Autophagy and ER stress during varicella infection

最近在感染水痘的两个培养细胞中都证明了自噬- 带状疱疹病毒(VZV)以及人类带状疱疹病毒水泡中也存在这种病毒。点状自噬小体的存在 在带状疱疹皮肤水泡中，坚定地确立了自噬(巨型自噬)是一种相关的生物学 在这种疱疹病毒引起的疾病的自然历史过程中。重要的是，我们有 进行了充分的初步研究，以证明VZV感染引起的自噬 与单纯疱疹病毒诱导的自噬不同。首先，VZV基因组缺乏与VZV同源的 单纯疱疹病毒ICP34.5基因。第二，我们现在已经通过两种不同的方法表明，VZV感染 迅速诱发明显的内质网应激，这是HSV系统中未知的事件。因此， 重申这一建议的中心假设是内质网应激是VZV的关键组成部分 感染，内质网应激与内质网中错误折叠的VZV糖蛋白过多有关， 内质网相关的降解和自噬是缓解内质网应激的结果。这些 这些事件允许受感染的细胞存活更长时间，以避免细胞凋亡，从这个意义上说， 被认为是支持病毒的。检验这一假设的研究计划涉及三个具体目标。目标 1被称为VZV诱导内质网应激的自噬诱导。Aim 2被称为 VZV诱导内质网应激激活未折叠蛋白应答(UPR)。目标3，它 涉及A.Arvin实验室，包括SCID-HU中自噬和内质网应激的研究 小鼠模型，感染各种重组突变的VZV基因组。在我们的 研究计划，我们将继续通过扩大实验方法进行先前的调查 定向到从内质网应激到UPR的三条传感器通路(IRE1、ATF6和 福利)。我们已经在VZV感染细胞中检测到四种与UPR相关的蛋白质， 包括BiP(HSPA5)、HSPA8、HSPD1和PPIA：肽-丙基-顺式-反式异构酶)。更多 最近，我们在VZV感染细胞中检测到了XBP1(X盒结合蛋白)的剪接体， 普遍定期审议的另一个标志。最后的方法将包括已经进行的动物实验 制备了含有大量GE突变的重组病毒。这些突变体的表型 病毒已经在细胞培养和SCID小鼠模型中被确定。因此， 上述实验计划将确定内质网应激和自噬在 细胞对VZV感染的反应。这些结果不仅与我们对 接种水痘疫苗还会引起与带状疱疹相关的虚弱疾病，称为带状疱疹后神经痛。

Autophagy has recently been demonstrated in both cultured cells infected with varicella- zoster virus (VZV) as well as in a human zoster vesicle. The presence of punctate autophagosomes in a zoster skin vesicle firmly established that autophagy (macroautophagy) is a relevant biological process during the natural history of disease caused by this herpesvirus. Of importance, we have carried out sufficient preliminary studies to document that autophagy induced by VZV infection does not resemble HSV-induced autophagy. First of all, the VZV genome lacks a homolog of the HSV ICP 34.5 gene. Secondly, we have now shown by two different methods that VZV infection quickly induces marked ER stress, an event not known to occur in the HSV system. Therefore, the re-stated central hypothesis for this proposal is that ER stress is a critical component of VZV infection, that ER stress is related to an over abundance of misfolded VZV glycoproteins in the ER, and that ER-associated degradation and autophagy are consequences that relieve ER stress. These events allow the infected cell to survive longer, to avoid apoptosis, and in that sense can be considered pro-viral. The Research Plan to test this hypothesis involves three Specific Aims. Aim 1 is called Induction of autophagy as a consequence of VZV induced ER stress. Aim 2 is called Activation of the unfolded protein response (UPR) by VZV induced ER stress. Aim 3, which involves the A. Arvin laboratory, includes Studies of autophagy and ER stress in the SCID-hu mouse model, following infection with various recombinant mutated VZV genomes. In our Research Plan, we will continue prior investigations with an expanded experimental approach directed toward the three sensor pathways that lead from ER stress to the UPR (IRE1, ATF6 and PERK). We have already detected four proteins associated with the UPR in VZV infected cells, including BiP (HSPA5), HSPA8, HSPD1 and PPIA: peptidyl-propyl-cis-trans-isomerase). More recently we have detected the spliced form of XBP1 (X-Box binding protein) in VZV infected cells, another marker of the UPR. The final approach will include animal experiments with already prepared recombinant viruses containing numerous gE mutations. The phenotypes of these mutant viruses have already been determined in both cell culture and the SCID mouse model. Thus the above experimental plan will determine the relative importance of ER stress and autophagy in the cellular response to VZV infection. The results are relevant not only to our understanding of varicella vaccination but also the debilitating zoster-related illness called post-herpetic neuralgia.