BASIS FOR THE IFP PHENOTYPE OF DIABETOGENIC EMC VIRUS

糖尿病性 EMC 病毒 IFP 表型的基础

• 批准号: 3232583
• 负责人: GEORGE W JORDAN
• 金额: $ 14.84万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-07-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3232583
• 关键词: autoradiography; complementary DNA; encephalomyocarditis virus; gel electrophoresis; gene expression; genetic manipulation; genetic mapping; genetic strain; genetic translation; insulin dependent diabetes mellitus; interferons; laboratory mouse; molecular cloning; nucleic acid chemical synthesis; nucleic acid probes; nucleic acid sequence; pancreatic islet disorder; plasmids; tissue /cell culture; transfection; virus RNA; virus genetics; virus related diabetes mellitus

Encephalomyocarditis (EMC) virus induced diabetes mellitus in mice has similarities to a subset of juvenile onset diabetes in humans. Two otherwise similar variants derived from the M- strain of EMC virus are available for study that differ in their interferon inducing particle (ifp) phenotype and in their ability to cause diabetes in mice. The EMC-B variant is ifp+, produces high levels of circulating interferon (IFN) in infected mice, causes limited infection of pancreatic islets, and does not cause diabetes. When circulating IFN is neutralized by anti-IFN globulins, diabetes results from infection with EMC-B indicating that the interferon system, possibly the ifp phenotype, is a determinant of the diabetic outcome. The EMC-D variant is ifp-, produces lower levels of circulating IFN, destroys pancreatic islets and causes diabetes in mice. Key genetic differences must be responsible for the different biological properties of these closely related viruses. In order to determine the genetic basis for these properties we have cloned cDNA corresponding to the complete open reading frame of both variants. Their restriction endonuclease maps are identical for 12 different enzymes. Also, the first 103 nucleotides of the untranslated RNA at the 5' end of the genomes are identical. We propose to discover the genetic basis for the ifp phenotype and diabetogenicity of EMC virus by first comparing the complete nucleotide sequences of the B and D variants. The functional significance of differences in nucleotide sequence that are found to occur in the open reading frame will be ascertained by reference to the in vitro translation products of RNA transcripts and to the known functions of EMC viral proteins. Complete cDNA of the B and D variants will be synthesized for transfection of mammalian cells. With reference to differences in nucleotide sequence within or outside the open reading frame, chimeric molecules of B and D will be synthesized. The biological properties of the recombinant viruses will be determined in order to independently determine the genetic locus responsible for the ifp phenotype and diabetogenicity. This knowledge will further our understanding of virus virulence and the mechanism of interferon induction by viruses. Using data provided by this project, it may be possible to predict the virulence of human viruses from a knowledge of genetic structure.

脑心肌炎（EMC）病毒诱发糖尿病 小鼠与青少年发病的糖尿病的一个子集有相似之处 人类。 源自 M- 的两个其他相似变体 EMC 病毒株可用于研究，其不同之处在于 干扰素诱导颗粒（ifp）表型及其能力 引起小鼠糖尿病。 EMC-B 变体是 ifp+，产生高 受感染小鼠体内循环干扰素 (IFN) 水平升高，导致 胰岛感染有限，并且不会引起糖尿病。 当循环中的干扰素被抗干扰素球蛋白中和时， 糖尿病是由 EMC-B 感染引起的，表明 干扰素系统，可能是 ifp 表型，是 糖尿病的结果。 EMC-D 变体是 ifp-，产生更低的 循环干扰素水平，破坏胰岛并导致 小鼠糖尿病。 关键的遗传差异必须负责 这些密切相关的病毒的不同生物学特性。 为了确定这些特性的遗传基础，我们 已经克隆了与完整开放阅读相对应的cDNA 两种变体的框架。 他们的限制性内切酶图谱是 12 种不同的酶是相同的。 另外，前 103 个核苷酸 基因组 5' 端的非翻译 RNA 是 完全相同的。 我们建议发现 ifp 的遗传基础 通过首先比较 EMC 病毒的表型和致糖尿病性 B和D变体的完整核苷酸序列。 这 核苷酸序列差异的功能意义 发现发生在开放阅读框中将被确定 参考RNA体外翻译产物 转录本和 EMC 病毒蛋白的已知功能。 B 和 D 变体的完整 cDNA 将被合成 哺乳动物细胞的转染。 参考差异 在开放阅读框内或外的核苷酸序列中， 将合成B和D的嵌合分子。 生物的 重组病毒的特性将按顺序确定 独立确定负责的遗传位点 ifp 表型和致糖尿病性。 这些知识将进一步 我们对病毒毒力及其机制的了解 病毒诱导干扰素。 使用本提供的数据 项目，有可能预测人类的毒力 病毒来自遗传结构的知识。