Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS, USA.
Lawrence Livermore National Laboratory, Livermore, CA, USA.
Virology. 2018 Nov;524:78-89. doi: 10.1016/j.virol.2018.08.006. Epub 2018 Aug 27.
In order to study the mechanism of PRRSV persistence, an in vitro model of persistence was developed by serially passaging PRRSV-infected MARC-145 cells 109 times. Viral persistence was detected to be associated with increased double-stranded (dsRNA) in the infected cells. In PRRSV infected pigs, reduced ratio of plus to minus strands of viral RNA was observed in lymphoid tissues from PRRSV persistent pigs at 52 days post infection. Viral dsRNA was mostly detected in the germinal center during persistent infection compared to the localization of dsRNA in the inter-follicular zones during acute infection. RNA array analysis of antiviral cytokines in persistently infected lymph nodes showed that the presence of dsRNA did not stimulate antiviral immunity. These results suggest that PRRSV dsRNA functions as a mediator for viral persistence. The localization of PRRSV dsRNA in the germinal center of lymphoid tissues reveals a novel mechanism for PRRSV persistence.
为了研究 PRRSV 持续感染的机制，通过连续传代感染 MARC-145 细胞 109 次，建立了 PRRSV 持续感染的体外模型。研究发现病毒持续感染与感染细胞中双链 RNA（dsRNA）的增加有关。在 PRRSV 感染的猪中，在感染后 52 天，持续性 PRRSV 感染猪的淋巴组织中病毒 RNA 的正链与负链的比例降低。与急性感染时 dsRNA 在滤泡间区的定位相比，持续性感染时 dsRNA 主要在生发中心检测到。对持续性感染淋巴结中抗病毒细胞因子的 RNA 阵列分析表明，dsRNA 的存在并没有刺激抗病毒免疫。这些结果表明，PRRSV dsRNA 作为病毒持续感染的介质发挥作用。PRRSV dsRNA 在淋巴组织生发中心的定位揭示了 PRRSV 持续感染的一种新机制。
