Mechanisms of regulation of apoptosis by HSV genes

描述（由申请人提供）：单纯疱疹病毒（HSV）编码 令人惊讶的大量功能旨在阻止主机响应， 感染被HSV阻止的功能列表中包括编程单元 由病毒基因产物的特定功能或外源性 药物（Fas配体、肿瘤坏死因子、热休克或渗透压休克等）。 具体地说，在缺乏几种基因病毒产物之一时，HSV 感染导致细胞凋亡的诱导在多个步骤， 复制周期程序性细胞死亡的诱导和途径可能 依赖于细胞类型。本申请中描述的建议基于 三个关键观察结果：（i）缺乏糖蛋白D（gD）的病毒突变体诱导 凋亡gD突变体诱导的细胞凋亡可被 在反式杆状病毒载体中递送的gD或gJ的表达。(ii)变种人， d120缺乏编码ICP 4（主要调节蛋白）的基因，诱导 在所有测试的细胞系中的细胞凋亡。正在进行的研究表明， 是由ICPO诱导的，ICPO是一种在d120感染的 细胞在d120突变体感染的细胞中产生的ICP 0与野生型ICP 0的不同之处在于 几个属性。d120突变体诱导的细胞凋亡在细胞中被阻断 过表达Bcl-2，也独立地通过病毒蛋白激酶Us 3。（三） 细胞含有DFF 40的复合物（一种负责DNA片段化的DNA酶， 细胞DNA）和DFF 45（其抑制剂）。在细胞凋亡诱导 外源性试剂，细胞色素C被释放，半胱天冬酶被激活，DFF 45被 切割，细胞DNA降解。在感染野生型病毒的细胞中 在渗透压休克诱导下，caspase被激活，但DFF 45被保护 从乳沟。Us 3蛋白激酶似乎参与阻断 DFF 45的裂解。本申请中提出的研究目的 （i）确定gD病毒诱导细胞凋亡的机制， gD或gJ阻止它的手段;（ii）定义ICP 0 诱导细胞凋亡和Us 3阻断它的有效靶点（iii）， 阐明了HSV阻断DFF 45裂解并阻止 细胞DNA的断裂。

DESCRIPTION (provided by applicant): Herpes simplex viruses (HSV) encode a surprisingly high number of functions designed to thwart host responses to infection. Included in the list of function blocked by HSV are programmed cell death induced both by specific functions of viral gene products or by exogenous agents (Fas ligand, tumor necrosis factor, thermal or osmotic shock, etc). Specifically, in the absence of one of several gene viral products, HSV infection results in induction of apoptosis at multiple steps during its replicative cycle. Both the induction and pathway of programmed cell death may be cell type-dependent. The proposal described in this application is based on three key observations: (i) Virus mutants lacking glycoprotein D (gD) induce apoptosis. Apoptosis induced by gD about mutants is blocked independently by expression of gD or gJ delivered in trans bybaculovirus vectors. (ii) A mutant, d120 lacking the gene encoding ICP4, the major regulatory protein, induces apoptosis in all cell lines tested. Studies in progress indicate that apoptosis is induced by ICPO, a promiscuous transactivator overexpressed in d120-infected cells. ICPO made in d120 mutant-infected cells differs from wild type ICP0 in several properties. Apoptosis induced by the d120 mutant is blocked in cells overexpressing Bcl-2 and also independently by viral protein kinase Us3. (iii) Cells contain a complex of DFF40 (a DNase responsible for fragmentation of cellular DNA) and DFF45 (its inhibitor). In cells induced to apoptosis by exogenous agents, cytochrome C is released, caspases are activated, DFF45 is cleaved, and cellular DNA is degraded. In cells infected with wild-type virus and induced by osmotic shock, caspases are activated but DFF45 is protected from cleavage. The Us3 protein kinase appears to be involved in blocking cleavage of DFF45. The objectives of the studies proposed in this application are (i) to determine the mechanisms by which gD- viruses induce apoptosis and the means by which gD or gJ block it; (ii) to defme the mechanism by which ICP0 induces apoptosis and the effective target of Us3 in blocking it (iii) to elucidate the mechanism by which HSV blocks the cleavage of DFF45 and precludes fragmentation of cellular DNA.