Studies in Poxvirus Host Range Genes and Tropism

项目摘要 我们建议研究介导一个物种特异性和向性的分子途径 特别是痘病毒，即粘液瘤病毒（MV）。MV是一种兔特异性痘病毒， 疾病谱取决于特定的兔种属，但对所有其他宿主种属均无致病性， 包括人类。我们的实验室已经广泛研究了MV和它在兔子身上引起的疾病，称为粘液瘤病， 作为研究痘病毒发病机理的基本原理的模型系统，特别是通过利用 我们大量且不断增长的靶向MV基因敲除构建体的集合。几年前，我们 出乎意料地发现，通常不允许MV感染的原代小鼠细胞， 通过中断细胞干扰素（IFN）应答使其完全允许。这项工作随后导致了 发现测试的大多数人类癌细胞对MV是完全允许的，并且MV是 作为溶瘤疗法在治疗各种动物中的人癌症异种移植物中显著有效 模型我们还发现两个病毒宿主范围因子（M-T5和M063）也对允许的 MV在许多人类癌细胞中复制，我们可以操纵病毒的容许性和溶瘤作用， 通过这些病毒蛋白和它们的宿主细胞蛋白靶点。最后，我们最近的观察与以下方面有关： 该建议是IFN和肿瘤协同保护原代人细胞免受MV感染， 坏死因子（TNF）。我们建议： 1-评估病毒宿主范围因子在MV对人类癌细胞的嗜性中的作用。我们提出 分析MV宿主范围蛋白与宿主细胞信号分子（如Akt）的相互作用， 诱变、siRNA敲除、信号传导抑制剂和蛋白质微阵列。我们将测试一些 辅助策略，如用于人类癌症化疗的信号调节剂药物，以增加MV 对更广泛的人类癌细胞具有溶瘤潜力。 2-研究宿主IFN和TNF应答在MV嗜性中的作用。我们将研究MV淘汰赛 在几个关键的病毒宿主范围基因中缺失的病毒，以研究它们在抑制IFN 或TNF应答，以及调节MV向性和溶瘤。这一新信息将允许更多 合理的方法来优化MV病毒治疗对更广泛的人类癌症， 控制MV在原代非癌人类细胞中的复制。

Project Summary We propose to examine the molecular pathways that mediate the species specificity and tropism of one particular poxvirus, namely myxoma virus (MV). MV is a rabbit-specific poxvirus that induces distinctly different disease profiles depending on the specific rabbit species but is nonpathogenic for every other host species, including man. Our lab has extensively studied MV and the disease it causes in rabbits, called myxomatosis, as a model system to investigate the fundamental principles of poxvirus pathogenesis, particularly by exploiting our large and growing collection of targeted MV gene knockout constructs. Several years ago, we unexpectedly discovered that primary mouse cells, which are normally nonpermissive for MV infection, could be rendered fully permissive by interrupting the cellular interferon (IFN) responses. This work then led to the discovery that the majority of human cancer cells tested were fully permissive for MV and that MV is remarkably effective as oncolytic therapy for the treatment of human cancer xenografts in a variety of animal models. We also discovered that two viral host range factors (M-T5 and M063) were also critical for permissive MV replication in many human cancer cells and we could manipulate viral permissiveness and oncolysis through these viral proteins and their host cell protein targets. Finally, our most recent observation related to this proposal is that primary human cells are protected from MV infection synergistically by IFN and tumor necrosis factor (TNF). We propose to: 1- Evaluate the roles of viral host range factors in MV tropism for human cancer cells. We propose to analyze the interactions of MV host range proteins with host cell signaling molecules (like Akt) by mutagenesis, siRNA knockdowns, signaling inhibitors and protein microarrays. We will test a number of adjunct strategies, like signaling modifier drugs used for cancer chemotherapy in man, to increase MV oncolytic potential for a wider spectrum of human cancer cells. 2- Investigate the role of host IFN and TNF responses in MV tropism. We will study MV knockout viruses that are deleted in several key viral host range genes to investigate their roles in inhibiting IFN or TNF responses, and modulating MV tropism and oncolysis. This new information will allow for more rational approaches to optimizing MV virotherapy against a wider spectrum of human cancers, and for controlling MV replication in primary noncancerous human cells.