STRUCTURAL AND FUNCTIONAL ANALYSIS OF ENDOGENOUS PROVIRUSES OF MICE

小鼠内源原病毒的结构和功能分析

• 批准号: 3822045
• 负责人: A S KHAN
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3822045
• 关键词: Retroviridae disease; autoimmune disorder; chromosomes; gene expression; genetic manipulation; genetic mapping; genetic recombination; genetic regulation; genetic strain; genetic transcription; genome; murine leukemia virus; neoplasm /cancer genetics; nucleic acid sequence; oncogenic virus; provirus; thymus neoplasms; viral leukemogenesis; virulence; virus DNA; virus RNA; virus envelope; virus genetics

Mouse genome contains at least 50 copies of murine leukemia viral (MuLV)-related DNAs, the majority of which are defective. Recombination between different infectious and defective MuLV sequences results in the generation of novel MuLVs including lymphomagenic mink cell focus-forming (MCF) viruses. The main goals of this project are: 1) to study the structure and regulation of expression of endogenous defective MuLV proviral DNAs; 2) to study generation of recombinant MCF viruses; and 3) to identify sequences contributing to leukemogenicity of MCF MuLVs. Full-length (8.4 kb) transcripts of endogenous MCF env-related proviruses were highly-expressed in thymus tissues of autoimmune mouse strains but were not detectable in nonautoimmune strains. The 8.4 kb RNA species was detected from day 1 of life in NZB mice, prior to clinical manifestations of autoimmune disease. The data indicates that the expression of endogenous MCF-related DNAs is regulated differently in autoimmune versus non- autoimmune mouse strains. An MCF LTR-specific DNA probe was constructed to identify MuLV proviruses which could donate LTR sequences to generate recombinant MCF MuLVs. Two potential LTR-progenitors were detected; one contained xenotropic env-related sequences and was chromosomally mapped as the inducible, endogenous xenotropic MuLV locus, Bxv-1; the second was characterized as a novel endogenous MuLV provirus which was related in env to MCF MuLVs. The latter MuLV DNA was conserved in the genomes all inbred and several wild mice. To study the contribution of the integrase gene in MCF-induced thymomas, a 2.7 kb DNA segment containing the 3' pol region of leukemogenic MCF13 was substituted by an analogous segment from non-leukemogenic MCF111A MuLV DNA. The recombinant virus obtained from transfection studies was injected into newborn AKR mice to test whether the MCF viral genome retained its leukemogenic potential with the substituted integrase gene. Tumor development was delayed and the incidence of thymomas was reduced by 50%. These results suggest that the integrase gene contributes to leukemogenicity of MCF viruses.

小鼠基因组含有至少50个小鼠白血病拷贝 病毒（MuLV）相关DNA，其中大多数是有缺陷的。 不同感染性和缺陷性MuLV之间的比较 序列导致产生新的MuLV，包括 淋巴瘤性水貂细胞病灶形成（MCF）病毒。 主要 本项目的目标是：1）研究结构和调节 内源性缺陷型MuLV前病毒DNA表达; 2） 研究重组MCF病毒的产生;和3）鉴定 导致MCF MuLV的白血病发生的序列。 内源性MCF env相关基因的全长（8.4 kb）转录本 原病毒在自身免疫性胸腺组织中呈高表达 小鼠品系，但在非自身免疫性品系中检测不到。 在NZB中，从生命的第1天起检测到8.4kb RNA种类 小鼠，在自身免疫性疾病的临床表现之前。 的 数据表明，内源性MCF相关基因的表达 DNA在自身免疫性与非自身免疫性中的调节不同。 自身免疫小鼠品系。 构建了MCF LTR特异性DNA探针，以鉴定 MuLV前病毒可以提供LTR序列以产生 重组MCF MuLV。 两个潜在的LTR祖细胞是 检出;一个含有异嗜性env相关序列， 在染色体上被定位为诱导型，内源性 异嗜性MuLV基因座，Bxv-1;第二个被表征为 一种新的与MCF相关的内源性MuLV前病毒 MuLV。 后者MuLV DNA在所有的基因组中是保守的， 近交系和几只野生小鼠。 研究整合酶基因在MCF-7细胞诱导分化中的作用， 胸腺瘤，一个2.7 kb的DNA片段，含有胸腺瘤的3' pol区域， 致白血病的MCF 13被类似的片段取代， 来自非致白血病的MCF 111 A MuLV DNA。 重组 将从转染研究中获得的病毒注射到 新生的AKR小鼠来测试MCF病毒基因组是否 保留了其潜在的白血病与取代整合酶 基因 肿瘤发展延迟， 胸腺瘤减少了50%。 这些结果表明 整合酶基因有助于MCF病毒的致白血病性。