MOLECULAR GENETIC ANALYSIS OF NDV PATHOGENESIS

病毒致病机制是一个重要的问题。我们计划遗传，生化， 以及以新城疫病毒(NDV)为模型的生物学研究 系统分析副粘病毒的致病机制。 我们的工具包括曼丹斯基和布拉特的非细胞病变(NC)突变体， 温度敏感突变体，以及这些突变体的回复突变体；所有 这些都来自于致命的和细胞病变的澳大利亚-维多利亚 作为我们的主要病毒类型的病毒株(AV-WT)。此外, 我们描述了各种不同类型的突变体及其回复 来自一组不同的自然产生的新城疫病毒株 在毒力模式和许多相关特性中可在 实验室。在适当的情况下，我们还将使用我们正在扩展的库 抗新城疫病毒蛋白的单抗。 我们将继续探索与细胞致病相关的表型和 毒力，希望确定我们之前发现的总体有效性 与AV-WT的NC突变体一起参与了这两种mRNA的调节 细胞致病性和细胞间扩散。我们将选择NC型突变体 来自另一种强毒和细胞病变的新城疫病毒株，它已经拥有 无毒菌株的某些特性。细胞间传播的突变体 这种菌株已经被分离出来，并将被鉴定。一秒钟 该方法将涉及从无毒菌株中分离出突变株：这些将 包括斑块形成突变体，在存在或不存在的情况下筛选 外源蛋白酶和血吸附阳性斑点形成突变体， 像之前对NC突变体所做的那样进行筛选。 我们将进一步探索已经建立的各种具体机制。 建议参与细胞致病或细胞杀伤。可能的 将通过使用Well来探索特定蛋白质的作用 特征为ts突变体和已知的抗中和突变体 在膜糖蛋白的特定区域发生改变。一个主要的焦点 将探索这些糖蛋白在细胞中的可能作用 杀戮。我们还将探索P蛋白在细胞间的作用 散开。 最后，我们将测试一个假设，该假设调用 核糖体在新城疫病毒总蛋白抑制中的作用 综合。

Viral pathogenesis is an important problem. We plan genetic, biochemical, and biological studies using Newcastle disease virus (NDV) as a model system to analyze paramyxovirus pathogenesis. Our tools include the noncytopathic (nc) mutants of Mandansky and Bratt, temperature sensitive mutants, and revertants of these mutants; all of these are derived from the virulent and cytopathic Australia-Victoria strain (AV-WT) which serves as our principal will type virus. In addition, we describe a variety of different types of mutants and their revertants derived from a selected panel of naturally occurring NDV strains differing in virulence patterns and numerous related properties definable in the laboratory. Where appropriate, we will also employ our expanding library of monoclonal antibodies to NDV proteins. We will continue to explore phenotypes relevant to cytopathogenicity and virulence, hoping to determine the general validity of our previous finding with the nc mutants of AV-WT which have implicated both mRNA modulated cytopathogenicity and cell to cell spread. We will select nc type mutants from another virulent and cytopathic NDV strain which already possesses some characteristics of avirulent strains. Cell to cell spread mutants of this strain have been isolated and will be characterized. A second approach will involve isolating mutants from avirulent strains: these will include plaque forming mutants, screened for in the presence or absence of exogenous protease, and hemadsorption positive spot forming mutants, screened for as previously done for the nc mutants. We will further explore a variety of specific mechanisms which have been suggested to be involved in cytopathogenicity or cell killing. Possible roles of specific proteins will be explored through the use of well characterized ts mutants and neutralization resistant mutants known to be altered in specific regions of the membrane glycoproteins. A major focus will be the exploration of possible roles of these glycoproteins in cell killing. We will also explore the role of the P protein in cell to cell spread. Finally, we will test an hypothesis which invokes a sequestering of ribosomes by non-translatable mRNA in NDV's inhibition of total protein synthesis.