In vivo panning for schistosome protective epitopes

体内淘选血吸虫保护性表位

• 批准号: 6919822
• 负责人: Charles Bix Shoemaker
• 金额: $ 19.81万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-15 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6919822
• 关键词: Schistosoma; Schistosoma mansoni; affinity chromatography; antigen antibody reaction; enzyme linked immunosorbent assay; genetic library; helminthic antigen; host organism interaction; immune response; immunofluorescence technique; immunoglobulin G; laboratory mouse; laboratory rat; phage display; protein engineering; protein localization; proteomics; recombinant proteins; schistosomiasis; surface antigens

DESCRIPTION (provided by the applicant): Schistosomiasis afflicts several hundred million people, causing substantial morbidity and premature death as well as major economic hardship in many developing countries. Over a billion people are at risk of infection. Advances in genomics and proteomics, as well as new technologies such as phage display and recombinant antibodies, offer important new opportunities to develop and test hypotheses relating to these worm parasites and for new schistosomiasis control strategies. Schistosomes are trematode worms that are able to survive for many years within the vasculature of permissive vertebrate hosts. Although schistosomes reportedly possess a variety of immune evasive tools, these blood flukes clearly can become susceptible to immune killing by effectors mediated by antibody directed against the host-exposed tegument. Compelling evidence comes from the rat model, which, unlike mice and humans, becomes strongly immune to schistosomiasis mansoni, and produces antibodies against adult worm surface epitopes that direct the killing of larval and adult schistosomes. Based on these and other data, we hypothesize that schistosomes can be killed in vivo through an immune process that is mediated by protective antibodies directed against a discrete subset of worm surface epitopes. In this R21 grant application, we propose to employ an innovative in vivo phage display technique to identify single-chain antibodies (scFvs) able to bind to the surface of schistosomes as they reside within their host and then test these antibodies for their ability to direct killing of the parasites. The Specific Aims are: #1. Use "in vivo panning" of an antibody (scFv) phage display library prepared from rats immune to schistosomiasis to identify and then characterize host-interactive surface epitopes. #2. Engineer recombinant antibodies that bind to host-interactive schistosome epitopes and test their ability to mediate parasite killing within mice. This research is designed to identify new targets of protective immunity that will serve as vaccine candidates. Furthermore, it will produce new information on the biochemistry of the host-interactive parasite surface in vivo and create genetically modifiable scFv reagents that will lead to a range of unique research opportunities to investigate helminth parasite rejection and immune evasion strategies.

描述（由申请人提供）：血吸虫病困扰着数亿人，在许多发展中国家造成了大量发病和过早死亡以及重大的经济困难。超过十亿人有感染的风险。基因组学和蛋白质组学的进步以及噬菌体显示和重组抗体等新技术为开发和测试与这些蠕虫寄生虫有关的假设以及新的血吸虫病控制策略提供了重要的新机会。血吸虫是能够在允许脊椎动物宿主的脉管系统中生存多年的巨虫蠕虫。尽管据报道，血吸虫具有多种免疫回避工具，但这些血液显然很容易受到针对宿主暴露的TEGUMEMENT介导的抗体介导的效应子的免疫杀伤。令人信服的证据来自大鼠模型，与小鼠和人类不同，该模型对曼森的血吸虫病强烈免疫，并产生针对成年蠕虫表面表位的抗体，这些抗体指导指导杀死幼虫和成年血吸虫。基于这些和其他数据，我们假设可以通过免疫过程在体内杀死血吸虫，该免疫过程是由针对蠕虫表面表位的离散子集的保护性抗体介导的。在此R21赠款应用程序中，我们建议采用创新的体内噬菌体显示技术来识别能够与血块居住在宿主内的血吸虫表面结合的单链抗体（SCFV），然后测试这些抗体，以直接杀死寄生虫。 具体目的是：＃1。使用抗体（SCFV）噬菌体展示库的“体内平移”，从大鼠免疫到血吸虫病的大鼠中，以识别并表征宿主相互作用的表面表位。 ＃2。与宿主相互作用的表位结合并测试其介导小鼠内寄生虫杀死的能力的工程师重组抗体。这项研究旨在确定将作为候选疫苗的保护性免疫的新目标。此外，它将在体内产生有关宿主相互作用寄生虫表面生物化学的新信息，并创建遗传修改的SCFV试剂，从而带来一系列独特的研究机会，以研究蠕虫寄生虫排斥和免疫逃避策略。