ROLE OF THE LAT-ICP0 LOCUS IN REGULATING HSV LATENCY

描述（由申请人提供）：单纯疱疹病毒（HSV）的复发性感染是一个重要的临床问题。理解复发性疱疹性疾病的本质的基础是精确地确定HSV如何在其双重生命周期的两个阶段之间交替，潜伏期和生产性感染的重新激活。LAT-ICP 0基因座在HSV-1潜伏期和再激活的调节中起核心作用。编码潜伏相关转录物（LAT）和感染细胞多肽0（ICP 0）的基因在HSV基因组的重复区域中形成连续的基因座。具体而言，LAT和ICP 0基因位于HSV-1双链DNA基因组的相对链上，并且有显著的重叠。因此，丰富的LAT可以与ICP 0 mRNA中0.75个碱基的互补序列杂交。虽然LAT-ICP 0基因座的反义排列早已被认识到，但LAT RNA作为ICP 0基因表达的“反义阻遏物”的假设尚未得到严格分析。LAT和ICP 0基因的并列反映了它们在潜伏期中的相反作用。虽然LAT RNA促进HSV潜伏期的维持，但ICP 0的表达是诱导HSV-1再活化所必需且足够的。相反，ICP 0表达失败高度有利于HSV基因组进入转录抑制状态。因此，ICP 0 mRNA翻译的反义抑制是LATs可能有助于维持潜伏期的一种机制。这项研究计划的目的是评估LAT RNA和ICP 0形成一对相互依赖、相反的调节因子的概念，这对调节因子是HSV潜伏期的阴阳。具体而言，将获得遗传学证据以检验以下假设：“在三叉神经节细胞培养模型中诱导HSV-1再活化的所有病毒蛋白通过（a）诱导ICP 0，（B）抑制LAT转录，或（c）两者均实现该表型。"

DESCRIPTION (provided by applicant): Recurrent infections with herpes simplex viruses (HSV) are a significant clinical problem. Fundamental to understanding the nature of recurrent herpetic disease is determining precisely how HSV alternates between the two phases of its dual life cycle, latency and reactivation of productive infection. The LAT-ICP0 locus plays a central role in the regulation of HSV-1 latency and reactivation. The genes that encode for the latency-associated transcripts (LATs) and infected cell polypeptide 0 (ICP0) form a continuous locus in the repeated regions of the HSV genome. Specifically, the LAT and ICP0 genes lie on opposite strands of HSV-1's double-stranded DNA genome and share a significant overlap. Thus, the abundant LATs can hybridize to 0.75 kilobases of complementary sequence in ICP0 mRNA. While the antisense arrangement of the LAT-ICP0 locus has long been recognized, the hypothesis that LAT RNAs serve as "antisense repressors" of ICP0 gene expression has not been rigorously analyzed. The juxtaposition of the LAT and ICP0 genes mirrors their opposing roles in latency. While LAT RNAs facilitate the maintenance of HSV latency, expression of ICP0 is necessary and sufficient to induce HSV-1 reactivation. Conversely, failure to express ICP0 is highly conducive to HSV genomes entering a transcriptionally repressed state. Thus, antisense repression of ICP0 mRNA translation is one mechanism by which LATs may facilitate the maintenance of latency. The goal of this research proposal is to evaluate the concept that LAT RNAs and ICP0 form a pair of mutually dependent, opposite regulators that are the yin and yang of HSV latency. Specifically, genetic evidence will be obtained to test the hypothesis that "All viral proteins that induce HSV-1 reactivation in the trigeminal ganglion cell culture model achieve this phenotype via (a) induction of ICP0, (b) suppression of LAT transcription, or (c) both."