Molecular escape mechanisms of Theileria parasites

泰勒虫寄生虫的分子逃逸机制

• 批准号: 07406019
• 负责人: ONUMA Misao
• 金额: $ 7.94万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07406019/
• 关键词: Theileria parasites; piroplasm; evasion mechanism; parasite genotype; tick; 原虫表面抗原遺伝子; ダニ体内の有性生殖; 持続感染; 抗原多型性; バキュロウィルス発現系; 表面抗原; PCR; Theileria parasites; piroplasm; evasion mechanism; parasite genotype; tick; 原虫表面抗原遺伝子; ダニ体内の有性生殖; 持続感染; 抗原多型性; バキュロウィルス発現系; 表面抗原; PCR

Theileria sergenti is a tick-borne protozoa of cattle. T.sergenti infected calves show persistent infection, possibly over their life span, but the mechanisms by which the parasites evade host defense mechanisms are not clearly understood. The complete life-cycle of T.sergenti in the mammalian host and tick vector remains unclear, the parasite may undergo a sexual stage in tick gut. To study the population changes during persistent infection in cattle and vector ticks, we have inoculated T.sergenti which consist of 2 parasite populations with C and I type allele of p32 and analyzed the population changes by allele-specific PCR to differentiate between individual types of parasites. Changes in a dominant parasite population were demonstrated during transmission from calves to the tick vector and from infected ticks to calves. The antigenic diversity which may be produced at the sexual stage in tick vector. The analysis of chromosome provide us the basic information to study the generation of genetic and antigenic polymorphism.Chromosome analysis of T.sergenti showed 4 chromosomes. From the results of Southern blot analysis, p32 gene was located on the 1st chromosome, p23, heat shock protein 70 (HSP 70) and cystein proteinase genes were on the chromosome 2 and ribosomal RNA gene was on chromosomes 1 and 3/4.

Theileria Sergenti是牛tick虫的原生动物。 T.Serergenti感染的犊牛可能在其寿命范围内显示出持续的感染，但是寄生虫逃避宿主防御机制的机制尚不清楚。 T.Sergenti在哺乳动物宿主和壁虱矢量中的完整生命周期尚不清楚，寄生虫可能会在tick肠中经历性阶段。为了研究牛和载体tick虫持续感染期间的种群变化，我们接种了T.Sergenti，由2个寄生虫种群组成，c和i键入p32等位基因，并分析了等位基因特异性PCR的种群变化以区分各个类型的寄生虫。在从犊牛到壁虱载体的传播过程中以及从感染的滴答到犊牛的传播过程中，证明了主要的寄生虫种群的变化。可以在tick矢量的性阶段产生的抗原多样性。染色体的分析为我们提供了基本信息，以研究遗传和抗原多态性的产生。染色体的染色体分析显示了4个染色体。从Southern印迹分析的结果中，p32基因位于第1染色体上，p23，热休克蛋白70（HSP 70）（HSP 70）和Cystein蛋白酶基因在2号染色体上，核糖体RNA基因在1和3/4的染色体上呈​​核糖体RNA基因。