Orlando Joseph S, Balliet John W, Kushnir Anna S, Astor Todd L, Kosz-Vnenchak Magdalena, Rice Stephen A, Knipe David M, Schaffer Priscilla A
Department of Microbiology and Molecular Genetics, Harvard Medical School at the Beth Israel Deaconess Medical Center, 330 Brookline Avenue, RN 123, Boston, MA 02215, USA.
J Virol. 2006 Oct;80(19):9381-90. doi: 10.1128/JVI.01061-06.
The immediate-early regulatory protein ICP22 is required for efficient replication of herpes simplex virus type 1 in some cell types (permissive) but not in others (restrictive). In mice infected via the ocular route, the pathogenesis of an ICP22- virus, 22/n199, was altered relative to that of wild-type virus. Specifically, tear film titers of 22/n199-infected mice were significantly reduced at 3 h postinfection relative to those of mice infected with wild-type virus. Further, 22/n199 virus titers were below the level of detection in trigeminal ganglia (TG) during the first 9 days postinfection. On day 30 postinfection, TG from 22/n199-infected mice contained reduced viral genome loads and exhibited reduced expression of latency-associated transcripts and reduced reactivation efficiency relative to TG from wild-type virus-infected mice. Notably, the first detectable alteration in the pathogenesis of 22/n199 in these tests occurred in the eye prior to the onset of nascent virus production. Thus, ICP22- virions appeared to be degraded, cleared, or adsorbed more rapidly than wild-type virions, implying potential differences in the composition of the two virion types. Analysis of the protein composition of purified extracellular virions indicated that ICP22 is not a virion component and that 22/n199 virions sediment at a reduced density relative to wild-type virions. Although similar to wild-type virions morphologically, 22/n199 virions contain reduced amounts of two gamma2 late proteins, US11 and gC, and increased amounts of two immediate-early proteins, ICP0 and ICP4, as well as protein species not detected in wild-type virions. Although ICP22- viruses replicate to near-wild-type levels in permissive cells, the virions produced in these cells are biochemically and physically different from wild-type virions. These virion-specific differences in ICP22- viruses add a new level of complexity to the functional analysis of this immediate-early viral regulatory protein.
即刻早期调节蛋白ICP22是1型单纯疱疹病毒在某些细胞类型（允许性细胞）中高效复制所必需的，但在其他细胞类型（限制性细胞）中则不然。在经眼部途径感染的小鼠中，ICP22缺陷病毒22/n199的发病机制相对于野生型病毒发生了改变。具体而言，与感染野生型病毒的小鼠相比，感染22/n199的小鼠在感染后3小时泪膜滴度显著降低。此外，在感染后的前9天，22/n199病毒滴度低于三叉神经节（TG）的检测水平。在感染后第30天，与野生型病毒感染小鼠的TG相比，感染22/n199的小鼠的TG中病毒基因组负荷降低，潜伏相关转录本的表达减少，再激活效率降低。值得注意的是，在这些试验中，22/n199发病机制中第一个可检测到的改变发生在新生病毒产生之前的眼部。因此，ICP22缺陷病毒粒子似乎比野生型病毒粒子降解、清除或吸附得更快，这意味着两种病毒粒子类型的组成可能存在差异。对纯化的细胞外病毒粒子的蛋白质组成分析表明，ICP22不是病毒粒子的组成成分，并且22/n199病毒粒子的沉降密度相对于野生型病毒粒子降低。尽管22/n199病毒粒子在形态上与野生型病毒粒子相似，但它含有较少的两种γ2晚期蛋白US11和gC，以及较多的两种即刻早期蛋白ICP0和ICP4，还有在野生型病毒粒子中未检测到的蛋白质种类。尽管ICP22缺陷病毒在允许性细胞中复制至接近野生型水平，但在这些细胞中产生的病毒粒子在生化和物理性质上与野生型病毒粒子不同。ICP22缺陷病毒中这些病毒粒子特异性差异为这种即刻早期病毒调节蛋白功能分析增加了新的复杂层面。
