MECHANISM OF ANTIGENIC VARIATION IN TRYPANOSOMA BRUCEI

布氏锥虫抗原变异机制

• 批准号: 3132137
• 负责人: L H T VAN DER PLOEG
• 金额: $ 33.25万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3132137
• 关键词: DNA directed RNA polymerase; Trypanosoma; biological polymorphism; chromosome translocation; gene expression; gene mutation; genetic manipulation; genetic recombination; genetic transcription; genome; glycoproteins; immunogenetics; laboratory mouse; laboratory rabbit; laboratory rat; membrane activity; membrane proteins; microorganism genetics; microorganism immunology; molecular cloning; molecular genetics; mutant; nucleic acid probes; nucleic acid sequence; parasitic disease chemotherapy; protozoal antigen; trypanosomiasis

Trypanosomes and related protozoan parasites cause a range of diseases man and his livestock (e.g. Chagas disease and sleeping sickness). The blood-dwelling parasite Trypanosoma brucei escapes immune-destruction through antigenic variation, by periodically changing the production of one variant cell surface glycoprotein (VSG) coat to the next. We will study the genetic basis of immune- evasion. The focus will be on transcriptional control of VSG genes and on understanding the importance of expression site, chromosome and nuclear structure for VSG gene activation. We will also study the biological role of expression site associated genes, that are coordinately transcribed with the VSG gene. We are particularly interested in transcription of VSG genes by a novel type of RNA polymerase that is insensitive to the drug alpha- amanitin. We will characterize this RNA polymerase and compare its transcriptional specificity to that of other eukaryotic RNA polymerases. We will test drugs for their capability to interfere with transcription switching of VSG genes. We will survey the importance of transcription of protein-coding genes by alpha- amanitin insensitive RNA polymerases in trypanosomes and related kinetoplastida. These studies are aimed at understanding the biological role of transcription of protein coding get by RNA polymerase II and another as yet unidentified RNA polymerase. A rationale for drug therapy may result. To facilitate the molecular analysis of these protozoan parasites will further develop a DNA transfection system for T.brucei. We will construct vectors that can be used to introduce foreign genes into trypanosomes. The vectors will be engineered to resemble VSG gene expression sites with which chromosomal rearrangements and transcript control of VSG genes will be studied.

锥虫和相关原生动物寄生虫会引起一系列 人类及其牲畜的疾病（例如查加斯病和睡眠病） 疾病）。 血液寄生虫布氏锥虫逃脱 通过抗原变异破坏免疫系统 改变一种变异细胞表面糖蛋白的产生 （VSG）外套到下。 我们将研究免疫的遗传基础 逃避。 重点是 VSG 基因的转录控制 并了解表达位点、染色体的重要性 和VSG基因激活的核结构。 我们也会学习 表达位点相关基因的生物学作用，即 与 VSG 基因协调转录。 我们对 VSG 基因的转录特别感兴趣 新型RNA聚合酶，对药物α-不敏感 鹅膏蕈碱。 我们将表征这种 RNA 聚合酶并进行比较 其与其他真核生物 RNA 的转录特异性 聚合酶。 我们将测试药物的干扰能力 VSG 基因的转录转换。 我们将调查 α-蛋白质编码基因转录的重要性 锥虫及相关动物中鹅膏蕈碱不敏感的RNA聚合酶 动质体。 这些研究旨在了解 RNA 编码蛋白质转录的生物学作用 聚合酶 II 和另一种尚未鉴定的 RNA 聚合酶。 一个 可能会产生药物治疗的理由。 促进这些原生动物寄生虫的分子分析 将进一步开发T.brucei的DNA转染系统。 我们 将构建可用于引入外源基因的载体 进入锥虫。 这些载体将被设计为类似于 VSG 染色体重排和基因表达位点 将研究VSG基因的转录控制。