The Role of Babesia bovis MSA-1 in Erythrocyte Invasion

牛巴贝虫 MSA-1 在红细胞侵袭中的作用

• 批准号: 6750121
• 负责人: Tanya LeRoith
• 金额: $ 8.24万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6750121
• 关键词: Babesia; antibody titering; antigen antibody reaction; antisense nucleic acid; babesiosis; binding proteins; biological models; blocking antibody; cell line; cell sorting; cow; erythrocyte membrane; gene induction /repression; gene targeting; genetic translation; host organism interaction; immune adherence reaction; immunocytochemistry; intracellular parasitism; molecular cloning; plasmids; protein biosynthesis; protein structure function; protozoal antigen; site directed mutagenesis; surface antigens; transfection /expression vector

DESCRIPTION (provided by applicant): Apicomplexan parasites in the genera Babesia and Plasmodium infect mature erythocytes and cause disease in animals and humans. A principal vaccine strategy is to direct immune responses against merozoite surface proteins and block entry into the host erythrocyte. While parasite proteins involved in invasion have been identified, the function of these proteins and the molecular mechanisms of invasion are major gaps in our knowledge. I propose to use Babesia bovis infection of bovine erythrocytes as a model to investigate the function of merozoite surface proteins in invasion. Based on the ability of antibodies against B. bovis merozoite surface antigen-1 (MSA-1) to prevent merozoite attachment to the erythrocyte and inhibit erythrocyte invasion in vitro, MSA-l has been postulated to mediate merozoite attachment to the erythrocyte. In addition, breakthrough isolates in vaccinated cattle express allelic variants of MSA-1, suggesting selection of MSA-1 variants under immune pressure. Therefore, I am interested in better understanding the role of MSA-l in invasion with the goal of defining conserved molecular targets for immunization. The research outlined in this proposal will test the hypothesis that merozoite surface antigen-1 (MSA-1) of Babesia bovis mediates erythrocyte invasion through binding to the erythrocyte surface. The hypothesis will be tested through the following specific aims: Specific aim 1: Determine if B. bovis MSA-1 binds to the erythrocyte surface. Specific aim 2: Determine if inhibition of MSA-l expression disrupts parasite binding to the erythrocyte. Specific aim 3: Determine if disruption of the msa-l gene inhibits parasite binding to and invasion of erythrocytes. The primary purposes of this research are to increase our understanding of the mechanisms of erythrocyte invasion used by babesial parasites, and to develop a system for investigating the function of other babesia1 molecules using genetic manipulation. The information obtained will expand our knowledge of comparative invasion mechanims used by apicomplexan hemoparasites, including Babesia and Plasmodium spp that infect humans. The results of this project, as well as the transfection techniques that will be developed, will allow us to begin targeting regions of functional significance in these proteins for further study.

描述（由申请人提供）： 顶复门寄生虫属 巴贝虫和疟原虫感染成熟红细胞并引起动物疾病 和人类。 主要的疫苗策略是引导免疫反应 对抗裂殖子表面蛋白并阻止进入宿主红细胞。 虽然参与入侵的寄生虫蛋白已被识别， 这些蛋白质的功能和入侵的分子机制是主要的 我们的知识差距。 我建议用牛巴贝斯虫感染牛 以红细胞为模型研究裂殖子表面功能 入侵中的蛋白质。 基于抗牛双歧杆菌抗体的能力 裂殖子表面抗原 1 (MSA-1) 可防止裂殖子附着在 MSA-l 在体外具有抑制红细胞侵袭的作用 推测介导裂殖子附着于红细胞。 此外， 接种疫苗的牛中突破性分离株表达 MSA-1 等位基因变体， 建议在免疫压力下选择 MSA-1 变体。 因此，我是 有兴趣更好地了解 MSA-l 在入侵中的作用，目标是 定义免疫的保守分子靶点。 研究 该提案中概述的将检验裂殖子表面的假设 牛巴贝虫抗原1（MSA-1）通过介导红细胞侵袭 与红细胞表面结合。 该假设将通过以下方式进行检验 具体目标如下： 具体目标 1：确定 B. bovis MSA-1 是否结合 红细胞表面。 具体目标 2：确定 MSA-1 是否受到抑制 表达破坏寄生虫与红细胞的结合。 具体目标3： 确定 msa-l 基因的破坏是否会抑制寄生虫与 红细胞的侵袭。 这项研究的主要目的是加深我们对 巴贝斯寄生虫利用红细胞入侵的机制，并发展 研究其他巴贝虫1分子功能的系统 基因操纵。 获得的信息将扩展我们的知识 顶端复门血寄生虫使用的比较入侵机制，包括 感染人类的​​巴贝虫属和疟原虫属。 这个项目的结果， 以及将要开发的转染技术，将使我们能够 开始针对这些蛋白质中具有功能意义的区域 进一步研究。