SCHISTOSOME HOST/INTERACTIVE SURFACE MEMBRANE PROTEINS

血吸虫是细胞外的血吸虫， 在人体血管系统中的时间。由于蠕虫之间 与其宿主，执行功能，如营养吸收， 通常由整体表面膜进行的附着 蛋白质，寄生虫必须发展机制，以避免 针对这些蛋白质的免疫攻击。我们的目标是确定 这些功能性的、暴露于宿主的、多体的膜蛋白是否可以 成为血吸虫病疫苗的有效靶点如果成功，这 新的疫苗接种策略也应该对其他 由蠕虫寄生虫引起的疾病。 为了实现我们的目标，我们已经获得了几个全长血吸虫 mansoni cDNA克隆，其中三个编码表面膜蛋白， 我们已经证明，在生活中， 蠕虫包括葡萄糖转运蛋白，氨基酸通透酶 同源物和表面抗原SM 23。所有这些都被表达为高 重组昆虫细胞内的水平。在本申请中，我们提出 把我们的努力集中在三个真正的令人讨厌的主机互动 膜蛋白（HIMPs），并进行决定性的研究， 确定HIMPs是否可以成为有效血吸虫病治疗的靶点 疫苗我们将使用构象天然的重组蛋白 和裸DNA表达质粒作为免疫原诱导细胞和/或 针对HIMP上的宿主暴露表位的体液免疫应答。 将测试成功免疫的小鼠的抵抗能力， 血吸虫感染。重组抗体（rAb）文库将 从成功免疫小鼠的脾脏中产生并筛选 用于显示表面表位识别的克隆。纯化的rAbs来自 将测试阳性克隆的被动转移能力， 防止尾蚴感染。宿主暴露的表位将是 确定并用于设计改进的候选疫苗。

Schistosomes are extracellular blood flukes that can survive for many years within the human vascular system. Since the worms interact closely with their host, performing functions such as nutrient uptake and attachment that are normally performed by integral surface membrane proteins, the parasites must have developed mechanisms for avoiding immune attack directed at these proteins. Our goal is to determine whether these functional, host-exposed, schistosome membrane proteins can be effective targets of a schistosomiasis vaccine. If successful, this novel vaccination strategy should also be effective against other diseases caused by helminth parasites. Towards our goal, we have obtained several full-length Schistosoma mansoni cDNA clones, three of which encode surface membrane proteins that we have shown to be present at the host/parasite interface in living worms. These include a glucose transporter, an amino acid permease homologue and the surface antigen, SM23. All have been expressed to high levels within recombinant insect cells. In this application, we propose to focus our efforts on the three bona fide schistosome host-interactive membrane proteins (HIMPs) and perform the definitive studies that win ascertain whether HIMPs can be targets of an effective schistosomiasis vaccine. We will use both conformationally native, recombinant protein and naked DNA expression plasmids as immunogens to induce cellular and/or humoral immune responses against host-exposed epitopes on the HIMPs. Successfully immunized mice will be tested for their ability to resist schistosome infection. A library of recombinant antibodies (rAbs) will be generated from the spleens of successfully immunized mice and screened for clones that display surface epitope recognition. Purified rAbs from positive clones will be tested for their ability to passively transfer protection against cercariaI infection. Host-exposed epitopes will be determined and used to design improved vaccine candidates.