Viral lncRNA: A regulatory molecule for controlling virus life cycle

Wang, Ziqiang; Zhao, Yiwan; Zhang, Yaou

Some viruses undergo a lysogenic cycle where the viral genome is incorporated into a specific location in the host's chromosome by genetic recombination. Thus, the viral genome is replicated whenever the host divides. In most situations, the concerted effort of the innate and adaptive responses is effective in eliminating the pathogen. However, in some cases, the acute resolution of infection is incomplete and viral persistence results. Herpes simplex virus, Heliothis zea nudivirus 1 (HzNV-1), adenovirus virus and Theiler's virus are hallmark examples of infections that develop lifelong viral persistence by "hiding" from the immune response. In contrast to the many viral translated and induced proteins involved in maintaining persistent infections by direct inhibition of T cell responses and/or by down-regulating antigen recognition molecules [24, 25] , some lncRNAs have been shown to be responsible for derailing the immune response to permit viral persistence. Tmevpg1, which is a long intergenic non-coding RNA, controls persistent infection with Theiler's virus by positively regulating IFN-gamma expression; this process is dependent on Stat4 and T-bet, which are the two transcription factors that drive the Th1 differentiation program [26e28].