establishes and maintains latency and how it reactivates is poorly understood, largely due to the lack of robust models. We found that axonal infection of neurons derived from hESCs in a microfluidic device with cell-free parental Oka (POka) VZV resulted in latent infection with inability to detect several viral mRNAs by reverse transcriptase-quantitative PCR, no production of infectious virus, and maintenance of the viral DNA genome in endless configuration, consistent with an episome configuration. With deep sequencing, however, multiple viral mRNAs were detected. Treatment of the latently infected neurons with Ab to NGF resulted in production of infectious virus in about 25% of the latently infected cultures. Axonal infection of neurons with vaccine Oka (VOka) VZV resulted in a latent infection similar to infection with POka; however, in contrast to POka, VOka-infected neurons were markedly impaired for reactivation after treatment with Ab to NGF. In addition, viral transcription was markedly reduced in neurons latently infected with VOka compared with POka. Our in vitro system recapitulates both VZV latency and reactivation in vivo and may be used to study viral vaccines for their ability to establish latency and reactivate.
水痘带状疱疹病毒（VZV）在初次感染（水痘）期间在人类感觉神经节和颅神经节中建立潜伏感染，并且该病毒在初次感染后可重新激活并引起带状疱疹。病毒如何建立和维持潜伏感染以及如何重新激活的机制目前尚不清楚，这主要是由于缺乏可靠的模型。我们发现，在微流控装置中，无细胞的亲本Oka（POka）VZV对源自人胚胎干细胞的神经元进行轴突感染会导致潜伏感染，通过逆转录定量PCR无法检测到几种病毒mRNA，不产生感染性病毒，并且病毒DNA基因组以环状构型维持，这与附加体构型一致。然而，通过深度测序检测到了多种病毒mRNA。用抗NGF抗体处理潜伏感染的神经元会导致约25%的潜伏感染培养物产生感染性病毒。用疫苗Oka（VOka）VZV对神经元进行轴突感染会导致与POka感染相似的潜伏感染；然而，与POka不同的是，用抗NGF抗体处理后，VOka感染的神经元重新激活明显受损。此外，与POka相比，VOka潜伏感染的神经元中病毒转录明显减少。我们的体外系统概括了VZV在体内的潜伏和重新激活过程，可用于研究病毒疫苗建立潜伏感染和重新激活的能力。
