Pathogenesis and Gene Regulation of Entomopoxvirus

描述（由申请人提供）：昆虫痘病毒（EPV）是最常见的 脊椎动物正痘病毒（OPV）的远亲，如牛痘（VV） 和天花。脊椎动物痘病毒，特别擅长 转移受感染宿主的免疫和其他防御反应。我们有 完成了来自Amsacta moorei（AmEPV）的EPV的基因组序列，AmEPV是 可以容易地在细胞培养物中生长并且容易地 被操纵了AmEPV引起昆虫的致死性传播感染，但 缺乏免疫修饰基因已知作为毒力因子， 脊椎动物痘病毒我们计划重点关注AmEPV感染的主要方面 舞毒蛾（LD）幼虫作为痘病毒发病机制的模型 在低等真核生物中。我们有三个具体目标。第一个具体目标是 量化和完全表征感染的幼虫的病理学 AmEPV通过直接注射或喂食（经口）。这些研究将 包括感染全程、传播评估、产量 细胞参与。在我们的第二个具体目标，我们将确定为什么AmEPV， 与任何其它已知的痘病毒不同，痘病毒编码病毒的第三或“额外”亚单位， 编码poly（A）聚合酶，一种病毒mRNA合成所必需的酶。这 这种病毒的不寻常特征使人们有可能深入了解这种病毒的一些基本生物学特征。 控制所有痘病毒的基因表达。在第三个具体目标中，我们将 研究特定基因在AmEPV感染的病理生物学中的作用。我们 最初将集中在“Kunitz型”蛋白酶抑制剂和1365 氨基酸ABC转运蛋白基因，这两种基因都没有在任何文献中报道过。 其他病毒。我们将开始产生“淘汰赛”使用的程序， 基因设计还能告诉我们基因是否是生长所必需的。病毒 将评估所选基因的缺失对发病机制的影响。我们 我还计划扩展这些研究，并检查病毒编码的超氧化物 作为其它抗氧化剂的例子， 可能在感染过程中发挥重要作用的基因。每个基因 将进行生化功能评估。总体而言，拟议的 实验将阐明增加的多样性， 宿主生物的防御。

DESCRIPTION (provided by applicant): Entomopoxviruses (EPV's) are the most distant relatives of vertebrate orthopoxviruses (OPV's) such as vaccinia (VV) and variola (smallpox). Vertebrate poxviruses, are particularly masterful in deflecting the immune and other defense responses of the infected host. We have completed the genomic sequence of the EPV from Amsacta moorei (AmEPV), one of the few EPV's which can be easily grown in cell culture and readily manipulated. AmEPV, causes a lethal, disseminated infection of insects but is devoid of the immune modifier genes known to act as virulence factors of vertebrate poxviruses. We plan to focus on the major aspects of AmEPV infection of Lymantria dispar (LD) larvae as a model for the pathogenesis of poxviruses in lower eukaryotes. We have three Specific Aims. The first Specific Aim is to quantify and completely characterize the pathobiology of larvae infected with AmEPV by either direct injection or by feeding (per os). These studies will include a full time course of infection, evaluation of spread, yields and cellular involvement. In our second Specific Aim, we will determine why AmEPV, unlike any other known poxvirus encodes a third or "extra" subunit of the viral encoded poly (A) polymerase, an enzyme essential for viral mRNA synthesis. This unusual feature of the virus promises insight into some of the basic biology of gene expression governing all poxviruses. In our third Specific Aim, we will examine the role of specific genes on the pathobiology of AmEPV infections. We will initially concentrate on a "Kunitz-type" protease inhibitor and a 1365 amino acid ABC transporter gene neither of which have been reported in any other virus. We will begin by generating "knockouts" using a procedure which by design will also tell us whether the gene is essential for growth. Virus deleted for the selected gene will be evaluated for effects on pathogenesis. We also plan to extend these studies and examine virus encoded superoxide dismutase (SOD) and inhibitor of apoptosis protein (IAP) as examples of other genes likely to play significant roles in the infectious process. Each gene will be evaluated for biochemical function. Collectively, the proposed experiments will elucidate added diversity by which viruses counter the defenses of host organisms.